tag:theconversation.com,2011:/us/topics/eutrophication-2826/articlesEutrophication – The Conversation2023-11-19T13:00:27Ztag:theconversation.com,2011:article/2151312023-11-19T13:00:27Z2023-11-19T13:00:27Z‘Forever contaminant’ road salts pose an icy dilemma: Do we protect drivers or our fresh water?<p>As winter approaches, many communities in Canada and around the world arm themselves against icy roads and sidewalks with a time-honoured ally: road salt. For decades, applying road salt has been regarded as a simple but vital tool in countering the dangers of slippery road conditions, but the downsides of its use are apparent with implications that <a href="https://doi.org/10.1007/s11270-018-4060-2">extend beyond the cold months</a>. </p>
<p>Scientists have long known that the substance which has safeguarded us through the colder months poses a threat to aquatic life and drinking water quality. But now we are finding that this chemical also <a href="https://doi.org/10.1016/j.scitotenv.2022.157336">disrupts the delicate balance of oxygen and nutrients</a> in our freshwater lakes and ponds. </p>
<p>Road salt, commonly referred to as rock salt, is a mixture primarily composed of sodium chloride (NaCl). It is used to de-ice roads and highways during winter to enhance safety by preventing the formation of ice and reducing slippery conditions. Road salt persists as an environmental contaminant due to its chemical stability and the cyclic nature of its dispersal. </p>
<p>Introduced through activities like road de-icing, salts move from roads to surface water such as streams and lakes, groundwater, remaining indefinitely in the environment without significant degradation. The continual cycling and lack of substantial transformation underscore the long-term impact of sodium chloride as a “forever contaminant.”</p>
<p>With a growing awareness of its ecological repercussions, a critical dilemma emerges. Do we prioritize driver safety or acquatic ecosystem health?</p>
<h2>Negative impacts revisited</h2>
<p>The detrimental effects of road salt on aquatic ecosystems and drinking water supplies <a href="https://doi.org/10.1016/j.scitotenv.2021.150289">have long been recognized</a>. Its heavy application during winter months leads to a buildup of road salt ions in both soil and water bodies, altering their natural chemical composition. </p>
<p>These elevated salt concentrations can harm freshwater organisms and vegetation, change soil structure, and, when <a href="https://doi.org/10.1016/j.scitotenv.2023.166466">seeping into groundwater</a>, compromise the potable water supply of nearby communities.</p>
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<a href="https://theconversation.com/winter-road-salting-has-year-round-consequences-173621">Winter road salting has year-round consequences</a>
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<p><a href="https://doi.org/10.1016/j.scitotenv.2022.157336">Recent research</a> has shed light on a less conspicuous yet equally significant consequence of road salt usage: its contribution to oxygen depletion in lakes. The occurrence of <a href="https://doi.org/10.1029/2023JG007558">very low oxygen concentrations, or hypoxia, in a lake is generally attributed to an excessive input of nutrients, especially that of phosphorus</a>. </p>
<p>Nutrient enrichment can trigger algal blooms that, in turn, lower the oxygen level in the lake’s deeper waters. The continued expansion of hypoxic conditions deteriorates the lake’s water quality and may ultimately cause the die-off of most aquatic life. This nutrient-driven process, <a href="https://doi.org/10.5194/bg-14-3585-2017">known as eutrophication</a>, is affecting the ecological health of a growing number of lakes around the world.</p>
<h2>Salt and oxygen in water</h2>
<p><a href="https://doi.org/10.5194/egusphere-egu2020-16637">Phosphorus</a>, the nutrient frequently implicated in lake eutrophication, plays a multifaceted role in this scenario. <a href="https://doi.org/10.1016/j.scitotenv.2022.157336">Salinization</a> increases the density of the water reducing the mixing of the lake waters and. Consequently, this reduces the amount of oxygen that reaches the lake’s depths. </p>
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Read more:
<a href="https://theconversation.com/road-salt-makes-winter-driving-safer-but-what-does-it-do-to-the-environment-87860">Road salt makes winter driving safer, but what does it do to the environment?</a>
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<p>Oxygen depletion, paradoxically, favours the remobilization of phosphorus from the sediments accumulating at the bottom of the lake. That is, the sediments become an increasingly important <em>internal</em> source of phosphorus, escalating the nutrient enrichment of the lake. </p>
<p>In that way, salinization — driven by extensive road salt application — <a href="https://doi.org/10.1016/j.scitotenv.2022.157336">intensifies eutrophication symptoms</a> that are usually associated with phosphorus supplied to lakes from external sources in the surrounding landscape.</p>
<h2>Navigating the saline challenge</h2>
<p>Canada has been <a href="https://doi.org/10.1016/j.scitotenv.2021.151717">proactive in responding</a> to eutrophication. For instance, reduced phosphorus pollution in Lake Erie in the 1980s and 1990s led to significant <a href="https://doi.org/10.1029/2019WR025019">water quality improvements</a>. However, addressing accelerating salinization of lakes requires new thinking and innovative solutions that recognize the complexity of the issue. It’s not just de-icers, such as road salts, that need to be considered. </p>
<p><a href="https://doi.org/10.1098/rstb.2018.0019">Other sources of salt</a>, such as agricultural runoff, discharges from water softeners and other domestic activities and drainage from mine waste and geological salt deposits, are all part of the problem. Salinization is a <a href="https://doi.org/10.1073/pnas.1620211114">threat to water resources globally</a>, not just those of cold regions.</p>
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<figcaption><span class="caption">A brief overview of the process of eutrophication, produced by the National Oceanic and Atmospheric Administration.</span></figcaption>
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<p>Chloride, a key component of road salt, has earned the moniker of a “forever contaminant” <a href="https://doi.org/10.1016/j.scitotenv.2018.10.242">due to its persistence in soil and water systems</a>. When introduced into the environment, chloride ions readily dissolve into water <a href="https://doi.org/10.1016/j.scitotenv.2018.10.242">where they tend to remain</a>. </p>
<p>Over time, chloride not only accumulates in surface water bodies <a href="https://doi.org/10.1016/j.scitotenv.2023.166466">but also in groundwater</a>. In fact, ground (or subsurface) water has been identified as a persistent source of chloride to surface freshwater bodies, especially during the summer months. </p>
<p>While <a href="https://doi.org/10.2166/wqrjc.2011.105">proactive management practices have been introduced</a>, the accumulation of chloride and other problematic <a href="https://doi.org/10.1111/j.1747-6593.2012.00371.x">salt ions</a>, including sodium, in soil and water will require expensive and <a href="https://doi.org/10.2134/jeq2009.0108">time-consuming restoration efforts</a>. </p>
<h2>Paving the path to solutions</h2>
<p>To mitigate the impacts of salinization, evidence-based approaches are urgently required. Solutions and policy recommendations must promote the reduction of salt runoff from road salt applications and other sources, and establish effective and comprehensive monitoring programs. </p>
<p>We have much to learn from how we’ve successfully managed excessive nutrient pollution — these lessons can help inform salt management strategies that work hand in hand with water quality and climate change solutions.</p>
<p>One potential alternative to the application of road salts is to use other de-icers. This requires a cautious stance because, as history teaches us, replacing one troublesome chemical with another often comes with unexpected ecological consequences. </p>
<p>Thorough examination and research are vital to ensure that alternatives don’t inadvertently introduce new threats.</p>
<h2>Protecting people and ecosystems</h2>
<p>The stakes are high when it comes to road salts: compromised drinking water, shrinking aquatic habitats and long-term pollution from legacy salt stores in soil and groundwater requiring costly remediation. It’s imperative that research, investment and public awareness converge to address this challenge holistically. </p>
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Read more:
<a href="https://theconversation.com/to-make-less-harmful-road-salts-were-studying-natural-antifreezes-produced-by-fish-153087">To make less-harmful road salts, we're studying natural antifreezes produced by fish</a>
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<p>The impacts of road salt’s application extend far beyond the icy surfaces it’s intended to protect us from. As winter approaches, policy should work towards protecting our ecosystems and the many services they provide.</p><img src="https://counter.theconversation.com/content/215131/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jovana received support from the Natural Sciences and Engineering Research Council of Canada (NSERC) Strategic Partnerships Grant (STPGP 521515-18), and the Lake Futures project and Managing Urban Eutrophication Risks under Climate Change project within the Global Water Futures (GWF) program funded by the Canada First Research Excellence Fund (CFREF).</span></em></p><p class="fine-print"><em><span>David L Rudolph receives funding from the Natural Sciences and Engineering Research Council of Canada, the Ontario Ministry of the Environment, Conservation and Parks and the Regional Municipality of Waterloo. </span></em></p><p class="fine-print"><em><span>Fereidoun received support from the Natural Sciences and Engineering Research Council of Canada (NSERC) Strategic Partnerships Grant (STPGP 521515-18), and the Lake Futures project and Managing Urban Eutrophication Risks under Climate Change project within the Global Water Futures (GWF) program funded by the Canada First Research Excellence Fund (CFREF).</span></em></p><p class="fine-print"><em><span>Nancy received support from the Natural Sciences and Engineering Research Council of Canada (NSERC) Strategic Partnerships Grant (STPGP 521515-18), and the Lake Futures project and Managing Urban Eutrophication Risks under Climate Change project within the Global Water Futures (GWF) program funded by the Canada First Research Excellence Fund (CFREF).</span></em></p><p class="fine-print"><em><span>Philippe received support from the Natural Sciences and Engineering Research Council of Canada (NSERC) Strategic Partnerships Grant (STPGP 521515-18), and the Lake Futures project and Managing Urban Eutrophication Risks under Climate Change project within the Global Water Futures (GWF) program funded by the Canada First Research Excellence Fund (CFREF).</span></em></p><p class="fine-print"><em><span>Jiangyue Ju does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Increasing awareness of the dangers ‘forever chemical’ road salts pose to our fresh water systems highlights the urgent importance of finding new approaches to de-icing our roads.Jovana Radosavljevic, Postdoctoral Fellow, Ecohydrology Research Group, University of WaterlooDavid L Rudolph, Professor of Hydrogeology, Department of Earth & Environmental Sciences, University of WaterlooFereidoun Rezanezhad, Research Associate Professor, Department of Earth & Environmental Sciences, University of WaterlooJiangyue Ju, PhD Student in Earth and Environmental Sciences, University of WaterlooNancy Goucher, Knowledge Mobilization Specialist, University of WaterlooPhilippe Van Cappellen, Professor of Biogeochemistry and Canada Excellence Research Chair Laureate in Ecohydrology, University of WaterlooLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1834182022-06-14T12:30:35Z2022-06-14T12:30:35ZFertilizer prices are soaring – and that’s an opportunity to promote more sustainable ways of growing crops<figure><img src="https://images.theconversation.com/files/468526/original/file-20220613-11-9yinfb.jpg?ixlib=rb-1.1.0&rect=14%2C0%2C4905%2C3275&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A farmer spreads fertilizer on a field in Berks County, Pa.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/farmer-spreads-fertilizer-on-his-field-on-a-saturday-night-news-photo/1315197588">Harold Hoch/MediaNews Group/Reading Eagle via Getty Images</a></span></figcaption></figure><p>Farmers are coping with a <a href="https://www.fb.org/market-intel/too-many-to-count-factors-driving-fertilizer-prices-higher-and-higher">fertilizer crisis</a> brought on by soaring fossil fuel prices and industry consolidation. The price of synthetic fertilizer has more than <a href="https://www.agweb.com/news/crops/crop-production/fertilizer-prices-just-fell-30-one-day-farmers-saw-prices-skyrocket-133">doubled</a> since 2021, causing great stress in farm country. </p>
<p>This crunch is particularly tough on those who grow corn, which accounts for half of U.S. nitrogen fertilizer use. The National Corn Growers Association predicts that its members will <a href="https://www.regulations.gov/comment/AMS-AMS-22-0027-1349">spend 80% more in 2022 on synthetic fertilizers</a> than they did in 2021. A recent study estimates that on average, this will represent <a href="https://dt176nijwh14e.cloudfront.net/file/481/Study%20.pdf">US$128,000 in added costs per farm</a>.</p>
<p>In response, the Biden administration <a href="https://www.usda.gov/media/press-releases/2022/03/11/usda-announces-plans-250-million-investment-support-innovative">announced a new grant program</a> on March 11, 2022, “to support innovative American-made fertilizer to give U.S. farmers more choices in the marketplace.” The U.S. Department of Agriculture will invest <a href="https://www.dtnpf.com/agriculture/web/ag/news/business-inputs/article/2022/05/11/usda-aid-precision-ag-fertilizer">$500 million</a> to try to lower fertilizer costs by increasing production. But since this probably isn’t enough money to construct new fertilizer plants, it’s not clear how the money will be spent.</p>
<p>I direct the <a href="https://sustainability-innovation.asu.edu/food/">Swette Center for Sustainable Food Systems</a> at Arizona State University and have held senior positions at the USDA, including serving as deputy secretary of agriculture from 2009 to 2013. In my view, producing more synthetic fertilizer should not be the only answer to this serious challenge. The U.S. should also provide support for nature-based solutions, including farming practices that help farmers reduce or forgo synthetic fertilizers, and biological products that substitute for harsher chemical inputs.</p>
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<figcaption><span class="caption">Peas, beans and clover add nitrogen to soil naturally and can supplement or substitute for synthetic nitrogen fertilizer.</span></figcaption>
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<h2>Too much fertilizer in the wrong places</h2>
<p>All plants need nutrients to grow, especially the “big three” macronutrients: <a href="https://www.bhg.com/gardening/yard/garden-care/what-do-nitrogen-phosphorus-and-potassium-do/">nitrogen, phosphorus and potassium</a>. Farmers can fertilize their fields by planting <a href="https://tilthalliance.org/resources/how-legumes-fix-nitrogen-in-your-soil/">crops that add nitrogen to soil naturally</a> or by applying animal manure and compost to soil. </p>
<p>Since World War II, however, farmers have relied mainly on manufactured synthetic fertilizers that contain various ratios of nitrogen, phosphorus and potassium, along with secondary nutrients and micronutrients. That shift happened because manufacturers produced huge quantities of ammonium nitrate, the main ingredient in explosives, during the war; when the conflict ended, they <a href="https://cropwatch.unl.edu/fertilizer-history-p3">switched to making nitrogen fertilizer</a>.</p>
<p>Synthetic fertilizers have greatly enhanced crop yields and are rightly credited with <a href="https://www.unep.org/news-and-stories/story/fertilizers-challenges-and-solutions">helping to feed the world</a>. But they <a href="https://ourworldindata.org/reducing-fertilizer-use">aren’t used evenly around the world</a>. In poor regions like sub-Saharan Africa, too little fertilizer is available. In wealthier areas, abundant synthetic fertilizers have contributed to overapplication and serious <a href="https://theconversation.com/a-few-heavy-storms-cause-a-big-chunk-of-nitrogen-pollution-from-midwest-farms-146980">environmental harm</a>. </p>
<p>Excess fertilizer washes off of fields during storms and runs into rivers and lakes. There, it fertilizes huge blooms of algae that die and decompose, depleting oxygen in the water and creating “dead zones” that can’t support fish or other aquatic life. This process, <a href="https://oceanservice.noaa.gov/facts/eutrophication.html">eutrophication</a>, is a major problem in the <a href="https://www.canr.msu.edu/news/on_the_re_eutrophication_of_lake_erie">Great Lakes</a>, the <a href="https://mde.maryland.gov/programs/water/TMDL/TMDLImplementation/Pages/overview.aspx">Chesapeake Bay</a>, the <a href="https://www.noaa.gov/news-release/larger-than-average-gulf-of-mexico-dead-zone-measured">Gulf of Mexico</a> and <a href="https://www.usgs.gov/mission-areas/water-resources/science/nutrients-and-eutrophication">many other U.S. water bodies</a>. </p>
<p>Excess nitrogen can also contaminate drinking water and <a href="https://www.dhs.wisconsin.gov/publications/p02559.pdf">threaten human health</a>. And fertilizers, whether animal-sourced or synthetic, are a significant source of <a href="https://doi.org/10.1038/s41586-020-2780-0">nitrous oxide</a>, a potent greenhouse gas. </p>
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<span class="caption">Heavy nutrient runoff from farmlands produces chronic blooms of algae in Lake Erie, the smallest Great Lake by volume.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/ejuTfh">NOAA</a></span>
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<h2>What’s causing the crisis</h2>
<p>One reason U.S. fertilizer prices have spiked is that farmers are beholden to imports. COVID-19 disrupted supply chains, especially from China, a major fertilizer producer. And the war in Ukraine has cut off access to <a href="https://www.cropnutrition.com/resource-library/what-is-potash">potash</a>, an important potassium source, from Russia and Belarus. </p>
<p>Another factor is that the fertilizer industry is <a href="https://www.g20-insights.org/policy_briefs/promoting-competition-in-the-fertilizer-industry-and-efficiency-in-the-fertilizer-use-to-improve-land-productivity-and-sustainability/#_ftn4">highly concentrated</a>. There is little competition, so farmers have no choice but to buy fertilizer at the market price. Several U.S. state attorneys general have called on economists to study <a href="https://www.agweb.com/news/crops/crop-production/usda-attorney-generals-call-economists-study-soaring-fertilizer-costs">anti-competitive practices in the fertilizer industry</a>.</p>
<p>The USDA is seeking information on <a href="https://www.regulations.gov/document/AMS-AMS-22-0027-0001">competition and supply chain concerns in fertilizer markets</a> with a public comment deadline of June 15, 2022. But out of 66 specific questions the department posed with this request, only one addresses what I believe is the key issue: “How might USDA better support modes of production that rely less on fertilizer, or support access to markets that may pay a premium for products relying on less fertilizer?”</p>
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<h2>Rethinking how to grow crops</h2>
<p>I see an opportunity for the Biden administration to take a fresh look at biological products as substitutes for synthetic fertilizers. This category includes <a href="https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/biofertilizer">biofertilizers and bionutrients</a> – natural materials that provide crop nutrition. Examples include microorganisms that extract nitrogen from the air and convert it into forms that plants can use, and fertilizers converted from manure, food and other plant and wood wastes. </p>
<p>Another category, <a href="https://www.bpia.org/solutions-provided-by-biological-products-biostimulants/">biostimulants</a>, comprises natural materials that enhance uptake of plant nutrients, reduce crop stress and increase crop growth and quality. Examples include algae and other plant extracts, microorganisms and <a href="https://soilbiotics.com/files/Humic_Acid_Explained.pdf">humic acids</a> – complex molecules produced naturally in soil when organic material breaks down.</p>
<p>In the past, critics dismissed natural products like these as “<a href="https://www.farmprogress.com/management/beware-snake-oil-fertilizers">snake oil</a>,” with little scientific evidence to show that they worked. Now, however, most experts believe that while <a href="https://doi.org/10.3389/fsufs.2021.606815">much remains to be learned</a>, current biofertilizers “offer huge potential in terms of <a href="https://doi.org/10.3389/fpls.2018.01473">new and more sustainable crop management practices</a>.” </p>
<p>Studies have demonstrated many benefits from these products. They include <a href="https://doi.org/10.3389/fmicb.2018.01606">less need for fertilizer</a>, <a href="https://doi.org/10.1007/s11104-014-2131-8">larger crop yields</a>, <a href="https://ucanr.edu/sites/CEStanislausCo/files/319748.pdf">enhanced soil health</a> and <a href="https://doi.org/10.1016/j.scitotenv.2021.148913">fewer carbon emissions</a>. </p>
<p>Large synthetic fertilizer companies like <a href="https://www.agweb.com/news/crops/crop-production/mosaic-eyes-expansion-biological-products">Mosaic</a>, <a href="https://www.ocpgroup.ma/press-release/ocp-sa-and-fertinagro-biotech-sl-announce-establishment-joint-venture-jorf-lasfar">OCP</a> and Nutrien are distributing, acquiring or investing in these biological technologies. Agribusiness giant Bayer has <a href="https://www.wired.com/story/farmers-can-now-buy-designer-microbes-to-replace-fertilizer/">partnered with Ginkgo Bioworks</a> in a joint venture called <a href="https://joynbio.com/about">Joyn</a> whose mission is creating “sustainable ag biologicals for crop protection and fertility that meet or exceed the performance of their chemical counterparts.”</p>
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<a href="https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&rect=50%2C0%2C5568%2C3709&q=45&auto=format&w=1000&fit=clip"><img alt="A hand spreads pellets and crushed rock over dirt." src="https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&rect=50%2C0%2C5568%2C3709&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/468496/original/file-20220613-16-b1t9iz.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">A farmer spreads two types of organic fertilizers – bone meal pellets and rock phosphate – before planting spinach in Golden, Colo.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/david-wann-spreads-organic-fertilizers-bone-meal-pellets-news-photo/649873342">Joe Amon/The Denver Post via Getty Images</a></span>
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<h2>Offering more choices</h2>
<p>Panicked U.S. farmers facing daunting fertilizer prices are looking for options. In public comments on USDA’s fertilizer initiative, the <a href="https://www.regulations.gov/comment/AMS-AMS-22-0027-1064">Illinois Corn Growers Association</a> urged the department to investigate why farmers apply fertilizers at levels higher than necessary, while others noted a shortage of agronomists sufficiently trained to guide farmers on how best to sustainably fertilize their crops. </p>
<p>I believe now is an opportune time for USDA to offer incentives for adopting biologicals, as well as practices that organic farmers use to replace synthetic fertilizers, such as <a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/national/programs/?cid=nrcs142p2_044349">crop rotation</a>, <a href="http://cwmi.css.cornell.edu/composting.htm">composting</a> and <a href="https://www.csuchico.edu/regenerativeagriculture/ra101-section/integrating-livestock.shtml">raising crops and livestock together</a>. A first step would be to deploy technicians who can advise farmers about sustainable practices and biological products. The department recently announced a new $300 million initiative to <a href="https://www.usda.gov/media/press-releases/2022/06/01/usda-announces-framework-shoring-food-supply-chain-and-transforming">help farmers transition to organic production</a>; this is the right idea, but more help is needed. </p>
<p>The agency could also provide one-time payments to farmers in exchange for reducing their use of synthetic fertilizers, which would help to compensate them as they shift their production methods. In the longer term, I believe the USDA should develop new crop insurance tools to protect farmers from the risks of transitioning to more sustainable options. In my view, this kind of broad response would yield more value than a taxpayer-funded, status quo approach to synthetic fertilizers.</p><img src="https://counter.theconversation.com/content/183418/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kathleen Merrigan worked for six years at the US Department of Agriculture, most recently serving as Deputy Secretary of Agriculture from 2009-2013. She is a venture partner at Astanor Ventures, a European-based agtech firm that invests in a wide range of innovations, including in the biocontrol/biostiumulant sector. She previously served on the board of directors of Marrone Bio Innovations and holds stock in the company. </span></em></p>Farmers are contending with huge spikes in fertilizer prices. The Biden administration is paying US companies to boost synthetic fertilizer production, but there are other, more sustainable options.Kathleen Merrigan, Executive Director, Swette Center for Sustainable Food Systems, Arizona State UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1810372022-05-19T12:23:07Z2022-05-19T12:23:07ZRestoring the Great Lakes: After 50 years of US-Canada joint efforts, some success and lots of unfinished business<figure><img src="https://images.theconversation.com/files/464009/original/file-20220518-11-qy3i71.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4000%2C2311&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Children participate in a water fight in Lake Ontario in Mississauga, Ontario, during a heat wave on June 5, 2021. </span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/children-have-a-water-fight-at-lake-ontario-in-mississauga-news-photo/1233295324">Zou Zheng/Xinhua via Getty Images</a></span></figcaption></figure><p>The Great Lakes cover <a href="https://theconversation.com/the-impulse-to-garden-in-hard-times-has-deep-roots-137223">nearly 95,000 square miles</a> (250,000 square kilometers) and hold over 20% of Earth’s surface fresh water. <a href="https://coast.noaa.gov/states/fast-facts/great-lakes.html">More than 30 million people</a> in the U.S. and Canada rely on them for drinking water. The lakes support a multibillion-dollar maritime economy, and the lands around them provided many of the raw materials – timber, coal, iron – that fueled the Midwest’s emergence as an industrial heartland.</p>
<p>Despite their enormous importance, the lakes were <a href="https://www.ijc.org/en/great-lakes-1972-water-quality-agreement">degraded for well over a century</a> as industry and development expanded around them. By the 1960s, rivers like the Cuyahoga, Buffalo and Chicago were so polluted that they were <a href="https://www.environmentalcouncil.org/when_our_rivers_caught_fire">catching fire</a>. In 1965, Maclean’s magazine called Lake Erie, the smallest and shallowest Great Lake, “<a href="https://archive.macleans.ca/article/1965/11/1/death-of-a-great-lake">an odorous, slime-covered graveyard</a>” that “may have already passed the point of no return.” Lake Ontario <a href="https://scholar.uwindsor.ca/cgi/viewcontent.cgi?article=1012&context=ijcarchive">wasn’t far behind</a>.</p>
<p>In 1972, the U.S. and Canada signed the <a href="https://www.ijc.org/sites/default/files/C23.pdf">Great Lakes Water Quality Agreement</a>, a landmark pact to clean up the Great Lakes. Now, 50 years later, they have made progress, but there are new challenges and much unfinished business. </p>
<p>I <a href="https://scholar.google.com/citations?user=G4RniBIAAAAJ&hl=en">study the environment</a> and have written four books on U.S.-Canadian management of their shared border waters. In my view, the Great Lakes Water Quality Agreement was a watershed moment for environmental protection and an international model for regulating transboundary pollution. But I believe the people of the U.S. and Canada failed the Great Lakes by becoming complacent too soon after the pact’s early success. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Map of the Great Lakes-St. Lawrence Basin" src="https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=443&fit=crop&dpr=1 600w, https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=443&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=443&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=557&fit=crop&dpr=1 754w, https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=557&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/463989/original/file-20220518-15-6nn6jw.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=557&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The Great Lakes-St Lawrence River Basin spans nearly half of North America, from northern Minnesota to New England.</span>
<span class="attribution"><a class="source" href="https://www.ijc.org/en/watersheds/great-lakes">International Joint Commission</a></span>
</figcaption>
</figure>
<h2>Starting with phosphates</h2>
<p>A major step in Canada-U.S. joint management of the Great Lakes came in 1909 when they signed the <a href="https://www.ijc.org/en/boundary-waters-treaty-1909">Boundary Waters Treaty</a>. The Great Lakes Water Quality Agreement built on this foundation by creating a framework to allow the two countries to cooperatively restore and protect these border waters. </p>
<p>However, as an executive agreement, rather than a formal government-to-government treaty, the pact has no legal mechanisms for enforcement. Instead, it relies on the U.S. and Canada to fulfill their commitments. The <a href="https://www.ijc.org/en/who/role">International Joint Commission</a>, an agency created under the Boundary Waters Treaty, carries out the agreement and tracks progress toward its goals. </p>
<p>The agreement set common targets for controlling a variety of pollutants in Lake Erie, Lake Ontario and the upper St. Lawrence River, which were the most polluted section of the Great Lakes system. One key aim was to reduce nutrient pollution, especially phosphates from detergents and sewage. These chemicals fueled huge blooms of algae that then died and decomposed, depleting oxygen in the water. </p>
<p>Like national water pollution laws enacted at the time, these efforts focused on point sources – pollutants released from discreet, readily identifiable points, such as discharge pipes or wells.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Diagram of the Great Lakes and connecting water bodies in profile." src="https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=250&fit=crop&dpr=1 600w, https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=250&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=250&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=314&fit=crop&dpr=1 754w, https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=314&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/463987/original/file-20220518-20-uyapnj.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=314&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">This profile view of the Great Lakes shows that Lake Erie is much shallower than the other lakes. As a result, its waters warm faster and are more vulnerable to algal blooms.</span>
<span class="attribution"><a class="source" href="https://twitter.com/NOAA_GLERL/status/1270022370640658437/photo/1">NOAA</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Early results were encouraging. Both governments invested in new sewage treatment facilities and convinced manufacturers to <a href="https://www.nytimes.com/1970/05/03/archives/detergents-listed-in-phosphate-order.html">reduce phosphate loads in detergents and soaps</a>. But as phosphorus levels in the lakes declined, scientists soon detected other problems.</p>
<h2>Toxic contaminants</h2>
<p>In 1973, scientists reported a perplexing find in fish from Lake Ontario: <a href="http://dx.doi.org/%2010.1126/science.185.4150.523">mirex, a highly toxic organochloride pesticide</a> used mainly to kill ants in the southeast U.S. An investigation revealed that the <a href="https://www.nytimes.com/1976/09/03/archives/new-jersey-pages-chemical-flowing-illegally-into-niagara-toxic.html">Hooker Chemical company</a> was discharging mirex from its plant in Niagara Falls, New York. The contamination was so severe that New York State <a href="https://aliciapatterson.org/stories/northern-fish-mystery">banned eating popular types of fish</a> such as coho salmon and lake trout from Lake Ontario from 1976 to 1978, shutting down commercial and sport fishing in the lake. </p>
<p>In response to this and other findings, the U.S. and Canada updated the Great Lakes Water Quality Agreement in 1978 to cover all five lakes and focus on chemicals and toxic substances. This version formally adopted an <a href="https://ijc.org/sites/default/files/2019-05/WQB_PracticalStepstoImplementanEcosystemApproachinGreatLakesManagement_December1995.pdf">ecosystem approach</a> to pollution control that considered interactions between water, air and land – perhaps the first international agreement to do so. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/gBRcOLcEwF0?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">A tour of the Great Lakes and the nature in and around them.</span></figcaption>
</figure>
<p>In 1987, the two countries identified <a href="https://www.ijc.org/en/what/glwq-aoc">the most toxic hot spots</a> around the lakes and adopted action plans to clean them up. However, as <a href="https://press.ucalgary.ca/books/9781552388952/">scholars</a> of North American environmental regulations <a href="https://press.uchicago.edu/ucp/books/book/chicago/M/bo3629140.html">acknowledge</a>, both nations too often allowed industries to police themselves. </p>
<p>Since the 1990s, <a href="https://www.dec.ny.gov/data/DecDocs/932121/Report.HW.932121.2009-03-26.ToxicsChemicalsInTributariesToLakeOntario.pdf">studies</a> have identified toxic pollutants including <a href="https://doi.org/10.1021/acs.estlett.8b00019">PCBs</a>, <a href="https://doi.org/10.1016/j.envint.2020.106065">DDT</a> and chlordane in and around the Great Lakes, as well as lead, copper, arsenic and others. Some of these chemicals <a href="https://doi.org/10.1021/es501509r">continued to show up</a> because they were persistent and took a long time to break down. Others were banned but leached from contaminated sites and sediments. Still others came from a range of point and nonpoint sources, including <a href="https://www.ijc.org/sites/default/files/D9.pdf">many industrial sites</a> concentrated on shorelines.</p>
<p>Many hazardous sites have been slowly cleaned up. However, toxic pollution in the Great Lakes <a href="https://www.regions.noaa.gov/great-lakes/index.php/great_lakes-restoration-initiative/toxics/">remains a colossal problem</a> that is largely unappreciated by the public, since these substances don’t always make the water look or smell foul. Numerous <a href="https://ehp.niehs.nih.gov/doi/10.1289/ehp104">fish advisories</a> are still in effect across the region because of chemical contamination. Industries constantly bring new chemicals to market, and <a href="https://www.pbs.org/newshour/science/it-could-take-centuries-for-epa-to-test-all-the-unregulated-chemicals-under-a-new-landmark-bill">regulations lag far behind</a>.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1004722065247698944"}"></div></p>
<h2>Nonpoint sources</h2>
<p>Another major challenge is <a href="https://www.epa.gov/nps/basic-information-about-nonpoint-source-nps-pollution">nonpoint source pollution</a> – discharges that come from many diffuse sources, such as runoff from farm fields. </p>
<p><a href="https://doi.org/10.1086/684646">Nitrogen levels</a> in the lakes have risen significantly because of agriculture. Like phosphorus, nitrogen is a nutrient that causes large blooms of algae in fresh water; it is one of the main ingredients in fertilizer, and is also found in human and animal waste. <a href="https://greatlakes.org/campaigns/sewage-overflows/">Sewage overflows</a> from cities and <a href="https://elpc.org/blog/the-great-lakes-cafos-and-water-quality/">waste and manure runoff</a> from industrial agriculture carry heavy loads of nitrogen into the lakes.</p>
<p>As a result, algal blooms have <a href="https://www.glerl.noaa.gov/res/HABs_and_Hypoxia/bulletin.html">returned to Lake Erie</a>. In 2014, toxins in one of those blooms forced officials in Toledo, Ohio, to <a href="https://greatlakes.org/2019/08/five-years-later-lessons-from-the-toledo-water-crisis/">shut off the public water supply</a> for half a million people. </p>
<p>One way to address nonpoint source pollution is to set an overall limit for releases of the problem pollutant into local water bodies and then work to bring discharges down to that level. These measures, known as <a href="https://www.epa.gov/tmdl/overview-total-maximum-daily-loads-tmdls">Total Maximum Daily Loads</a>, have been applied or are in development for parts of the Great Lakes basin, including <a href="https://greatlakes.org/2020/02/statement-development-of-a-pollution-diet-for-western-lake-erie/">western Lake Erie</a>.</p>
<p>But this strategy relies on states, along with <a href="https://www.freshlawblog.com/2016/06/02/us-epas-great-lakes-restoration-initiative-grants-for-voluntary-action-a-striking-contrast-to-the-chesapeake-bay-tmdl/">voluntary steps by farmers</a>, to curb pollution releases. Some Midwesterners would prefer a regional approach like the strategy for Chesapeake Bay, where states asked the U.S. government to write a sweeping <a href="https://www.chesapeakebay.net/what/programs/total_maximum_daily_load">federal TMDL for key pollutants</a> for the bay’s entire watershed.</p>
<p>In 2019, Toledo voters adopted a <a href="https://theconversation.com/how-giving-legal-rights-to-nature-could-help-reduce-toxic-algae-blooms-in-lake-erie-115351">Lake Erie Bill of Rights</a> that would have permitted citizens to sue when Lake Erie was being polluted. Farmers <a href="https://www.michiganradio.org/environment-science/2020-02-28/lake-erie-bill-of-rights-declared-unconstitutional">challenged the measure in court</a>, and it was declared unconstitutional.</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/CdmlEGTMwkA/?utm_source=ig_web_copy_link","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<h2>Warming and flooding</h2>
<p><a href="https://nca2018.globalchange.gov/chapter/21/">Climate change</a> is now complicating Great Lakes cleanup efforts. Warmer water can affect oxygen concentrations, nutrient cycling and food webs in the lakes, potentially <a href="https://theconversation.com/warmer-wetter-wilder-38-million-people-in-the-great-lakes-region-are-threatened-by-climate-change-170195">intensifying problems</a> and converting nuisances into major challenges. </p>
<p>Flooding driven by climate change threatens to <a href="https://theconversation.com/climate-change-threatens-drinking-water-quality-across-the-great-lakes-131883">contaminate public water supplies</a> around the lakes. Record-high water levels are <a href="https://theconversation.com/great-lakes-flooding-the-warning-signs-that-homes-must-be-moved-122697">eroding shorelines and wrecking infrastructure</a>. And new problems are emerging, including <a href="https://www.greatlakesnow.org/2021/05/chemical-impact-microplastic-pollution/">microplastic pollution</a> and “forever chemicals” such as <a href="https://news.wisc.edu/study-finds-tributaries-play-significant-role-in-great-lakes-pfas-loading/">PFAS and PFOA</a>. </p>
<p>It will be challenging for the U.S. and Canada to make progress on this complex set of problems. Key steps include prioritizing and funding cleanup of toxic zones, finding ways to halt agricultural runoff and building new sewer and stormwater infrastructure. If the two countries can muster the will to aggressively tackle pollution problems, as they did with phosphates in the 1970s, the Great Lakes Water Quality Agreement gives them a framework for action.</p><img src="https://counter.theconversation.com/content/181037/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Daniel Macfarlane has received funding from the Social Sciences and Humanities Research Council and Western Michigan University. </span></em></p>Cleaning up the Great Lakes was a big job when the US and Canada undertook it in 1972. Today it’s far more challenging.Daniel Macfarlane, Associate Professor of Environment and Sustainability, Western Michigan UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1599632021-05-09T18:09:36Z2021-05-09T18:09:36ZInterdisciplinary approaches to coastal vulnerability: the pathway to coastal sustainability<figure><img src="https://images.theconversation.com/files/397606/original/file-20210428-17-krn75i.png?ixlib=rb-1.1.0&rect=0%2C2%2C1500%2C837&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Coastal areas in West Africa are under intense pressure from demographic growth, economic expansion and ongoing climate change.</span> <span class="attribution"><span class="source">IRD</span>, <span class="license">Author provided</span></span></figcaption></figure><p>Around the world, fragile coastal ecosystems are under intense pressure from unrelenting human activity, gradual yet relentless climate trends and extreme weather events. Understanding and managing their complex and sometimes catastrophic interactions requires an integrated and interdisciplinary approach. In this article, we articulate the plausible future reciprocal relationship between the natural and social subsystems within the coastal systems and how to manage these changes via adaptive and inclusive approaches.</p>
<p>Using a <a href="https://esajournals.onlinelibrary.wiley.com/doi/10.1890/100068">press-pulse dynamics conceptual framework</a>, we build in variables such as population growth, economic development, governance quality, technological change, and infrastructural development. The result is three future scenarios for coastal areas undergoing major ecosystem structures and functions alterations.</p>
<ul>
<li><p>Anthropocentric: Under this human-centred scenario, current trends continue along the coast, with rising population, economic activities and infrastructural development, and weak governance and poor policy implementation.</p></li>
<li><p>Anthro-ecocentric: This scenario is characterised by increasing population, infrastructural and economic development, significant advancement in technology, but also a modest improvement in environmental quality as a result of good governance.</p></li>
<li><p>Ecocentric: This environment-centred scenario is characterised by government incentives for conservation, green energy, and land-use planning.</p></li>
</ul>
<p>The three scenarios are all based on the worst-case climatic conditions for the future as predicted by the <a href="https://www.ipcc.ch/srocc/chapter/chapter-4-sea-level-rise-and-implications-for-low-lying-islands-coasts-and-communities/">IPCC report</a>, RCP 8.5.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/397611/original/file-20210428-23-5j1zlt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397611/original/file-20210428-23-5j1zlt.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397611/original/file-20210428-23-5j1zlt.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397611/original/file-20210428-23-5j1zlt.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397611/original/file-20210428-23-5j1zlt.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397611/original/file-20210428-23-5j1zlt.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397611/original/file-20210428-23-5j1zlt.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Saint Louis coast, Senegal.</span>
<span class="attribution"><span class="source">IRD</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<h2>Our findings</h2>
<p>We applied our conceptual model to West Africa coastal areas. Currently, strong economic activities and urbanisation cluster along the coastline, generating multifaceted pressures on resources, acute tensions among users, ecosystems and marine resources degradation and the vulnerability of coastal areas. Coastal degradation manifests by way of fisheries depletion, pollution, flooding and coastal erosion.</p>
<p><em>1. “Anthropocentric” scenario</em></p>
<p>Here, current trends continue along the coast, with rising population, economic activities and infrastructural development, and weak governance and poor policy implementation. Major developments like new ports development and expansion, resource exploitation, unregulated groundwater extraction, urban expansion, upriver damming, and other projects, are implemented without environmental and social impact assessment.</p>
<p>Under this scenario, there would be a huge decline in the key ecological goods and services functions. Continuing exploitation of coastal resources leads to floods and aggravated coastal erosion, the greater vulnerability of floras and faunas, and the degradation and destruction of their habitats. Without adaptation, sea level rise (SLR) and more intense and frequent extreme sea-level events, combined with trends in coastal development amplify expected annual flood damages.</p>
<p>Coastal protection systems in urban cities and densely populated regions would reduce expected damages and be relatively cost-efficient, but would be unaffordable for rural and poorer areas, leaving them vulnerable. Coastal processes and associated land-use changes would be “business as usual”, creating a high risk of and vulnerability to flooding, erosion and pollution for poor and unprotected populations.</p>
<figure class="align-center ">
<img alt="Langue de Barbarie in Senegal" src="https://images.theconversation.com/files/397612/original/file-20210428-15-qou1o2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/397612/original/file-20210428-15-qou1o2.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/397612/original/file-20210428-15-qou1o2.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/397612/original/file-20210428-15-qou1o2.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/397612/original/file-20210428-15-qou1o2.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/397612/original/file-20210428-15-qou1o2.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/397612/original/file-20210428-15-qou1o2.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Along the Langue de Barbarie in Senegal, more than 800 m of shoreline have been lost in 10 years.</span>
<span class="attribution"><span class="source">IRD</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p><em>2. “Anthro-ecocentric” scenario</em></p>
<p>The global context for this scenario would be the same as the previous one. Here, the general approach to ecosystem services is reactive rather than proactive. Coastal-protection structures like sea walls, surge barriers and embankments are widespread, providing safety in many West African coastal cities and deltas. While these structures protect economic development, they will have a negative impact on economic interests and human health and well-being that rely on ecological goods. These include ecotourism, recreation and fisheries, clean air and fresh water. Also negatively affected are ecological services such as air and water purification, biodiversity maintenance, waste decomposition, soil and vegetation generation and renewal, groundwater recharge, greenhouse gas mitigation, and aesthetically landscapes.</p>
<p>Under this scenario, coastal-protection structures are prioritised in areas with higher socioeconomic values. Poorer areas with lower socioeconomic values receive less protection, leading to inequality, and this could increase political and social tensions. As sea levels continue to rise, the height of coastal-protection structures is increased, yet this may ultimately prove to be unaffordable and ineffective. Even with well-designed structures, the risk of possibly catastrophic effects in the event of their failure cannot be ruled out.</p>
<p>While hard structures along the coast may serve to protect urban areas, they can result in a significantly larger proportion of the ecosystems being lost. This may in turn leave communities vulnerable to adverse events such as floods, ocean surges, pollution, coastal eutrophication and saline intrusion. In the context of ongoing climate change, some of these may surpass a crucial threshold, overwhelming social capacity, and, consequently, affect human well-being.</p>
<p><em>3. “Ecocentric” coastal scenario</em></p>
<p>Under this environmentally focused scenario, government efforts are focused on encouraging environmental conservation, green energy, and effective land-use planning. Ecosystem-based policies are strengthened, ecotourism principles are supported, and environmental laws and regulations are enacted and adhered to. More confidence is placed on the development of environmental engineering, climate and energy-friendly technology, and new ways of farming that incorporate provisioning with regulating and cultural ecosystem services. The pace of population growth and economic development is wholly determined by environmental quality.</p>
<p>As with the prior scenarios, there will be sea-level rise driven by climate change, with the storms and extreme wave events that can increase coastal hazards. However, because the natural coastal systems are not passive, there are numerous threshold effects – they respond by adapting to the new configurations. Further, restoration of coastal ecosystems such as mangroves or tidal marshes – coastal “blue carbon” ecosystems – provide climate-change mitigation through increased carbon uptake and storage of around 0.5% of current global emissions annually.</p>
<p>Under this scenario, improved technology enhances the development of marine (blue) renewable energy production, green shipping and the protection of carbon-rich coastal ecosystems.</p>
<p>In light of the co-benefits for marine biodiversity and coastal livelihoods, the development of nature-based solutions in the coastal and marine environment can be seen as such no-regret option that should be given a high priority.</p>
<h2>The way forward</h2>
<p>What is the way forward for West African coastal areas? The upcoming IRD-UCC-World Bank policy brief couldn’t be clearer:</p>
<blockquote>
<p>“Good coastal risk management for the protection and development of the human, economic and natural stakes of the coastal zones should be decided and implemented in a concerted way between the actors of the territory and coherent with the objectives of the already existing territorial public policies. Besides, the use of local knowledge of the communities, interdisciplinary scientific studies and the operational know-how of technician will promote the acceptability, efficiency and sustainability of the management solutions envisaged. Finally, a global, systemic approach to coastal management should be employed.”</p>
</blockquote>
<p>This argues for a forward-looking, environmentally focused approach for managing our fragile coastal ecosystems. As indicated by our research, this approach has the greatest potential for achieving coastal sustainability.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/uLc9ozH1hf8?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Coastal erosion seen from space (IRD).</span></figcaption>
</figure><img src="https://counter.theconversation.com/content/159963/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Frédéric Ménard has received funding from the ANR, the Ministry of Ecological Transition, the FRB, the EU, the FFEM, the Ciência Sem Fronteiras program of the CNPq and the CAPES of Brazil.</span></em></p><p class="fine-print"><em><span>Pierre Morand est membre de l'Association Francaise d'Halieutique (science/recherche) et de l'African Bird Club (Ornithologie)
.
Il a reçu des financements de Agence Française de Développement, U.E., ENABEL, UEMOA, Banque Mondiale (WACA)</span></em></p><p class="fine-print"><em><span>Olusegun Dada et Rafael Almar ne travaillent pas, ne conseillent pas, ne possèdent pas de parts, ne reçoivent pas de fonds d'une organisation qui pourrait tirer profit de cet article, et n'ont déclaré aucune autre affiliation que leur poste universitaire.</span></em></p>Around the world, fragile coastal ecosystems are under intense pressure, and understanding and managing their complex interactions requires an integrated and interdisciplinary approach.Olusegun Dada, Senior postdoctoral research fellow, Institut de recherche pour le développement (IRD)Frédéric Ménard, Directeur de recherche, Institut de recherche pour le développement (IRD)Pierre Morand, Biostatisticien, Institut de recherche pour le développement (IRD)Rafael Almar, Chercheur en dynamique littorale, Institut de recherche pour le développement (IRD)Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1324072020-04-09T15:28:44Z2020-04-09T15:28:44ZWhy China is emerging as a leader in sustainable and organic agriculture<figure><img src="https://images.theconversation.com/files/326176/original/file-20200407-85423-tnhcgw.jpg?ixlib=rb-1.1.0&rect=89%2C107%2C5712%2C3781&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An increasing number of farmers in China are cutting back on fertilizer and pesticide use.</span> <span class="attribution"><span class="source">(Pexels)</span></span></figcaption></figure><p>It’s August and 38C outside a greenhouse on a fruit farm in suburban Nanjing, China. Inside the farmhouse, customers sample organic grapes and peaches. </p>
<p>Ms. Wang, who owns the farm, carefully lifts the cover off a large bin of earthworms. She is raising thousands of them to produce organic fertilizer for her farm. </p>
<p>Wang is one of an <a href="https://uwaterloo.ca/ecological-agriculture-in-china/our-fieldwork-and-fieldwork-photos/fieldwork-cases">increasing number farmers in China</a> who are cutting back on fertilizer and pesticide use, and tapping into consumer demand for organic and sustainably grown food. </p>
<p>China’s total grain output has almost quadrupled since 1961, when the great famine ended. But its success has come at a heavy environmental cost: <a href="https://www.coventry.ac.uk/globalassets/media/documents/research-documents/coventry-china-agriculture-aw-new-style.pdf">China uses four times more fertilizer per unit area than the global average</a> and accounts for half the world’s total pesticide consumption. Overall, chemical use on Chinese farms is 2.5 times the global average per acre of land. </p>
<p>The overuse of synthetic fertilizer and pesticides has led to soil contamination, algae blooms and increased greenhouse gas emissions. Beyond the ecological consequences of the rapid rise in crop yields, Chinese consumers as well as farmers and farm workers have faced health problems. Over-application of fertilizers has led to chemical residues in food and <a href="https://dx.doi.org/10.1371%2Fjournal.pone.0033982">nitrogen infiltration into groundwater</a>.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/organic-agriculture-is-going-mainstream-but-not-the-way-you-think-it-is-92156">Organic agriculture is going mainstream, but not the way you think it is</a>
</strong>
</em>
</p>
<hr>
<p>But sustainable agriculture practices and organic food production are <a href="https://doi.org/10.4324/9780203701706">on the upswing in China</a>. The total area of certified organic agriculture cultivation increased more than five-fold between 2005 and 2018, to 3.1 million hectares, according to a 2019 government report. China ranked <a href="https://shop.fibl.org/chen/mwdownloads/download/link/id/1202">third in certified organic area in 2017</a>, after Australia and Argentina. Total organic sales in China ranked fourth globally, after the United States, Germany and France. Uncertified organic production is also widespread. </p>
<p>This shift is seeding a transformation towards a more sustainable food system within China — and around the world, given the <a href="https://ihsmarkit.com/research-analysis/agrifood-exports-of-china.html">US$65 billion of agri-food commodities exported from China</a> each year. This transformation provides lessons for the rest of world, in terms of efforts at both ends of the food supply chain to shift away from chemical-intensive agriculture towards a healthier system for people and the planet. </p>
<h2>Growing interest in sustainable agriculture</h2>
<p>Chinese farmers are ditching chemical agriculture for reasons of personal health, ecological protection and economic motives, propped up by a range of state supports. Chinese consumers are keen to sink their teeth into chemical-free food, primarily for health reasons. </p>
<p><a href="https://www.chinadialogue.net/article/show/single/en/10354-China-s-middle-class-gets-a-taste-for-healthy-eating">Demand for organic and so-called green foods is growing rapidly</a>, especially among the middle and upper classes. Japan, Europe and the U.S. are the biggest markets for Chinese organic food exports according to the Chinese Report on Organic Agriculture Certification and Industry Development in 2019.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/326672/original/file-20200408-83495-1jw8z3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/326672/original/file-20200408-83495-1jw8z3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/326672/original/file-20200408-83495-1jw8z3b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/326672/original/file-20200408-83495-1jw8z3b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/326672/original/file-20200408-83495-1jw8z3b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/326672/original/file-20200408-83495-1jw8z3b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/326672/original/file-20200408-83495-1jw8z3b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Steffanie Scott speaks with a vendor at the Beijing Organic Farmers’ Market.</span>
<span class="attribution"><span class="source">(Zhenzhong Si)</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Sustainable agriculture practices in China — such as using compost and animal manure instead of chemical fertilizer, cover crops, crop rotations and intercropping (growing different varieties of crops on one field) are contributing to <a href="https://www.ifoam.bio/en/core-campaigns/organic-agriculture-soils">healthier soils</a>. Ecological farms also <a href="https://www.coventry.ac.uk/globalassets/media/documents/research-documents/coventry-china-agriculture-aw-new-style.pdf">avoid the use of antibiotics and hormones in livestock</a>. </p>
<h2>Top-down and bottom-up efforts</h2>
<p>Organic social movements and organic markets have often emerged in countries with private land ownership, declining numbers of small farms and growing consolidation of food supply chains. China’s organic and ecological food sector is emerging amidst a different set of social, economic, cultural and environmental conditions. </p>
<p>This distinctive context in China has led to the development of a formal organic sector, created by top-down government standards and regulations. Alongside this, an informal organic sector has taken shape through bottom-up grassroots struggles for safe, healthy and sustainable food. </p>
<p>Through these top-down and bottom-up efforts, China is emerging as a global leader in developing sustainable food systems. A protracted <a href="https://www.theguardian.com/sustainable-business/2015/may/14/china-middle-class-organics-food-safety-scares">food safety crisis</a> was a driving force for shifting to more sustainable food production and for creating a domestic market for organic and ecologically grown food. </p>
<p>In response to food safety concerns, plus China’s ecological crisis, various levels of government in China now provide a wide range of <a href="https://doi.org/10.4324/9780203701706">supports to organic farms</a>. These measures are unparalleled around the world. They range from covering the cost of organic certification, to finding land, funding on-farm infrastructure and organic fertilizers, to training and marketing assistance. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/lessons-from-china-ensuring-no-one-goes-hungry-during-coronavirus-lockdowns-135781">Lessons from China: Ensuring no one goes hungry during coronavirus lockdowns</a>
</strong>
</em>
</p>
<hr>
<p>Alongside these state supports, bottom-up, civil society-driven efforts have also helped. A group of passionate food activists has introduced <a href="https://urgenci.net/csa-in-china-an-introduction-by-caroline-merrifield-and-shi-yan/">“community supported agriculture” farms</a>, <a href="https://doi.org/10.1007/s10460-014-9530-6">farmers’ markets and buying clubs</a>. This has contributed to a <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/apv.12127">revolution in ecological food and ethical eating in China’s cities</a>. </p>
<p>As our research shows, people have enthusiastically embraced these new community-based initiatives. They cherish the opportunity to access safe and healthy food, <a href="https://mp.weixin.qq.com/s/V78mrtvhzXjAdlFlJk9BhQ">even more so during the COVID-19 pandemic</a>. <a href="https://hungrycities.net/publication/hcp-discussion-paper-no-40-food-retailing-transitions-new-retail-businesses-nanjing-china/">Online sales, including of ecological and organic foods, are booming</a>, particularly among the middle and upper classes. </p>
<h2>Challenges ahead</h2>
<p>Despite these positive developments, China’s organic agriculture sector faces some critical challenges. For example, small-scale farmers cannot generally afford the paperwork for organic certification. </p>
<p>Fake organic certification labels have <a href="https://finance.china.com/consume/11173302/20180321/32209930_2.html">tested public trust of organic products</a> and the prices for organic foods can be five to 10 times greater than other food. And state officials are wary of promoting the model more widely as <a href="https://www.aginnovators.org.au/news/organic-farming-china">they remain skeptical that the yields are large enough</a> to feed China’s huge population.</p>
<p>Some of these issues could be addressed by investing in more research, and having organic sector support organizations provide training and information sharing. China also has few environmental NGOs to provide public education and connect farmers with one another for mutual support. </p>
<p>The world often views China’s environmental record in a <a href="https://www.cambridge.org/core/books/maos-war-against-nature/B2B796F91692D9D6E99675511C3D5FF4">negative light</a>. But much can be learned from both policy and grassroots efforts in this country. Farms like Ms. Wang’s fruit farm are taking root to reconnect farmers and eaters. And the national sustainable agriculture plan and policies to <a href="https://www.producer.com/daily/china-targets-zero-growth-in-chemical-fertilizer-use-in-2020/">curb agrochemical use</a> shed light on the prospects for sustainable agriculture in China.</p><img src="https://counter.theconversation.com/content/132407/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steffanie Scott has received funding from the Social Sciences and Humanities Council of Canada. </span></em></p><p class="fine-print"><em><span>Zhenzhong Si receives funding from the Social Sciences and Humanities Council of Canada and International Development Research Centre. </span></em></p>This transformation provides lessons for the rest of world, for shifting away from chemical agriculture towards a healthier system for people and the planet.Steffanie Scott, Professor of Geography & Environmental Management, University of WaterlooZhenzhong Si, Research Associate, Geography & Environmental Management, University of WaterlooLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1189022019-07-11T14:08:55Z2019-07-11T14:08:55ZHow your diet contributes to nutrient pollution and dead zones in lakes and bays<figure><img src="https://images.theconversation.com/files/281826/original/file-20190628-94696-13spbr0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Charter boat Capt. Dave Spangler holds a sample of algae from Maumee Bay in Lake Erie, Sept. 15, 2017.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Lake-Erie-Algae/70ba55b23a5a4f189c20b383141cf323/2/0">AP Photo/Paul Sancya, File</a></span></figcaption></figure><p>Every year in early summer, scientists at universities, research institutions and federal agencies release forecasts for the formation of “dead zones” and harmful algal blooms in the Gulf of Mexico, the Chesapeake Bay and Lake Erie. This year <a href="http://scavia.seas.umich.edu/hypoxia-forecasts/">the outlook is not good</a>. </p>
<p>The dead zone that forms annually in the Gulf of Mexico is likely to approach, if not surpass, record size at roughly 7,250 square miles. Another dead zone in the Chesapeake Bay is projected to be within the top 20% recorded over the past 20 years – about 2.1 cubic miles, equivalent to over 3.5 million Olympic-size swimming pools. And Lake Erie is also projected to set records, with almost 50,000 tons of potentially toxic algae. </p>
<p>The key factor driving these forecasts is winter and spring rainfall considerably above normal across the central U.S. The winter of 2018-2019 was the <a href="https://www.noaa.gov/news/us-records-wettest-winter-capped-by-cooler-wetter-february-2019">wettest on record</a> across the nation, and May was the <a href="https://www.ncei.noaa.gov/news/national-climate-201905">second-wettest month on record</a>. </p>
<p>Predicting the results isn’t rocket science. More rain means more flooding and more runoff from farmlands. These waters carry heavy loads of nutrients, mainly from fertilizer, that fuel algal blooms. The end results include <a href="https://www.thegazette.com/subject/news/government-treading-water-dead-zone-hypoxia-agricultural-runoff-fish-kill-nonpoint-source-pollution-surface-runoff-iowa-farmers-dnr-cover-crops-improve-water-quality-12022018">fish kills, closed beaches, possible drinking water alerts and loss of coastal property value</a>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/5LwbeK-QXNs?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Water in the Gulf of Mexico dead zone can contain less than half of the oxygen levels needed to support fish.</span></figcaption>
</figure>
<h2>Treading water</h2>
<p>Algal blooms occur when water bodies become overloaded with nitrogen and phosphorus from farms, water treatment plants and other sources. Warm water and nutrients promote rapid growth of algae. Some strains can be toxic or even fatal to aquatic life and humans.</p>
<p>Eventually algae settle to the bottom and decay. This process depletes dissolved oxygen in the water, creating “dead zones” where oxygen levels are low enough to kill fish.</p>
<p>Scientists and public officials have understood this problem for decades, but progress toward addressing it has been painfully slow. Nutrient loads, dead zones and harmful algal blooms in these systems dominated by agriculture have <a href="https://theconversation.com/forecasting-dead-zones-and-toxic-algae-in-us-waterways-a-bad-year-for-lake-erie-43747">increased or held grudgingly steady for decades</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/281852/original/file-20190628-94712-x1bv35.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/281852/original/file-20190628-94712-x1bv35.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/281852/original/file-20190628-94712-x1bv35.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=515&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281852/original/file-20190628-94712-x1bv35.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=515&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281852/original/file-20190628-94712-x1bv35.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=515&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281852/original/file-20190628-94712-x1bv35.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=648&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281852/original/file-20190628-94712-x1bv35.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=648&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281852/original/file-20190628-94712-x1bv35.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=648&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Dead zone and harmful algal bloom trends with 2019 forecasts in red.</span>
<span class="attribution"><span class="source">from http://scavia.seas.umich.edu/hypoxia-forecasts/</span></span>
</figcaption>
</figure>
<p>The main policy tool available now to combat nutrient losses from agricultural lands is the <a href="https://www.farmers.gov/farmbill">Farm Bill</a>, enacted about every five years, which provides <a href="https://theconversation.com/trump-budget-would-undo-gains-from-conservation-programs-on-farms-and-ranches-82420">funds for voluntary conservation efforts</a>. Between 1995 and 2015, the U.S. Department of Agriculture provided almost <a href="https://conservation.ewg.org/?_ga=2.138171184.145269961.1561742445-1342849811.1561742445">US$32 billion</a> in conservation incentive payments. U.S. water quality would be much worse without these programs, but they simply have not been sufficient to reduce nutrient loads over time. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/282125/original/file-20190702-105206-okzyf9.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/282125/original/file-20190702-105206-okzyf9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/282125/original/file-20190702-105206-okzyf9.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=531&fit=crop&dpr=1 600w, https://images.theconversation.com/files/282125/original/file-20190702-105206-okzyf9.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=531&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/282125/original/file-20190702-105206-okzyf9.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=531&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/282125/original/file-20190702-105206-okzyf9.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=667&fit=crop&dpr=1 754w, https://images.theconversation.com/files/282125/original/file-20190702-105206-okzyf9.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=667&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/282125/original/file-20190702-105206-okzyf9.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=667&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Nutrient load trends; 2019 loads in red.</span>
<span class="attribution"><span class="source">From: http://scavia.seas.umich.edu/hypoxia-forecasts/</span></span>
</figcaption>
</figure>
<h2>Warmer and wetter</h2>
<p>Scientists predict that as the climate warms, this problem is <a href="http://dx.doi.org/10.1126/science.aan2409">likely to get worse</a>. </p>
<p>Most climate models forecast <a href="https://nca2018.globalchange.gov/">increased precipitation</a>, especially intense spring rains, for most of the Midwest, the Great Lakes basin and the mid-Atlantic. As air warms, it can hold increasing amounts of water vapor, which <a href="https://theconversation.com/climate-change-is-driving-rapid-shifts-between-high-and-low-water-levels-on-the-great-lakes-118095">contributes to more precipitation</a> during extreme weather events. In turn, heavier rainfall will impact nutrient runoff and dead zone formation.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/281809/original/file-20190628-94716-aeezy9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/281809/original/file-20190628-94716-aeezy9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/281809/original/file-20190628-94716-aeezy9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=465&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281809/original/file-20190628-94716-aeezy9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=465&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281809/original/file-20190628-94716-aeezy9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=465&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281809/original/file-20190628-94716-aeezy9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=585&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281809/original/file-20190628-94716-aeezy9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=585&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281809/original/file-20190628-94716-aeezy9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=585&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Under a worst-case climate change scenario, in which global temperatures rise nearly 5 degrees Celsius above preindustrial levels by 2100, very heavy precipitation events in the Midwest, Great Plains and Southeast regions would increase sharply.</span>
<span class="attribution"><a class="source" href="https://www.climate.gov/sites/default/files/NCA4_heavy-precipitation-projected_large.jpg">NOAA</a></span>
</figcaption>
</figure>
<h2>A dietary strategy</h2>
<p>Farm-based conservation programs are important, and some new practices could <a href="https://doi.org/10.1016/j.ecoleng.2017.03.015">improve nutrient management</a>. For example, farmers can widen drainage ditches to create two-stage ditches, which allow water to flow onto vegetated side “benches” that capture nutrients during periods of heavy rainfall. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/282106/original/file-20190701-105187-p5m6x5.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/282106/original/file-20190701-105187-p5m6x5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/282106/original/file-20190701-105187-p5m6x5.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=154&fit=crop&dpr=1 600w, https://images.theconversation.com/files/282106/original/file-20190701-105187-p5m6x5.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=154&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/282106/original/file-20190701-105187-p5m6x5.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=154&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/282106/original/file-20190701-105187-p5m6x5.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=194&fit=crop&dpr=1 754w, https://images.theconversation.com/files/282106/original/file-20190701-105187-p5m6x5.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=194&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/282106/original/file-20190701-105187-p5m6x5.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=194&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A two-stage ditch has a low-flow channel and a vegetated side ‘benches’ that are flooded during higher flows. The grass slows water flow and allows nutrients to settle out.</span>
<span class="attribution"><a class="source" href="https://agbmps.osu.edu/bmp/open-channeltwo-stage-ditch-nrcs-582">Ohio State University Extension</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>But even these measures would have to be implemented at <a href="http://dx.doi.org/10.1002/fee.1472">unprecedented scales</a> to be effective. The challenge is even more daunting when recognizing that, for example, while the annual total phosphorus load to Lake Erie is large, it is only 10% of the amount applied in fertilizer each year. In addition, as with the Chesapeake and Mississippi watersheds, soils around Lake Erie are already laden with nitrogen and phosphorus. </p>
<p>In my view, part of the solution could be using markets to <a href="https://theconversation.com/industrial-corn-farming-is-ruining-our-health-and-polluting-our-watersheds-39721">drive a shift away from industrial-scale corn production</a>, which is a major source of nutrient pollution. One major step would be eliminating the federal mandate requiring oil companies to <a href="https://www.epa.gov/renewable-fuel-standard-program/overview-renewable-fuel-standard">blend corn-based ethanol into gasoline</a>, which consumes <a href="https://www.scientificamerican.com/article/time-to-rethink-corn/">40% of U.S. corn production</a>. </p>
<p>This will be politically difficult as long as presidential primaries <a href="https://www.politico.com/magazine/story/2019/03/05/2020-democrats-ethanol-225517">start in Iowa</a>. But other strategies may be more feasible, such as encouraging private-sector companies to demand <a href="https://fieldtomarket.org/">corn raised through more sustainable practices</a>.</p>
<p><a href="https://www.wri.org/publication/creating-sustainable-food-future#main-content">Reducing meat consumption</a>, which consumes another <a href="https://www.scientificamerican.com/article/time-to-rethink-corn/">36% of U.S. corn production</a> for animal feed, could also have a significant impact. Studies have shown that reducing this demand for row crops <a href="https://doi.org/10.1016/j.ecolmodel.2015.12.001">reduces nutrient pollution</a>. </p>
<p>This idea has gained momentum with the growth of the alternative meat industry. The success of startups like <a href="https://www.beyondmeat.com/">Beyond Meat</a> and <a href="https://impossiblefoods.com/">Impossible Foods</a> is luring giants like <a href="http://fortune.com/2019/06/13/tyson-plant-based-meat-pea-protein/">Tyson</a> and <a href="https://www.channelnewsasia.com/news/business/chicken-producer-perdue-enters-crowded-plant-based-meat-market-11629576">Perdue</a> into the game. Some are even struggling to keep up with demand for plant-based meat alternatives, <a href="https://www.nytimes.com/2019/06/15/business/impossible-foods-burger-demand.html">particularly in China</a>. One recent market analysis suggests that plant-based “meat” will <a href="https://www.atkearney.com/retail/article/?/a/how-will-cultured-meat-and-meat-alternatives-disrupt-the-agricultural-and-food-industry">surpass animal sources globally by 2040</a>. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/281824/original/file-20190628-94716-1gts8g7.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/281824/original/file-20190628-94716-1gts8g7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/281824/original/file-20190628-94716-1gts8g7.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=375&fit=crop&dpr=1 600w, https://images.theconversation.com/files/281824/original/file-20190628-94716-1gts8g7.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=375&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/281824/original/file-20190628-94716-1gts8g7.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=375&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/281824/original/file-20190628-94716-1gts8g7.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=472&fit=crop&dpr=1 754w, https://images.theconversation.com/files/281824/original/file-20190628-94716-1gts8g7.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=472&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/281824/original/file-20190628-94716-1gts8g7.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=472&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.atkearney.com/retail/article/?/a/how-will-cultured-meat-and-meat-alternatives-disrupt-the-agricultural-and-food-industry">AT Kearney</a>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Shrinking agriculture’s footprint</h2>
<p>Scientists have understood for decades that excess nitrogen and phosphorus degrade Lake Erie, the Chesapeake Bay and the Gulf of Mexico. Nutrient inputs from sewage treatment plants and other discreet, easily identifiable sources have declined because they are regulated under the Clean Water Act. </p>
<p>But the nutrients fouling these water bodies now come mostly from diffuse sources, particularly industrial-scale row crop agriculture. Those operations are not subject to the Clean Water Act, and voluntary conservation programs seem to have at best kept pace with the expansion of large-scale farming. </p>
<p>After analyzing these issues and providing policy advice on them for much of my 45-year career, it’s frustrating to see so little change. But I am hopeful that current work that addresses agricultural pollution in broader contexts may have an impact. </p>
<p>For example, recent reports connecting <a href="https://doi.org/10.1016/S0140-6736(18)31788-4">reduced meat consumption</a> to both positive environmental effects and improved health should provide additional incentives for change. <a href="https://www.wri.org/publication/creating-sustainable-food-future#main-content">Research institutes</a> and <a href="https://doi.org/10.1146/annurev-environ-102017-025957">scholars</a> are laying out comprehensive global pathways to more sustainable agriculture that are designed to feed the world and protect and restore natural ecosystems. </p>
<p>My hope lies in the combination of health- and market-driven movement toward plant-based meat substitutes and enlightened policies that support more sustainable practices in agriculture’s critical role of providing food and fiber to the world.</p><img src="https://counter.theconversation.com/content/118902/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Donald Scavia has received funding from the National Science Foundation, the Environmental Protection Agency, the National Oceanic and Atmospheric Administration, Environment and Climate Change Canada, the Erb Family Foundation, the Joyce Foundation, and the C.S. Mott Foundation.</span></em></p>Scientists are predicting major algae blooms in Lake Erie and large dead zones in the Chesapeake Bay and Gulf of Mexico this summer. Nutrient pollution from industrial corn farming is a major driver.Donald Scavia, Professor Emeritus, School for Environment and Sustainability, University of MichiganLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1130522019-03-29T13:20:00Z2019-03-29T13:20:00ZFeeding farm animals seaweed could help fight antibiotic resistance and climate change<figure><img src="https://images.theconversation.com/files/266530/original/file-20190329-70982-1czv13a.jpg?ixlib=rb-1.1.0&rect=11%2C0%2C7337%2C4912&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/forest-seaweed-1034470153">Divedog/Shutterstock</a></span></figcaption></figure><p>Demand for food is increasing rapidly – the <a href="https://www.un.org/development/desa/en/news/population/world-population-prospects-2017.html">global population is expected to reach 11.2 billion</a> by 2100. To keep up with the additional mouths to feed, intensive farming practices have maximised production, but often at the expense of the environment and human health.</p>
<p>Livestock is reared to maximise economic returns, which often means animals are kept in <a href="https://www.theguardian.com/environment/2017/jul/17/uk-has-nearly-800-livestock-mega-farms-investigation-reveals">close confinement</a> with each other, increasing the risk of disease. As a result, antibiotics are often used to treat animals destined for human consumption, but relying on them can <a href="https://www.cdc.gov/antibiotic-use/community/about/antibiotic-resistance-faqs.html">cause bacteria to develop resistance</a> in the long run. A recent review found 100 academic studies <a href="https://amr-review.org/sites/default/files/Antimicrobials%20in%20agriculture%20and%20the%20environment%20-%20Reducing%20unnecessary%20use%20and%20waste.pdf">on antimicrobial resistance</a> had detected a link between antibiotic consumption in animals and antimicrobial resistance in humans. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/266533/original/file-20190329-71006-u7w8je.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266533/original/file-20190329-71006-u7w8je.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266533/original/file-20190329-71006-u7w8je.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266533/original/file-20190329-71006-u7w8je.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266533/original/file-20190329-71006-u7w8je.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266533/original/file-20190329-71006-u7w8je.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266533/original/file-20190329-71006-u7w8je.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Rearing livestock in crowded farms can help diseases spread.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/cows-farm-dairy-560358073">Ewa Studio/Shutterstock</a></span>
</figcaption>
</figure>
<p>This means that using antibiotics in animal rearing can cause resistant bacteria that may also affect humans down the food chain. <a href="http://www.fairr.org/news-item/eu-ban-antibiotics-hailed-victory-responsible-investors/">Antibiotics have been phased out of livestock rearing</a> in the EU and in their place zinc has been introduced into the diet of animals to help kill bacteria which cause Salmonella and E. coli.</p>
<p>High levels of zinc in the diets of pigs and cows can <a href="https://phys.org/news/2016-04-higher-zinc-cattle-efficiency.html">help them grow bigger</a> and kill E. coli, but it’s starting to become an environmental issue in its own right. Most of the zinc fed to the animals is <a href="https://www.sciencedirect.com/science/article/pii/S240565451730015X">excreted and washed into waterways and soils</a> where it can harm aquatic life and <a href="https://www.lenntech.com/periodic/elements/zn.htm">acidify the soil</a>. As a result, European legislation will <a href="https://www.fwi.co.uk/livestock/pigs/zinc-oxide-to-be-phased-out-in-pig-production-by-2022">phase out the use of zinc</a> by 2022.</p>
<p>This leaves the producers of livestock feed and farmers in a difficult position. New products are needed to prevent infection in livestock which don’t harm the environment or human health by contributing to antimicrobial resistance, but where could they come from?</p>
<h2>Let them eat seaweed</h2>
<p>Seaweed could be the answer. Brown seaweeds synthesise a <a href="https://www.sciencedirect.com/science/article/pii/S1878535213003377">unique class of compound called phlorotannins</a> as they grow. These compounds can kill bacteria that emerge among farm animals. How effectively these compounds can kill bacteria depends on the species of seaweed being used, with different species producing more potent bactericides.</p>
<p>The flock of North Ronaldsay sheep in Scotland have <a href="https://www.atlasobscura.com/articles/seaweed-sheep-north-ronaldsay-orkney-festival">grazed on nothing but seaweed</a> for generations. Animals raised on such diets which are rich in Omega-3 fatty acids <a href="https://www.seaweedandco.com/seaweed-in-beef/">produce healthier – and arguably tastier – meat</a>.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/266531/original/file-20190329-71003-6bwizl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266531/original/file-20190329-71003-6bwizl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266531/original/file-20190329-71003-6bwizl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266531/original/file-20190329-71003-6bwizl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266531/original/file-20190329-71003-6bwizl.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266531/original/file-20190329-71003-6bwizl.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266531/original/file-20190329-71003-6bwizl.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A sheep grazes on brown seaweed.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/seaweed-eating-sheep-654561931">Forge Photography/Shutterstock</a></span>
</figcaption>
</figure>
<p>Seaweed can be grown in the ocean and harvested from natural stocks in a rotational manner, <a href="https://theconversation.com/putting-algae-and-seaweed-on-the-menu-could-help-save-our-seafood-88980">ensuring natural habitats don’t have to be plundered</a> to supply livestock farmers. Seaweed farming also doesn’t have to compete for land space like traditional feed crops and could reduce pressure on agricultural land – allowing space for habitat restoration and rewilding <a href="https://theconversation.com/rewilding-is-essential-to-the-uks-commitments-on-climate-change-107541">which helps fight climate change</a>.</p>
<p>Seaweed farms in the ocean <a href="https://theconversation.com/how-farming-giant-seaweed-can-feed-fish-and-fix-the-climate-81761">draw in a lot of carbon dioxide</a> – which <a href="https://www.hakaimagazine.com/news/seaweed-and-seagrass-buffer-the-acidity-of-the-nearby-ocean/">helps de-acidify the seawater</a> around them – and release oxygen. This improves the health of sea life nearby and helps organisms such as coral or sea snails to grow stronger exoskeletons of calcium carbonate.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/266529/original/file-20190329-71016-1385hne.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/266529/original/file-20190329-71016-1385hne.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/266529/original/file-20190329-71016-1385hne.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/266529/original/file-20190329-71016-1385hne.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/266529/original/file-20190329-71016-1385hne.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/266529/original/file-20190329-71016-1385hne.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/266529/original/file-20190329-71016-1385hne.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Rows of seaweed growing on a farm in Jambiani, Zanzibar island, Tanzania.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/rows-seaweed-on-farm-jambiani-zanzibar-794705638">Ventura/Shutterstock</a></span>
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</figure>
<p>Modern farming uses <a href="https://oceanservice.noaa.gov/facts/eutrophication.html">huge quantities of fertiliser</a> which run off the land and into rivers and the ocean. There, these nutrients stimulate algae which grow and multiply. When algal blooms die and decay, they’re decomposed by bacteria which absorb oxygen from the water, <a href="https://theconversation.com/coastal-dead-zones-on-the-rise-15496">creating vast dead zones</a> where fish and other aquatic life suffocate. Luckily, growing seaweed requires no fertiliser and only uses nutrients which already exist in seawater.</p>
<p>Global seaweed production rose from 10.5 to 28.4 million tonnes between 2000 and 2014, but <a href="https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/546679/FC002I__Cefas_Seaweed_industry_report_2016_Capuzzo_and_McKie.pdf">95% of this was in Asia</a>. There’s therefore huge growth potential for seaweed agriculture in the rest of the world. The brown seaweeds which produce the helpful antibacterial compounds are <a href="https://www.discoverwildlife.com/how-to/identify-wildlife/how-to-identify-seaweed/">widespread on temperate shores</a>, and by converting them into supplements for livestock feed, a vibrant industry that’s good for humans and the environment could flourish.</p>
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<img alt="" src="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=140&fit=crop&dpr=1 600w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=140&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=140&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=176&fit=crop&dpr=1 754w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=176&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/263883/original/file-20190314-28475-1mzxjur.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=176&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<p><em><a href="https://theconversation.com/imagine-newsletter-researchers-think-of-a-world-with-climate-action-113443?utm_source=TCUK&utm_medium=linkback&utm_campaign=TCUKengagement&utm_content=Imagineheader1113052">Click here to subscribe to our climate action newsletter. Climate change is inevitable. Our response to it isn’t.</a></em></p><img src="https://counter.theconversation.com/content/113052/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lauren Ford receives funding from Agri Food Quest Competence Centre funded by Invest Northern Ireland to research Algal Animal Feeds INI Agri-Food QUEST - 11-01-17-003 - AFQCC.</span></em></p><p class="fine-print"><em><span>Pamela Judith Walsh receives funding from Agri Food Quest Competence Centre funded by Invest Northern Ireland to research Algal Animal Feeds (INI Agri-Food QUEST - 11-01-17-003 - AFQCC). </span></em></p>Feeding pigs seaweed could make them, us and the planet healthier without contributing to antibiotic resistance in bacteria.Lauren Ford, Research Fellow, Queen's University BelfastPamela Judith Walsh, Lecturer in Chemical Engineering, Queen's University BelfastLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/996552018-11-13T11:45:15Z2018-11-13T11:45:15ZVolcanic eruptions once caused mass extinctions in the oceans – could climate change do the same?<figure><img src="https://images.theconversation.com/files/244880/original/file-20181110-116820-13h326t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Surgeonfish on a reef in the Maldives. </span> <span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Shoaling_and_schooling#/media/File:Maldives_Surgeonfish,_Acanthurus_leucosternon.jpg">Uxbona/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>All animals, whether they live on land or in the water, require oxygen to breathe. But today the world’s oceans are <a href="https://theconversation.com/the-ocean-is-losing-its-breath-and-climate-change-is-making-it-worse-66192">losing oxygen,</a> due to a combination of rising temperatures and changing ocean currents. Both factors are driven by human-induced climate change.</p>
<p>This process has the potential to <a href="https://theconversation.com/climate-change-could-alter-ocean-food-chains-leading-to-far-fewer-fish-in-the-sea-93114">disrupt marine food chains</a>. We already know that large hypoxic, or low-oxygen, zones can be deadly. If hypoxia expands in both size and duration, it is possible to cause widespread extinction of marine life, which has happened previously in Earth’s history.</p>
<p>We investigate natural, ancient changes in ocean oxygenation and the biological effects as a way of understanding the natural response to potential future climate scenarios. In a <a href="https://doi.org/10.1073/pnas.1803478115">recent study</a>, we examined links between a major volcanic event that occurred millions of years ago and changes in ocean oxygen levels. Like human activities today, this event released massive amounts of carbon dioxide and other greenhouse gases into the atmosphere. </p>
<p>We found that this episode appeared to trigger significant oxygen losses in the world’s ocean that lasted over one million years. Our research adds to growing evidence that marine oxygen contents are dramatically affected by warming temperatures and other climate-related feedbacks caused by the release of greenhouse gases.</p>
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<iframe width="440" height="260" src="https://www.youtube.com/embed/hrHGwFrqIgg?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Climate change is reducing the ocean’s ability to hold oxygen and increasing marine organisms’ need for it.</span></figcaption>
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<h2>Are our oceans suffocating?</h2>
<p>Scientists widely agree that human activities – mainly fossil fuel combustion, deforestation and agricultural practices – are releasing carbon dioxide and methane into the atmosphere at <a href="https://doi.org/10.1038/ngeo2681">unprecedented rates</a>. For the past several decades, research on climate change impacts has focused on global warming, sea level rise and ocean acidification. Now, loss of ocean oxygen is starting to receive attention.</p>
<p>The world’s oceans have lost <a href="https://doi.org/10.1038/nature21399">more than 2 percent of their dissolved oxygen reservoir</a> over the past five decades. In many places local factors such as nutrient pollution are making the problem worse. In U.S. waters, major hypoxic zones regularly form in the <a href="https://www.noaa.gov/media-release/gulf-of-mexico-dead-zone-is-largest-ever-measured">Gulf of Mexico</a>, the <a href="https://theconversation.com/nutrient-pollution-voluntary-steps-are-failing-to-shrink-algae-blooms-and-dead-zones-81249">Great Lakes</a> and along the <a href="https://www.npr.org/2018/10/28/658953894/coastal-pacific-oxygen-levels-now-plummet-once-a-year">Pacific coast</a>. Other coastal waters are <a href="https://www.wri.org/resource/world-hypoxic-and-eutrophic-coastal-areas">similarly impacted around the world</a>.</p>
<p>Hypoxia can devastate fish catches. For example, a <a href="https://doi.org/10.1016/j.marpolbul.2008.03.028">major fish kill in the Philippines</a> in 2002 was directly associated with declining oxygen levels in the water. A similar event occurred in Redondo Beach, California in 2011 when hypoxic conditions over several days <a href="https://doi.org/10.3354/meps09927">decimated the local fish population</a>. Ultimately, these events have <a href="http://dx.doi.org/10.1126/science.aam7240">significant impacts on humans</a>, since 40 percent of the world’s population lives within roughly 60 miles of the ocean. <a href="http://www.fao.org/zhc/detail-events/en/c/233771/">Millions of people depend on fish</a> for food, income or both.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/244877/original/file-20181110-116838-1ujxbtm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/244877/original/file-20181110-116838-1ujxbtm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/244877/original/file-20181110-116838-1ujxbtm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/244877/original/file-20181110-116838-1ujxbtm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/244877/original/file-20181110-116838-1ujxbtm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/244877/original/file-20181110-116838-1ujxbtm.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/244877/original/file-20181110-116838-1ujxbtm.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/244877/original/file-20181110-116838-1ujxbtm.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Dead sardines float on the surface at King Harbor Marina in Redondo Beach, California, March 10, 2011 during a deoxygenation event.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Fish-Die-off/2c2be589704243eeb413e8d89e4e710a/4/0">AP Photo/Noaki Schwartz</a></span>
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<h2>Linking ancient oxygen loss to a marine mass extinction</h2>
<p>Past volcanic eruptions are probably our only ancient analogs to modern release of greenhouse gases from human activities. To understand how these events affected the oceans, we turned to ancient marine rocks that can record the relationship between carbon dioxide releases from volcanoes, marine oxygen levels and extinction events. </p>
<p>One such event, which occurred 183 million years ago during the Early Jurassic, is called the Toarcian Oceanic <a href="https://en.wikipedia.org/wiki/Anoxic_event">Anoxic Event</a>. It is renowned for major volcanism and the seventh-largest mass extinction in Earth’s history, which occurred predominantly in the oceans. The volcanism that occurred was much larger in scale than all modern volcanoes, and would have released massive amounts of greenhouse gases to the atmosphere, warming the planet dramatically.</p>
<p>We applied a new and novel tool – thallium isotopes – to determine the timing and amount of oxygen loss from the oceans during this event. Thallium is a soft, silvery metal that is found in various ores, including <a href="https://www.livescience.com/39303-thallium.html">balls of manganese on the ocean floor</a>. Isotopes are atoms of the same element that have slight mass differences because they contain varying numbers of neutrons.</p>
<p>Numerous minerals form in the ocean, often through reactions that involve oxygen. But the amount of free oxygen in seawater is not constant in the modern ocean, and has also varied in time. When oxygen is abundant in the ocean, manganese oxides deposit on the ocean floor, and thallium – especially its heavier isotopes – stick to them. By analyzing ancient marine sediments and looking for shifts in thallium’s isotopic value, we hypothesized that we could track the progressive loss of ocean oxygen.</p>
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<a href="https://images.theconversation.com/files/244872/original/file-20181110-36763-137mls5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/244872/original/file-20181110-36763-137mls5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/244872/original/file-20181110-36763-137mls5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/244872/original/file-20181110-36763-137mls5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/244872/original/file-20181110-36763-137mls5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/244872/original/file-20181110-36763-137mls5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/244872/original/file-20181110-36763-137mls5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/244872/original/file-20181110-36763-137mls5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Ammonite fossil from Alberta, Canada. This ammonite evolved at the end of the Toarcian Oceanic Anoxic Event and associated marine mass extinction and was used to help determine the age of the rocks.</span>
<span class="attribution"><span class="source">Benjamin Gill</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>To do this, we collected specific dark-colored sedimentary rocks from this time period at sites in Canada and Germany, which represented two different ancient oceans. We then dissolved each layer of rock to form a liquid, and isolated and purified the thallium in each sample. </p>
<p>We found that thallium isotopes shifted in two stages during this event. First the oceans became less oxygenated during the onset of massive volcanism, approximately 183.8 million years ago to 183.1 million years ago. Then the oceans lost even more oxygen, coinciding with the most intense phase of volcanism, which occurred from 183.1 million years ago to 182.6 million years ago.</p>
<p>This work shows for the first time that the global ocean lost oxygen <a href="https://doi.org/10.1073/pnas.1803478115">coincidentally with the onset of volcanism</a>. Importantly, this happened at the onset of a known extinction called the <a href="https://doi.org/10.1016/j.palaeo.2013.05.010">Pliensbachian-Toarcian mass extinction event</a>. In other words, the first signs of the extinction in the fossil record coincide with oxygen loss in the oceans. </p>
<p>We now think that this state of low-oxygen marine conditions lasted for over one million years and across two extinction pulses. The second phase of deoxygenation was more expansive, thus causing a larger extinction. It happened even though the atmosphere contained enough oxygen to support life, much like today. Furthermore, the duration of low oxygen conditions was similar to <a href="http://dx.doi.org/10.1126/sciadv.1701020">another event</a> that occurred 94 million years ago with biological consequences.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/244879/original/file-20181110-116820-1ttyykq.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/244879/original/file-20181110-116820-1ttyykq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/244879/original/file-20181110-116820-1ttyykq.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=366&fit=crop&dpr=1 600w, https://images.theconversation.com/files/244879/original/file-20181110-116820-1ttyykq.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=366&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/244879/original/file-20181110-116820-1ttyykq.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=366&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/244879/original/file-20181110-116820-1ttyykq.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=460&fit=crop&dpr=1 754w, https://images.theconversation.com/files/244879/original/file-20181110-116820-1ttyykq.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=460&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/244879/original/file-20181110-116820-1ttyykq.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=460&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Ocean mass extinction events over the past 542 million years. Time (millions of years ago) runs from left to right on the horizontal axis. The vertical axis shows percent of species lost.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Extinction_intensity.svg">Smith609/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>A global warming threshold?</h2>
<p>The Intergovernmental Panel on Climate Change recently released a <a href="http://www.ipcc.ch/report/sr15/">Special Report on Global Warming of 1.5°C</a>, which called for immediate action to limit climate change to levels that will minimize environmental and ecosystem stress. Scientists broadly agree that this means preventing global average temperatures from rising more than 1.5 degrees Celsius above preindustrial levels.</p>
<p>The report notes that if temperatures increase by 2°C instead of 1.5°C, substantially more oxygen loss will occur in the oceans. This makes it important to continue studying ancient impacts of oxygen loss on the extinction record, so that scientists can better predict future climate scenarios. It is also important to identify areas that will be most impacted by ocean oxygen loss and limit the environmental effects that will occur as our planet continues to warm.</p><img src="https://counter.theconversation.com/content/99655/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Jeremy D. Owens receives funding from National Science Foundation and National Aeronautics and Space Administration. </span></em></p><p class="fine-print"><em><span>Theodore R. Them II does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Drastic oxygen losses in the world’s oceans millions of years ago coincided with mass extinctions. Scientists see this as a warning about how climate change could affect oceans today.Jeremy D. Owens, Assistant Professor of Earth, Ocean and Atmospheric Science, Florida State UniversityTheodore R. Them II, Assistant Professor, College of CharlestonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/927162018-03-05T20:15:10Z2018-03-05T20:15:10ZCutting pollution in the Chesapeake Bay has helped underwater grasses rebound<figure><img src="https://images.theconversation.com/files/208924/original/file-20180305-146700-osn6fj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Healthy aquatic vegetation in the Chesapeake Bay.</span> <span class="attribution"><span class="source">Cassie Gurbisz/University of Maryland Center for Environmental Science</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span></figcaption></figure><p>Seagrasses are the “coastal canaries” of oceans and bays. When these underwater flowering plants are sick or dying, it means the ecosystem is in big trouble – typically due to pollution that reduces water quality. But when they are thriving and expanding, it is a sign that the ecosystem is becoming healthier. </p>
<p>We have collaborated on seagrass research for three decades in the Chesapeake Bay and beyond. One of us (Bob “JJ” Orth) has mapped and <a href="https://scholar.google.com/citations?user=bVEVdsEAAAAJ&hl=en">studied</a> the bay’s submerged aquatic vegetation since the 1980s. And the other (Bill Dennison) <a href="https://scholar.google.com/citations?user=NfbBjykAAAAJ&hl=en">studies</a> seagrass ecophysiology and has led efforts to make this science understandable and useful. </p>
<p>Seagrasses are critical to a healthy Chesapeake Bay. They provide habitat for fish and shellfish, stabilize sediments and help clarify the water. The bay’s grasses declined sharply in the 1970s, as pollution and development degraded its water quality. States around the bay have been working together since 2010 on a sweeping plan to clean it up and restore its ecosystems.</p>
<p>In a new <a href="http://dx.doi.org/10.1073/pnas.1715798115">study</a>, we provide conclusive evidence that reducing discharges of nitrogen, phosphorus and other pollutants into the bay has produced the largest resurgence of underwater grasses ever recorded anywhere. This success shows that coastal ecosystems are resilient and that concerted efforts to reduce nutrient pollution can result in substantial improvements.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/208935/original/file-20180305-146661-ifomwk.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/208935/original/file-20180305-146661-ifomwk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/208935/original/file-20180305-146661-ifomwk.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=309&fit=crop&dpr=1 600w, https://images.theconversation.com/files/208935/original/file-20180305-146661-ifomwk.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=309&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/208935/original/file-20180305-146661-ifomwk.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=309&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/208935/original/file-20180305-146661-ifomwk.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=389&fit=crop&dpr=1 754w, https://images.theconversation.com/files/208935/original/file-20180305-146661-ifomwk.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=389&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/208935/original/file-20180305-146661-ifomwk.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=389&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Trends in acreage and density of submerged aquatic vegetation in the Chesapeake Bay.</span>
<span class="attribution"><span class="source">Melissa Merritt/USEPA</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<h2>Cutting nutrient pollution boosts seagrasses</h2>
<p>Ten years ago we led an effort through the <a href="https://www.nceas.ucsb.edu/">National Center for Ecological Analysis and Synthesis</a> to understand the global trajectories of seagrasses. What we found was that seagrasses were being <a href="https://doi.org/10.1073/pnas.0905620106">lost at an alarming rate</a>, equivalent to a soccer field of seagrass every 30 minutes since 1980. </p>
<p>So when we began to observe net increases over the past few years in the abundance of multiple types of seagrasses (collectively known as submerged aquatic vegetation) in our beloved Chesapeake Bay, we knew this event was globally unique.</p>
<p>To discern what was happening, we partnered with the <a href="http://www.chesapeakebay.net/">Chesapeake Bay Program</a> to initiate what is called a synthesis effort. Synthesis science brings together diverse teams of experts from different fields to pull new insights out of existing data.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/208808/original/file-20180304-65529-eczkeu.png?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/208808/original/file-20180304-65529-eczkeu.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/208808/original/file-20180304-65529-eczkeu.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=690&fit=crop&dpr=1 600w, https://images.theconversation.com/files/208808/original/file-20180304-65529-eczkeu.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=690&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/208808/original/file-20180304-65529-eczkeu.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=690&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/208808/original/file-20180304-65529-eczkeu.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=867&fit=crop&dpr=1 754w, https://images.theconversation.com/files/208808/original/file-20180304-65529-eczkeu.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=867&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/208808/original/file-20180304-65529-eczkeu.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=867&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Pollution sources throughout the Bay’s watershed affect its water quality.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/1/1e/Chesapeake_Bay_Watershed.png">USGS</a></span>
</figcaption>
</figure>
<p>We had access to 30 years of annual surveys of underwater grasses that JJ Orth personally oversees, plus a 30-year water quality data set collected by the Chesapeake Bay Program. Scientists from the <a href="http://www.vims.edu">Virginia Institute of Marine Science</a>, <a href="https://www.umces.edu">University of Maryland Center for Environmental Science</a>, <a href="https://www.bigelow.org/">Bigelow Laboratory for Ocean Sciences</a>, the <a href="https://www.usgs.gov/">U.S. Geological Survey</a>, the <a href="https://www.sesync.org/">National Socio-Environmental Synthesis Center</a>, <a href="http://www.smcm.edu/">St. Mary’s College of Maryland</a>, the <a href="https://serc.si.edu/">Smithsonian Environmental Research Center</a>, the <a href="http://dnr.maryland.gov/Pages/default.aspx">Maryland Department of Natural Resources</a>, <a href="https://www.tamucc.edu/">Texas A&M University-Corpus Christi</a> and the <a href="https://www.epa.gov/">U.S. Environmental Protection Agency</a> provided analytical firepower to help assess this complex information.</p>
<p>We started by identifying ways in which activities on land could affect trends in water quality and underwater grass abundance. Then we tested our hypothesized linkages using structural equation models that analyzed data in two different ways. </p>
<p>One approach focused on the cascade of nitrogen and phosphorus moving from sources on land, such as wastewater discharge and stormwater runoff, into waterways. The other showed what happened to underwater grasses once these nutrients entered in the water. Nutrients overfertilize the bay, creating huge blooms of algae that die and deplete oxygen from the water. This produces “<a href="https://doi.org/10.1093/biosci/bix048">dead zones</a>” that cannot support fish or plant life.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/208936/original/file-20180305-146675-1oy2crf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/208936/original/file-20180305-146675-1oy2crf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/208936/original/file-20180305-146675-1oy2crf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=181&fit=crop&dpr=1 600w, https://images.theconversation.com/files/208936/original/file-20180305-146675-1oy2crf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=181&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/208936/original/file-20180305-146675-1oy2crf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=181&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/208936/original/file-20180305-146675-1oy2crf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=228&fit=crop&dpr=1 754w, https://images.theconversation.com/files/208936/original/file-20180305-146675-1oy2crf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=228&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/208936/original/file-20180305-146675-1oy2crf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=228&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Historic photos show water quality declining and underwater grasses disappearing off Solomons, Maryland.</span>
<span class="attribution"><span class="source">Chesapeake Biological Laboratory/University of Maryland Center for Environmental Science</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>In our analysis, we found conclusive evidence that reductions of excess nitrogen and phosphorus caused the underwater grass recovery in the Chesapeake Bay. Since 1984, the quantity of nitrogen entering the bay has decreased by 23 percent and phosphorus has fallen by 8 percent, thanks to a “<a href="https://www.epa.gov/chesapeake-bay-tmdl">pollution diet</a>” that the EPA <a href="https://theconversation.com/supreme-court-sides-with-epa-on-cleaning-chesapeake-bay-and-perhaps-other-waterways-55678">established in 2010</a>. The plan, formally called a Total Maximum Daily Load (TMDL), requires states in the bay’s 64,000-square mile watershed to reduce specific pollutants entering the bay to target levels on a fixed schedule.</p>
<p>As a result, underwater grasses have increased by over 300 percent and have reappeared in some locations around the bay where they had not been observed for decades.</p>
<h2>A healthier Chesapeake Bay</h2>
<p>For the past 12 years, we have been using underwater grasses and other water quality data to produce an annual <a href="https://ecoreportcard.org/report-cards/chesapeake-bay/">Chesapeake Bay report card</a>. Our 2017 report card describes progress across the board, with 7 out of 15 reporting regions around the bay showing significant improvement and the rest holding steady. </p>
<p>We attribute these improvements to the TMDL plan. In particular, <a href="http://ian.umces.edu/pdfs/ian_report_438.pdf">upgrades at area wastewater treatment facilities</a> have reduced nitrogen and phosphorus inputs into the bay. <a href="http://dx.doi.org/10.1021/es4028748">Catalytic converters on automobiles and smokestack scrubbers in power plants</a> have reduced atmospheric nitrogen emissions and subsequent deposition that finds its way into bay waters. It appears that these management actions are beginning to pay off, although there is more to do – especially reducing nutrient pollution from agriculture.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/z3-XhBU08xM?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">Seagrasses in the Chesapeake Bay’s Susquehanna Flats are rebounding.</span></figcaption>
</figure>
<h2>Progress at risk</h2>
<p>The Chesapeake Bay Program is a partnership between six states (New York, Pennsylvania, Maryland, Delaware, West Virginia, Virginia), the District of Columbia and the federal government, represented by the EPA. It heavily leverages federal funding by engaging community groups, local municipalities and nongovernmental organizations to carry out actions that help reduce pollution entering the bay. Examples include re-engineering urban surfaces to reduce stormwater runoff and subsidizing farmers to grow winter cover crops that help retain nutrients on fields. </p>
<p>When EPA Administrator Scott Pruitt was Oklahoma’s attorney general, he joined other states in a lawsuit to block the Chesapeake Bay cleanup, calling it a federal overreach. Now, however, Pruitt has <a href="http://www.baltimoresun.com/news/maryland/politics/bs-md-scott-pruitt-20170118-story.html">pledged to support the program</a>, which was upheld by a federal court in <a href="https://www.epa.gov/chesapeake-bay-tmdl/chesapeake-bay-tmdl-court-decisions">2013</a> and sustained on appeal in 2015. </p>
<p>But President Trump’s 2017 budget called for eliminating the Chesapeake Bay Program completely. Congress enacted only small cuts, but Trump’s 2018 budget request cuts the program’s funding by 90 percent – ironically, just when we are finally starting to reverse degradation from past decades. </p>
<p>The Chesapeake Bay is arguably the best-studied estuary on the planet, and the fact that our study connects management actions to a huge resurgence of underwater grasses is a tribute to this rich history. Ongoing efforts to restore the bay have produced lessons about how pollution abatement can lead to ecosystem recovery. </p>
<p>These insights can and should be applied to <a href="https://theconversation.com/nutrient-pollution-voluntary-steps-are-failing-to-shrink-algae-blooms-and-dead-zones-81249">other water bodies affected by nutrient pollution</a>. We hope the story of the Chesapeake Bay’s recovery inspires similar actions in many other places.</p><img src="https://counter.theconversation.com/content/92716/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bill Dennison receives funding from the Chesapeake Bay Program. </span></em></p><p class="fine-print"><em><span>Robert J. Orth receives funding from the U.S. Environmental Protection Agency, the Virginia Department of Environmental Quality, the Virginia Coastal Zone Management Program and the Maryland Department of Natural Resources. He serves as a district representative on the Gloucester County, Virginia Board of Supervisors, to which he was elected as an Independent.</span></em></p>An ambitious plan to cut the flow of nutrients into the Chesapeake Bay has produced historic regrowth of underwater seagrasses. These results offer hope for other polluted water bodies.Bill Dennison, Professor of Marine Science and Vice President for Science Applications, University of Maryland Center for Environmental ScienceRobert J. Orth, Professor of Marine Science, Virginia Institute of Marine ScienceLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/821752017-08-11T13:32:00Z2017-08-11T13:32:00ZGulf of Mexico ‘dead zone’ is already a disaster – but it could get worse<figure><img src="https://images.theconversation.com/files/181535/original/file-20170809-3360-mssrh8.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Harvepino / shutterstock</span></span></figcaption></figure><p>Each summer, a large part of the Gulf of Mexico “dies”. This year, the Gulf’s “dead zone” is the <a href="http://www.noaa.gov/media-release/gulf-of-mexico-dead-zone-is-largest-ever-measured">largest on record</a>, stretching from the mouth of the Mississippi, along the coast of Louisiana to waters off Texas, hundreds of miles away. Around 8,776 square miles of ocean, an area the size of New Jersey or Wales, is almost lifeless.</p>
<p>John Muir, the famed naturalist and early conservation campaigner, <a href="http://vault.sierraclub.org/john_muir_exhibit/writings/misquotes.aspx">once said</a> that: “When we try to pick out anything by itself, we find it hitched to everything else in the Universe.” His point was that everything in nature is connected, and that no part of our ecosystem exists entirely independently from any other.</p>
<p>It is perhaps no surprise then that ultimate cause of the Gulf of Mexico’s dead zone can be found many miles inland. Fertilisers used by farmers then wash into the Mississippi River and eventually into the sea, where nutrients such as nitrogen and phosphorus stimulate an explosion in microscopic algae, creating huge “algal blooms”. The algae then die and sink to the bottom, where they decompose. But the same bacteria which decompose the algae also use the sea’s oxygen during the process, leaving an “anoxic” ocean.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/181539/original/file-20170809-11491-y6ke4h.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/181539/original/file-20170809-11491-y6ke4h.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/181539/original/file-20170809-11491-y6ke4h.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=296&fit=crop&dpr=1 600w, https://images.theconversation.com/files/181539/original/file-20170809-11491-y6ke4h.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=296&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/181539/original/file-20170809-11491-y6ke4h.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=296&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/181539/original/file-20170809-11491-y6ke4h.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=372&fit=crop&dpr=1 754w, https://images.theconversation.com/files/181539/original/file-20170809-11491-y6ke4h.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=372&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/181539/original/file-20170809-11491-y6ke4h.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=372&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Gulf of Mexico dead zone, July 2017. The map shows an area nearly 400 miles (643km) across.</span>
<span class="attribution"><a class="source" href="http://www.noaa.gov/media-release/gulf-of-mexico-dead-zone-is-largest-ever-measured">N. Rabalais, LSU/LUMCON</a></span>
</figcaption>
</figure>
<p>Fish and other mobile sea creatures are able to escape the suffocating dead zone. Less lucky however are the sponges, corals, sea squirts and other animals who live their lives fixed in one place on the sea bed. Low oxygen levels place them under great stress and we have seen <a href="https://sanctuaries.noaa.gov/news/jul16/noaa-scientists-report-mass-die-off-of-invertebrates-at-east-flower-garden-bank.html">huge mortalities</a>. Such losses will of course ripple up the food web, creating a negative chain reaction of increasing mortality rates in larger and larger animals.</p>
<p>The “dead zone” has grown this year due to increased rainfall in America’s Midwest washing <a href="http://news.nationalgeographic.com/2017/08/gulf-mexico-hypoxia-water-quality-dead-zone/">ever greater amounts of nutrients into the Mississippi</a>, which ultimately end up in the Gulf. Not only is this a huge conservation issue – the Gulf contains key nursery habitats such as mangrove forests, sea grass beds and coral reefs that benefit adjacent fisheries – but it also has huge consequences for the local fishing economy, particularly the <a href="http://www.pnas.org/content/114/7/1512.abstract">shrimp industry</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/181793/original/file-20170811-13451-1x8g35l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/181793/original/file-20170811-13451-1x8g35l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/181793/original/file-20170811-13451-1x8g35l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=353&fit=crop&dpr=1 600w, https://images.theconversation.com/files/181793/original/file-20170811-13451-1x8g35l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=353&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/181793/original/file-20170811-13451-1x8g35l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=353&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/181793/original/file-20170811-13451-1x8g35l.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=444&fit=crop&dpr=1 754w, https://images.theconversation.com/files/181793/original/file-20170811-13451-1x8g35l.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=444&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/181793/original/file-20170811-13451-1x8g35l.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=444&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The dead zone is bad news for local shrimpers.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/finchlake/5858195835/">finchlake2000</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Steps are under way to slow down the ecological disaster. Some farmers in the Mississippi basin are using large grassy zones along waterways in order to <a href="https://environmentalchange.nd.edu/news-events/news/farmers-reduce-pollution-after-ditching-old-way-of-handling-runoff/">soak up the agricultural fertilisers</a> and filter out many of the nutrients before they make their way down the Mississippi to pollute the Gulf. However, it remains to be seen whether such measures are effective – and US farmers certainly need to greatly reduce the <a href="https://www.theguardian.com/commentisfree/2017/aug/04/meat-industry-gulf-mexico-dead-zones-pollution">nitrogen and phosphates they use</a>.</p>
<p>In the century since Muir’s death, things have sped up. A larger population demands more food which means more deforestation, more farmland and more fertiliser. The increase demand placed on our land is ultimately affecting the marine environment.</p>
<p>These losses are unsustainable. The marine environment is integral for all life on earth, from an ecological and economic point of view. If we keep losing ecosystem services such as coastal nursery habitats and spawning grounds at this current rate, it will not just be an area the size of a state that is a dead zone, but the whole Gulf, or even <a href="https://theconversation.com/ancient-dead-seas-offer-a-stark-warning-for-our-own-near-future-47984">whole oceans</a>.</p><img src="https://counter.theconversation.com/content/82175/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Ian Hendy does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Oxygen-free areas will continue to grow until we stop pumping excess nutrients into the oceans.Ian Hendy, Senior Scientific Officer, Institute of Marine Sciences, University of PortsmouthLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/588522016-07-06T01:05:14Z2016-07-06T01:05:14ZReducing water pollution with microbes and wood chips<figure><img src="https://images.theconversation.com/files/129012/original/image-20160701-18321-znh4zj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Harmful algal bloom caused by nutrient pollution, Assateague island National Seashore, MD</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/usepagov/9324594954/in/album-72157634706332559/">Eric Vance, U.S. EPA/Flickr</a></span></figcaption></figure><p>Beneath fields of corn and soybeans across the U.S. Midwest lies an unseen network of underground pipes. These systems, which are known as <a href="http://www.extension.umn.edu/agriculture/water/planning-a-subsurface-drainage-system/">tile drainage networks</a>, channel excess water out of soil and carry it to lakes, streams and rivers. There are <a href="http://pdf.wri.org/assessing_farm_drainage.pdf">over 38 million acres</a> of tile drainage in the Corn Belt states.</p>
<p>These networks play a vital role in farm production. They allow farmers to drive tractors into fields that would otherwise be too wet and make it possible to plant early in spring. And they boost crop growth and yield by preventing fields from becoming waterlogged. </p>
<p>But drainage systems are also major contributors to water pollution. The water they remove from fields contains nitrogen, which comes both from organic matter in rich Midwestern soil and from fertilizer. This nitrogen over-fertilizes downstream water bodies, causing blooms of algae. When the algae die, bacteria decompose them, using oxygen in the water as fuel. </p>
<p>The result is hypoxic zones, also known as dead zones, where nothing can live. Some of these zones, such as the one that forms in the Gulf of Mexico every year fed by Midwestern farm drainage water, cover thousands of miles.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/129013/original/image-20160701-18334-1wnc55c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/129013/original/image-20160701-18334-1wnc55c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=464&fit=crop&dpr=1 600w, https://images.theconversation.com/files/129013/original/image-20160701-18334-1wnc55c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=464&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/129013/original/image-20160701-18334-1wnc55c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=464&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/129013/original/image-20160701-18334-1wnc55c.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=583&fit=crop&dpr=1 754w, https://images.theconversation.com/files/129013/original/image-20160701-18334-1wnc55c.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=583&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/129013/original/image-20160701-18334-1wnc55c.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=583&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The Gulf of Mexico dead zone forms every summer, fed by drainage from midwestern farms.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Dead_zone_(ecology)#/media/File:Dead_Zone_NASA_NOAA.jpg">NASA/NOAA via Wikipedia</a></span>
</figcaption>
</figure>
<p>Across the Midwest and in many other areas, we need to reduce nitrogen pollution on a very large scale to improve water quality. My research focuses on woodchip bioreactors – simple trenches that can be constructed on farms to clean the water that flows out of tile drains. This is a proven practice that is ready for broad-scale implementation. Nevertheless, there is still great potential to improve how well wood chip bioreactors work, and to convince farmers to use them through additional research and engagement. </p>
<h2>Removing nitrogen from farm runoff</h2>
<p>Researchers studying ways to improve agricultural water quality have <a href="https://store.extension.iastate.edu/Product/Woodchip-Bioreactors-for-Nitrate-in-Agricultural-Drainage">shown</a> that we can use a natural process called denitrification to treat subsurface drainage water on farms. It relies on bacteria found in soil around the world to convert nitrate – the form of nitrogen in farm drainage water – to nitrogen gas, which is environmentally benign and makes up more than three-fourths of the air we breathe. </p>
<p>These bacteria use carbon as a food source. In oxygen-free conditions, such as wetlands or soggy soils, they are fueled by carbon in the surrounding soil, and inhale nitrate while exhaling nitrogen gas. Bioreactors are engineered environments that take advantage of their work on a large scale.</p>
<p>Denitrifying bioreactors on farms are surprisingly simple. To make them we dig trenches between farm fields and the outlets where water flows from tile drains into ditches or streams. We fill them with wood chips, which are colonized by native bacteria from the surrounding soil, and then route water from farm drainage systems through the trenches. The bacteria “eat” the carbon in the wood chips, “inhale” the nitrate in the water, and “exhale” nitrogen gas. In the process, they reduce nitrogen pollution in water flowing off of the farm by anywhere from 15 percent to over 90 percent.</p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/124405/original/image-20160529-879-7xejt3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124405/original/image-20160529-879-7xejt3.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=465&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124405/original/image-20160529-879-7xejt3.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=465&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124405/original/image-20160529-879-7xejt3.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=465&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124405/original/image-20160529-879-7xejt3.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=584&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124405/original/image-20160529-879-7xejt3.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=584&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124405/original/image-20160529-879-7xejt3.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=584&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A denitrifying woodchip bioreactor removing nitrate from a tile-drained corn field.</span>
<span class="attribution"><span class="source">Christianson and Helmers/Iowa State Extension</span></span>
</figcaption>
</figure>
<p>Although denitrifying bioreactors are relatively new, they have moved beyond proof of concept. A new <a href="https://dl.sciencesocieties.org/publications/jeq/tocs/45/3#h1-SPECIAL%20SECTION:%20MOVING%20DENITRIFYING%20BIOREACTORS%20BEYOND%20PROOF%20OF%20CONCEPT">special collection of papers in the Journal of Environmental Quality</a>, which I co-edited with <a href="http://sci.waikato.ac.nz/about-us/people/schipper">Dr. Louis Schipper</a> of the <a href="http://www.waikato.ac.nz/">University of Waikato</a> in New Zealand, demonstrates that these systems can now be considered an effective tool to reduce pollution in nitrate-laden waters. Researchers are using these systems in an expanding range of locations, applications, and environmental conditions.</p>
<h2>Making bioreactors work for farmers</h2>
<p>Woodchip bioreactors can be installed without requiring farmers to take land out of production, and require very little annual maintenance. These are important selling points for farmers. The Clean Water Act <a href="http://ehp.niehs.nih.gov/122-a304/">does not regulate</a> nitrogen pollution from diffuse agricultural sources such as farm runoff, but states across the Midwest are working with federal regulators to set <a href="https://www.epa.gov/nutrient-policy-data/state-development-numeric-criteria-nitrogen-and-phosphorus-pollution">targets for reducing nitrogen pollution</a>. They also are developing <a href="https://www.epa.gov/ms-htf/hypoxia-task-force-nutrient-reduction-strategies">water quality strategies</a> that call for installing tens of thousands of denitrifying bioreactors to help reach those targets. </p>
<p>So far, wood chips have proven to be the most practical bioreactor fill. Research at the lab scale has also analyzed the idea of using farm residues such as corn cobs instead. In laboratory studies, such <a href="http://dx.doi.org/10.2134/jeq2015.07.0407">agricultural residues consistently provide much higher nitrate removal rates than wood chips</a>. However, they need to be replaced more frequently than wood chips, which have an estimated design life of 10 years in a bioreactor. </p>
<p>Laboratory studies have also helped us understand how <a href="http://dx.doi.org/10.2134/jeq2015.07.0399">other factors</a> influence nitrate removal in bioreactors, including water temperature and the length of time that water remains inside the bioreactor – which, in turn, depends on the flow rate and the size of the bioreactor. Another challenge is that bioreactors work best in late summer, when drainage flow rates are low and the water flowing from fields is warm, but most nitrogen flows from fields in drainage water in spring, when conditions are cool and wet. Researchers are working to design bioreactors that can overcome this disconnect. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/124406/original/image-20160529-859-la586a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/124406/original/image-20160529-859-la586a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=439&fit=crop&dpr=1 600w, https://images.theconversation.com/files/124406/original/image-20160529-859-la586a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=439&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/124406/original/image-20160529-859-la586a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=439&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/124406/original/image-20160529-859-la586a.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=552&fit=crop&dpr=1 754w, https://images.theconversation.com/files/124406/original/image-20160529-859-la586a.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=552&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/124406/original/image-20160529-859-la586a.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=552&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Installing a denitrifying woodchip bioreactor.</span>
<span class="attribution"><span class="source">L. Christianson /Iowa Soybean Association Environmental Programs and Services</span></span>
</figcaption>
</figure>
<p>We have also carried out tests to see whether bioreactors can treat <a href="http://dx.doi.org/10.2134/jeq2015.05.0242">aquaculture wastewater</a>, which typically contains much higher levels of nitrate and other water pollutants than tile drainage water. Our study showed that bioreactors could be a viable low-cost water treatment option for fish farms. </p>
<p>And researchers from New Zealand recently showed that denitrifying bioreactors may be an effective option for treating some small sources of municipal wastewater. <a href="http://dx.doi.org/10.2134/jeq2015.06.0326">Their work</a> provided the first indication that woodchip bioreactors may be able to remove microbial contaminants like E.coli and viruses, which can be hazardous to human health, from water. The exact process by which the E.coli and viruses were removed is not yet known. </p>
<p>One difficult challenge in designing denitrifying bioreactors is testing novel designs at the field scale. We need to build and test large bioreactors so that we can provide useful information to farmers, landowners, crop advisors, drainage contractors, conservation staff, and state and federal agencies. They want to know practical facts, such as how long the wood chips last (approximately 7-15 years), how much it costs to install a field-scale bioreactor ($8,000-$12,000), and whether bioreactors back up water in tile drainage systems (no). To refine what we know, we plan to continue installing full-size bioreactors either on research farms or by collaborating with private farmers who want to be at the cutting edge of water-quality solutions. </p>
<p>We all play a role in agriculture because we all eat, and at the same time, we all need clean water. Simple technologies like woodchip bioreactors can help meet both goals by helping farmers maintain good drainage and providing cleaner water downstream.</p><img src="https://counter.theconversation.com/content/58852/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Laura Christianson receives funding from the Illinois Nutrient Research and Education Council. </span></em></p>Excess nutrients from farm fields cause widespread water pollution across the U.S. Bioreactors – essentially, ditches filled with wood chips – are emerging as a way to reduce nutrient pollution.Laura Christianson, Research Assistant Professor of Crop Sciences, University of Illinois at Urbana-ChampaignLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/586122016-06-13T09:55:03Z2016-06-13T09:55:03ZClimate change could alter the chemistry of deepwater lakes and harm ecosystems<figure><img src="https://images.theconversation.com/files/125930/original/image-20160609-7069-1bwtee4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Climate change is warming Lake Tahoe and could alter its chemistry in harmful ways</span> <span class="attribution"><a class="source" href="http://www.shutterstock.com/cat.mhtml?searchterm=lake%20tahoe&keyword_search=1&page=1&inline=335212964">www.shutterstock.com</a></span></figcaption></figure><p>In an age of rapid global population growth, demand for safe, clean water is constantly increasing. In 2010 the United States alone used <a href="http://pubs.usgs.gov/circ/1405/">355 billion gallons of water per day</a>. Most of the available fresh water on Earth’s surface is found in lakes, streams and reservoirs, so these water bodies are critical resources. </p>
<p>As a limnologist, I study lakes and other inland waters. This work is challenging and interesting because every lake is an ecosystem that is biologically, chemically and physically unique. They also are extremely sensitive to changes in regional and global weather and long-term climate patterns. </p>
<p>For these reasons, lakes are often called <a href="http://dx.doi.org/10.4319/lo.2009.54.6_part_2.2273">“sentinels of change.”</a> Like the figurative canary in the coal mine, lakes may experience change to their ecosystem dynamics before we start to see shifts in the greater watersheds around them.</p>
<p>In a <a href="http://dx.doi.org/10.1002/lno.10228">study</a> I recently co-authored with <a href="http://research.engineering.ucdavis.edu/edl/people/">Goloka Behari Sahoo, S. Geoffrey Schladow, John Reuter</a>, <a href="http://www.hydroikos.com/resumes.htm">Robert Coats</a> and <a href="https://profile.usgs.gov/mddettin">Michael Dettinger</a>, we projected that future climate change scenarios will significantly alter natural mixing processes in Lake Tahoe in the Sierra Nevada range that are critical to the health of the lake’s ecosystem. This could potentially create a condition that we termed <a href="http://dx.doi.org/10.1002/lno.10228">“climatic eutrophication.”</a></p>
<p>While many groups have studied the long-term impact of climate change on lakes, this process can now be added to the growing list of drivers of eutrophication. This is a potentially damaging phenomenon that could affect a number of vital deep-water lakes around the world, degrading water quality and harming fish populations.</p>
<h2>The impact of too many nutrients</h2>
<p>Eutrophication is a condition that occurs when lakes and reservoirs become overfertilized. <a href="https://www.epa.gov/nutrientpollution/problem">Cultural eutrophication</a> is a well-understood process in which lake and reservoir ecosystems become overloaded with chemical nutrients, mainly nitrogen and phosphorus. These nutrients come from human activities, including fertilizer runoff from farms and releases from sewage systems and water treatment plants. Natural weathering processes, atmospheric deposition of air pollutants, and erosion also transport nutrients that are already present in the watershed into the water supply. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/125948/original/image-20160609-7090-1rztzy3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/125948/original/image-20160609-7090-1rztzy3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/125948/original/image-20160609-7090-1rztzy3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/125948/original/image-20160609-7090-1rztzy3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/125948/original/image-20160609-7090-1rztzy3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/125948/original/image-20160609-7090-1rztzy3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/125948/original/image-20160609-7090-1rztzy3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=500&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A creek in Indiana that has been straightened and deepened to drain farm fields. Agricultural drainage systems can carry large quantities of excess nutrients into rivers, lakes and bays.</span>
<span class="attribution"><a class="source" href="http://water.usgs.gov/edu/photos-waterquality.html">U.S. Geological Survey</a></span>
</figcaption>
</figure>
<p>In water bodies, these heavy nutrient loads fertilize algae, causing surface algal blooms. When the algae die, they sink and are broken down as they decompose. This decomposition process consumes dissolved oxygen in the water. As oxygen levels become depleted, hypoxic (dead) zones develop in the bottom waters where oxygen levels are too low to support life. Dead zones harm fisheries and tourism, and algal blooms can contaminate drinking water.</p>
<p>Over the past several decades, state and federal regulators have developed <a href="https://www.epa.gov/nutrient-policy-data/what-epa-doing">many initiatives</a> to eliminate or reduce nutrient sources. In some cases, such as Seattle’s <a href="http://www.kingcounty.gov/services/environment/water-and-land/lakes/lakes-of-king-county/lake-washington/lake-washington-story.aspx">Lake Washington</a>, water quality has improved through management. In other, larger watersheds – notably, the <a href="https://www.epa.gov/nutrient-policy-data/great-lakes">Great Lakes</a> – nutrient pollution is still a major problem. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/125561/original/image-20160607-15038-14lu3id.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/125561/original/image-20160607-15038-14lu3id.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/125561/original/image-20160607-15038-14lu3id.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/125561/original/image-20160607-15038-14lu3id.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/125561/original/image-20160607-15038-14lu3id.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/125561/original/image-20160607-15038-14lu3id.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/125561/original/image-20160607-15038-14lu3id.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Harmful algal bloom in Lake Erie, 2009.</span>
<span class="attribution"><a class="source" href="https://www.flickr.com/photos/noaa_glerl/4075261427/in/photolist-7d7Mf4-cMtuny-azi1jJ-9UhCu2-7dbGds-q3zGcD-gdkVHr-ejuU6o-7d7PCg-ejpakn-79HVaM-ejpb8M-oinCax-8ut629-cWdBbw-ejnKgt-ejuU91-ejpaaa-8xRCyq-adrBYv-fJjbTQ-p5BgW9-ejuTfh-d6uvAu-d6uuJ7-d6uvad-aEEoqe-fubE8i-g8WAAh-fuqYFG-g8X5Xg-aqHJaG-cEKfSJ-p5Bgvj-fubE9c-g8X5Sr-aqF3iT-pn3zZw-aqF32R-pmMY3t-azKykg-p5zeBf-7dbEmf-aqHJgo-ejpbok-g8WAJo-p5Am64-fxKsXG-z5Be3B-p5zgnj">T. Archer, NOAA/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Climate change and mixing in lakes</h2>
<p>As anyone who has swum in a lake knows, the water is typically warmest on the surface where the sun shines on it. Cold water is denser than warmer water, so it sinks. For much of the year, deep lakes will remain stratified (separated into layers).</p>
<p>In fall and late winter, large storms disrupt natural stratification and cause lake waters to overturn. This mixes surface waters down into the lake’s depths and brings deep water up to the surface, where it can absorb oxygen from the atmosphere. This process, which transfers dissolved oxygen from the surface to the lake bottom, is critical for an ecosystem’s health. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/125950/original/image-20160609-7049-1wwhs2t.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/125950/original/image-20160609-7049-1wwhs2t.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=200&fit=crop&dpr=1 600w, https://images.theconversation.com/files/125950/original/image-20160609-7049-1wwhs2t.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=200&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/125950/original/image-20160609-7049-1wwhs2t.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=200&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/125950/original/image-20160609-7049-1wwhs2t.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=251&fit=crop&dpr=1 754w, https://images.theconversation.com/files/125950/original/image-20160609-7049-1wwhs2t.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=251&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/125950/original/image-20160609-7049-1wwhs2t.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=251&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Seasonal stratification in temperate lakes. The thermocline is a layer that separates warm water from colder deep water.</span>
<span class="attribution"><a class="source" href="https://en.wikipedia.org/wiki/Lake_ecosystem#/media/File:LSE_Stratification.png">Hydrated/Wikipedia</a></span>
</figcaption>
</figure>
<p>But our study showed that surface warming in Lake Tahoe could cause climatic eutrophication by reducing or even ending mixing, thus interrupting the vertical movement of dissolved oxygen from the lake’s surface to the lake bed. </p>
<p>Scientists, spearheaded by the University of California - Davis, have been monitoring conditions at Lake Tahoe for nearly 50 years, so we have good records of short- and long-term changes in water temperatures and quality. Since 1968, the average temperatures of the lake’s surface waters (down to a depth of 80-120 feet) have increased by nearly 0.5 degrees Celsius. That change has increased the lake’s stability – a measurement of how resistant it is to overturning – enough to reduce the probability that surface waters will mix all the way to the lake bottom.</p>
<p>To model possible future conditions, we estimated Lake Tahoe’s annual stability by combining a lake hydrodynamic model – representing how water is moved around the lake – with two different greenhouse gas emission scenarios <a href="http://dx.doi.org/10.1007/s10584-012-0501-x">published by the Intergovernmental Panel on Climate Change</a>. In one scenario, emissions increased rapidly throughout this century; in the other, emissions leveled off by the year 2100. </p>
<p>Under both scenarios, meteorological conditions influencing the lake are projected to change. Notably, wind speeds would <a href="http://dx.doi.org/10.1007/s10584-012-0600-8">decrease by 7-10 percent, and air temperatures would increase by 2.5-4 degrees Celsius</a>. These warmer, less windy conditions across the lake will extend and magnify the warming and stratification trends that we are already seeing.</p>
<p>As the lake remains stratified for longer periods each year and less overturning occurs, dissolved oxygen levels at the bottom will decline. Under these conditions, nutrients stored in the lake bed will be released to the water through chemical reactions that occur in low-oxygen environments. This new source of nutrients, known as internal loading, will further contribute to the process of climatic eutrophication.</p>
<p>Although all lakes are unique ecosystems, this process could also occur in other deep-lake settings around the world, such as Japan’s <a href="http://www.lbm.go.jp/english/facts/">Lake Biwa</a> or <a href="http://whc.unesco.org/en/list/754">Lake Baikal</a> in southeastern Siberia. Climate change is already shortening the periods each year when many temperate and polar lakes are covered with ice. As water temperatures rise in the upper layers of deep lakes, they will remain stratified for more of the year and will be less subject to mixing. Less dissolved oxygen will be returned to deep waters, which will stress fish populations. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/125951/original/image-20160609-7059-vtqr6x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/125951/original/image-20160609-7059-vtqr6x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/125951/original/image-20160609-7059-vtqr6x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/125951/original/image-20160609-7059-vtqr6x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/125951/original/image-20160609-7059-vtqr6x.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/125951/original/image-20160609-7059-vtqr6x.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/125951/original/image-20160609-7059-vtqr6x.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Ice melting on Lake Baikal in Siberia, which contains 20 percent of the fresh water on Earth’s surface.</span>
<span class="attribution"><a class="source" href="http://visibleearth.nasa.gov/view.php?id=83646">NASA Earth Observatory</a></span>
</figcaption>
</figure>
<p>And unlike cultural eutrophication, climatic eutrophication could affect entire watersheds or regions, since it is driven by climatic influences rather than by discharges of nutrients into a lake from farms or cities.</p>
<p>Climatic eutrophication has serious implications for long-term water supplies and aquatic ecosystem health around the world. To recognize and track it, we need to identify lakes in North America and around the world that could be at high risk. </p>
<p>In areas where scientists and regulators are working to reduce conventional eutrophication, these experts will also need to factor the possibility of climate-forced eutrophication into their strategies. The first step is to support more monitoring of lakes’ physics and chemistry so that we can recognize, track and predict climatic eutrophication of our lakes and reservoirs.</p><img src="https://counter.theconversation.com/content/58612/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Alexander L. Forrest does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Lakes contain most of the fresh water on Earth’s surface. Recent research at Lake Tahoe in the Sierra Nevada mountains shows that climate change could alter lake chemistry, threatening these sources.Alexander L. Forrest, Assistant Professor of Environmental Engineering, University of California, DavisLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/63102012-04-18T04:18:24Z2012-04-18T04:18:24ZFarms versus nature: how do we decide what to protect?<figure><img src="https://images.theconversation.com/files/9662/original/kyk945n2-1334560062.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Our thinly spread efforts to prop up the environment are failing and it is time for tough decisions about what we can realistically preserve.</span> <span class="attribution"><span class="source">Flickr/rexboggs5</span></span></figcaption></figure><p>Australian farmers take pride in their efficient and productive farming systems, competing in the global economy and without many of the large subsidies given to their counterparts in Europe and North America. There are many agricultural success stories in Australia - such as reducing soil erosion through conservation tillage - but major environmental problems have also emerged.</p>
<p>These include increased salinity, soil acidification and, increasingly, loss of sediment and nutrients which cause <a href="http://www.soe.wa.gov.au/report/inland-waters/eutrophication.html">eutrophication of waterways</a> (a harmful excess of certain nutrients, commonly nitrogen and phosphorous) and algal blooms. The <a href="https://theconversation.com/great-barrier-reef-dying-beneath-its-crown-of-thorns-6383">ongoing extermination of coral</a> on the Great Barrier Reef - down from covering 50% of the reef in the 1960s to 16% now - is largely caused by such factors.</p>
<p>Billions of dollars have been spent to protect the environment. This funding supports programs such as <a href="http://www.landcareonline.com.au/">Landcare</a>, the <a href="http://www.nht.gov.au/">Natural Heritage Trust</a>, the National Action Plan for Salinity and Water Quality and its successor, the <a href="http://www.nrm.gov.au/">Caring for Our Country Program</a>. Unfortunately, evaluation has shown that whilst many programs have been successful at raising landholder awareness, there is almost no evidence that they have prevented, reversed, or even stabilised the decline of our environment. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/9659/original/x8mzq7zp-1334558257.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/9659/original/x8mzq7zp-1334558257.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/9659/original/x8mzq7zp-1334558257.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/9659/original/x8mzq7zp-1334558257.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/9659/original/x8mzq7zp-1334558257.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/9659/original/x8mzq7zp-1334558257.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/9659/original/x8mzq7zp-1334558257.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In bloom: algae thrives on our inability to contain the fertilisers used in farming.</span>
<span class="attribution"><span class="source">Flickr/suavehouse113</span></span>
</figcaption>
</figure>
<p>There are many reasons for this failure, but among the most important is that funding is poorly targeted and spread very thinly (the “Vegemite” approach) across vast areas of the landscape.</p>
<p>Governments and agricultural industries alike are understandably attracted to “soft” approaches, such as providing information and giving small, temporary incentives. Most Australian agri-environmental programs have been based on the following assumptions: </p>
<ul>
<li><p>Participation of landholders somehow equates to improving the environment.</p></li>
<li><p>Voluntary adoption of “best-management practices” is highly effective.</p></li>
<li><p>Voluntary participation of landholders in programs will be sufficient. In many circumstances this is unlikely to be the case.</p></li>
</ul>
<p>The failure of such programs and the smallness of environmental funding pose a large dilemma for governments and the broader community. The reality is that not everything can be protected; choosing to fund protection of one area means abandoning another. And is government prioritising the right areas?</p>
<p>In short, choosing a much smaller number of environmental projects and funding them enough to actually succeed would deliver much greater environmental value for public money. It would also reduce constant criticism that government programs aren’t doing enough.</p>
<p>Facing unpleasant realities initially sparks denial, anger, and despair. However, it is important to understand and face ugly truths, so that we can change and start actually restoring the environment. A team working with the <a href="http://www.futurefarmonline.com.au/">Future Farm Industries Co-operative Research Centre</a> have designed a system called <a href="Investment%20Framework%20for%20Environmental%20Resources">Investment Framework for Environmental Resources</a> (INFFER). It embeds economics into environmental decision-making, making it possible to integrate available science (biophysical, ecological and social) with local information to help make more informed decisions about environmental investment. </p>
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<figcaption>
<span class="caption">A resident of Raymond Island in the Gippsland Lakes. An estimated 80% of Australia’s koala habitat has been cleared since European settlement.</span>
<span class="attribution"><span class="source">Flickr/platypusbloke</span></span>
</figcaption>
</figure>
<p>INFFER has been applied to the Gippsland Lakes, which are threatened by excessive nutrient losses and algal blooms. The Gippsland Lakes Taskforce set an environmental target of 40% phosphorus reduction. INFFER’s <a href="http://www.inffer.org/agriculture-and-environment-trade-offs-in-the-gippsland-lakes/">Gippsland Lakes analysis</a> shows that achieving this target requires close to $1 billion funding over 25 years. The allocated funding (approximately $35 million to date) falls drastically short.</p>
<p>This realistic level of funding is very off-putting. But compounding it, the scale of land management changes, including retiring land from agricultural use, is likely to be highly unpopular. The political difficulties, high cost and scale of change mean achieving the 40% phosphorus reduction target is also not cost-effective.</p>
<p>A lower environmental target of 20% would not achieve the same degree of environmental improvement (although it would still be expected to reduce the frequency of algal blooms) but would be much more cost-effective. The funding required to achieve a 20% phosphorus reduction target is about $80 million.</p>
<p>Faced with the reality that not all environmental assets can be protected, difficult decisions need to be made based on the value of the environmental asset, the threats faced, the environmental goal required, the feasibility of protection and the risks involved.</p>
<p>Although INFFER highlights some politically difficult challenges, it also provides a huge opportunity for more informed environmental decision-making and investment. Sciences and economics are vital to provide evidence-based decision-making. Tools such as INFFER provide a way to integrate the factors needed to make informed decisions. </p>
<p>“Win-win” outcomes for agriculture and the environment are not always possible: discussion about the trade-offs is required. Conflicts between maintaining agricultural production and protecting the environment occur in all parts of Australia, and indeed globally. </p>
<p>If we are to protect important national assets such as the Great Barrier Reef and the Coorong/Lower Lakes on the Murray River, we need to have much more informed policy discussion and analysis. Assessment of the costs and feasibility of achieving sufficiently large and measurable environmental outcomes should be mandatory requirements for the large sums of public money being spent. And we also need informed discussion and policy analysis about where we should maintain agricultural production and trade off environmental values - a situation currently happening by default in many areas.</p>
<p><em>These views are personal and do not necessarily reflect the views of the Victorian government.</em></p>
<p><em>Comments welcome below.</em></p><img src="https://counter.theconversation.com/content/6310/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Anna Roberts currently receives funding from the Department of Primary Industries and the Department of Sustainability and Environment. In addition the Investment Framework for Environmental Resources group have received funding from the Future Farm Industries Co-operative Research Centre, the Commonwealth Environmental Research Fund and the Australian Research Council. Anna works for the Department of Primary Industries as a Senior Research Scientist and has an Adjunct position at La Trobe University. The views expressed are personal and do not reflect the views of the Victorian government.</span></em></p>Australian farmers take pride in their efficient and productive farming systems, competing in the global economy and without many of the large subsidies given to their counterparts in Europe and North…Anna Roberts, Adjunct Professor, La Trobe UniversityLicensed as Creative Commons – attribution, no derivatives.