tag:theconversation.com,2011:/us/topics/fish-conservation-74943/articlesFish conservation – The Conversation2022-12-15T19:07:19Ztag:theconversation.com,2011:article/1959662022-12-15T19:07:19Z2022-12-15T19:07:19ZAboriginal people have spent centuries building in the Darling River. Now there are plans to demolish these important structures<figure><img src="https://images.theconversation.com/files/501221/original/file-20221215-14-ap036o.jpeg?ixlib=rb-1.1.0&rect=26%2C3%2C2525%2C1695&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Deal Lewis/AAP</span></span></figcaption></figure><p>Apart from managing the land, Indigenous people have also managed waterways, including the Murray River and the Darling/Baaka River, for thousands of years. </p>
<p>Like many Indigenous <a href="https://www.budjbim.com.au/?gclid=EAIaIQobChMInLvSl_v0-wIVRZ_CCh0RsgsEEAAYASAAEgIz8_D_BwE">peoples of Australia</a>, the Barkandji people of the Baaka manipulated and enhanced the river and floodplain ecosystems of their country.</p>
<p>Now, our <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/arco.5279">research</a> on stone, wood and earthen fish traps and fish weirs on the Baaka and its floodplains reveals how these aquatic resources were managed, grown and stored by the Barkandji.</p>
<p>These structures, and the cultural practices that sustain them, are still significant to the Barkandji people – but they’ve been severely affected by colonisation, and remain at risk from government commitments to irrigation. </p>
<h2>Reconstructing the Baaka’s Aboriginal past</h2>
<p>To study the structures in the Baaka we relied on archaeological methods, Barkandji knowledge and oral history, and written accounts from early settlers and explorers. </p>
<p>We found most of the wooden or earthen fish traps on the Baaka’s floodplains have not endured and aren’t archaeologically visible. There are, however, some existing and remnant stone traps – which were once common along the 1,200km channel. </p>
<p>These structures were encountered by explorers, ship pilots, graziers and other settlers who travelled along the Baaka between Wentworth and Bourke.</p>
<h2>The first threat to the traps were paddle steamers</h2>
<p>The first paddle steamer travelled in 1861 up the Baaka from Wentworth at the Murray-Darling junction to Brewarrina on the Barwon River. It was piloted by Captain <a href="https://en.wikipedia.org/wiki/William_Randell">William Randell</a>, and was unable to pass over the fish traps due to a lack of draught over the rocks. </p>
<p>This voyage initiated the famous paddle steamer trade that continued into the 1940s. Rocks in the river often stopped these vessels from navigating at low water levels, and they occasionally even sank. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=374&fit=crop&dpr=1 600w, https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=374&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=374&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=470&fit=crop&dpr=1 754w, https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=470&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/501215/original/file-20221215-23-lu4eme.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=470&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 photo published in 1926 of the ‘P.S. Colonel’ and barges drifting downstream at Christmas Rocks.</span>
<span class="attribution"><span class="source">PRG 1258/2/2260 Godson Collection, State Library South Australia</span></span>
</figcaption>
</figure>
<p>This prompted government-resourced teams to force a passage through by blasting the rocks with dynamite. This blasted rock can still be seen at some outcrops, including areas that have the remains of fish traps or are known to have once had them. Indigenous people built new traps in these areas, often using the blasted rock.</p>
<p>During the 20th century, a series of low-level weirs were built at the small towns along the river to secure water supplies. Settlers sought the same river features to build weirs that Indigenous people did when choosing sites for stone fish traps, so many weirs were built on outcropping rock. </p>
<p>These weirs tended to have loose boulders on the downstream side to hold the weir wall in place. At Wilcannia, the Indigenous workers who carted and placed the rocks at the weir later made them into stone fish traps, which are still used today. </p>
<p>They are made in steps going up the weir wall, helping fish climb the wall like a modern fish ladder.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/500959/original/file-20221214-18-u73s9p.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">The Wilcannia weir stone fish traps are still used by young Barkandji people.</span>
<span class="attribution"><span class="source">Sarah Martin</span></span>
</figcaption>
</figure>
<h2>Taking too much water for irrigation</h2>
<p>During the last two decades an increasing amount of water has been removed for large-scale irrigation from the Baaka and its northern tributaries. By 2019, excessive water extraction had virtually dried the Baaka and Barwon rivers from Wentworth to Collarenebri – a route more than 2,000km long. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/excessive-water-extractions-not-climate-change-are-most-to-blame-for-the-darling-river-drying-192621">Excessive water extractions, not climate change, are most to blame for the Darling River drying</a>
</strong>
</em>
</p>
<hr>
<p>The mass fish kills at Menindee in 2018–2019 showed the devastating effects of removing so many of the <a href="https://theconversation.com/the-murray-darling-basin-plan-is-not-delivering-theres-no-more-time-to-waste-91076">small to medium flows</a> that kept the ecosystem functioning. </p>
<p>This extended dry river resulted in the near extinction of many species, including river snails, mussels, catfish and silver bream. Also, without water in the river, the Barkandji could not use their fish traps or pass along knowledge of their history and significance.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A dry, rocky riverbed stretches out." src="https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/501214/original/file-20221215-19-lu4eme.jpeg?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"></a>
<figcaption>
<span class="caption">The Baaka dried up due to excessive water extraction. Pictured here is an area at Wilcannia in 2019.</span>
<span class="attribution"><span class="source">Sarah Martin</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The New South Wales government’s response to the crisis now presents a new threat to the fragile fish traps. In 2019 the government <a href="https://legislation.nsw.gov.au/view/html/inforce/current/act-2019-016#">passed legislation</a> to fast-track new water infrastructure, despite <a href="https://www.science.org.au/supporting-science/science-policy-and-sector-analysis/reports-and-publications/fish-kills-report">strong evidence</a> it needs to reduce the amount of water allocated to irrigation. </p>
<p>The legislation enables new dams and new (higher) weirs. The old weir at Wilcannia, which has been used by Indigenous people as a series of fish traps for at least 60 years, will be partly demolished and will no longer function as a fish trap. This is despite the Indigenous community’s strong opposition. </p>
<p>The legislation also allows for the “re-establishment of natural rock weirs on the Darling River between Bourke and its junction with the Murray River”. This suggests all the rock outcrops in the Darling Baaka were originally weirs that stretched like a wall across the river and held water back (before being blasted to allow paddle steamers to pass).</p>
<p>But our field survey coupled with historical material indicates most rock outcrops were originally uneven, with openings and numerous loose rocks. This allowed water to flow through and over the rocks at different river heights, enabling the fish traps to work and helping sustain the ecosystem.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/bushfire-arson-prevention-is-the-cure-11506">Bushfire arson: prevention is the cure</a>
</strong>
</em>
</p>
<hr>
<h2>How should the river be managed?</h2>
<p>Fish traps set by Aboriginal people along the Baaka offer valuable insight into how this precious body of water could be managed. The first thing is the river needs its “low and medium flows” protected.</p>
<p>Historically, Aboriginal people have held ceremonies (and to some extent still do) to mark mass migrations of fish such as golden perch and silver bream that travel upstream to spawn. These fish have to be able to travel up and down the river unimpeded. As seen at the Wilcannia weir, fish traps assist with this.</p>
<p>There are also several benefits from water flowing over and through fish trap stone walls. The walls increase flow turbulence, reduce silting, improve water quality and are “keyed” to let small fish through. They also provide a rocky habitat that effectively forms “multi-storey apartments” for invertebrates such as yabbies and river snails.</p>
<p>Stone fish traps are also often found in association with shallow aquifer springs, with one recorded trap built around a spring. This is evidence of fish management; the fresh spring water attracts fish and acts as a refuge during drought.</p>
<p>Local Indigenous people also understand the necessity of regularly filling floodplain lakes, swamps and billabongs. They previously enhanced these water bodies by using temporary wooden and earthen weirs – providing fish reserves, fish nurseries and rich and diverse habitats for aquatic life.</p>
<p>These structures kept aquatic plants and animals safe to seed the river with life when floods came down after dry periods. They held water to replenish the shallow aquifers that create springs and soaks in the river.</p>
<p>Water managers have so far largely ignored the potential for Indigenous knowledge to facilitate the sustainable management of the Baaka. Yet Indigenous people living along the Baaka have known about how its water moves long before scientists did.</p>
<p>The NSW government’s proposed infrastructure will not only endanger the remnants of culturally significant fish trap structures, but also impact the river’s ecology. Unless Indigenous people’s experience and knowledge are taken seriously, the Baaka and its precious resources may be depleted beyond the point of saving.</p>
<hr>
<p><em>Acknowledgment: we would like to thank our colleague Sarah Martin, who led the research paper this article is based on, and whose contributions were invaluable in gathering these findings.</em></p>
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<p class="fine-print"><em><span>Michael Westaway receives funding from the Australian Research Council. </span></em></p><p class="fine-print"><em><span>Sue Jackson receives funding from the Australian Research Council and the Commonwealth Government's Murray Darling Basin Water and Environment Program. Sue is a member of the Murray Darling Basin Authority's scientific advisory committee.</span></em></p><p class="fine-print"><em><span>Badger Bates 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>Indigenous engineering and care for Country points to a better way to manage the Baaka.Michael Westaway, Australian Research Council Future Fellow, Archaeology, School of Social Science, The University of QueenslandBadger Bates, Indigenous knowledge holder, Indigenous KnowledgeSue Jackson, Professor, Australian Rivers Institute, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1879282022-09-28T20:59:05Z2022-09-28T20:59:05ZFrom fertiliser to phantom: DNA cracks a century-old mystery about New Zealand’s only extinct freshwater fish<figure><img src="https://images.theconversation.com/files/478543/original/file-20220810-13286-jwchpp.jpeg?ixlib=rb-1.1.0&rect=120%2C74%2C3627%2C1589&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The upokororo, or New Zealand grayling (_Prototroctes oxyrhynchus_)</span> <span class="attribution"><span class="source">Te Papa CC BYNC-ND 4.0</span>, <span class="license">Author provided</span></span></figcaption></figure><p>In 1923, Te Rangi Hīroa (Sir Peter Buck) documented the <a href="https://www.nzgeo.com/stories/out-of-the-frying-pan-into-oblivion/">last confirmed capture</a> of a special fish – the upokororo or New Zealand grayling.</p>
<p>More than two decades later, the upokororo received full governmental protection, but it was too late. No further sightings were ever confirmed. In 1986, the upokororo was <a href="https://www.iucnredlist.org/species/18384/20887241">officially listed as extinct</a>.</p>
<p>The upokororo disappeared so quickly that it’s mostly unknown to Western science.
But almost a century after the last living upokororo was seen, we are now using ancient DNA to finally provide some answers. </p>
<p>Our <a href="https://academic.oup.com/zoolinnean/advance-article/doi/10.1093/zoolinnean/zlac077/6726151?login=false">research reveals</a> the upokororo’s ancient origins, going back 15 to 23 million years, and a link to its Australian cousins. </p>
<h2>From fertiliser to phantom</h2>
<p>Historical accounts show the upokororo was once very common in rivers across the country. In the 1800s, cartloads were caught and traded for use as fertiliser and food. </p>
<p>But then it disappeared, likely as a result of a combination of factors – pollution, overfishing, disease and predation by introduced trout.</p>
<figure class="align-center ">
<img alt="A historic image showing men catching fish." src="https://images.theconversation.com/files/478709/original/file-20220811-17-kjg38d.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/478709/original/file-20220811-17-kjg38d.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=454&fit=crop&dpr=1 600w, https://images.theconversation.com/files/478709/original/file-20220811-17-kjg38d.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=454&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/478709/original/file-20220811-17-kjg38d.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=454&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/478709/original/file-20220811-17-kjg38d.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=571&fit=crop&dpr=1 754w, https://images.theconversation.com/files/478709/original/file-20220811-17-kjg38d.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=571&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/478709/original/file-20220811-17-kjg38d.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=571&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">A funnel-shaped net is set to capture upokororo in the Waiapu River.</span>
<span class="attribution"><span class="source">Alexander Turnball Library CC BY-NC 4.0</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Despite its abundance in the past, only a small handful of preserved upokororo still exist in museums today. This is one reason we know so little about this curious fish. </p>
<p>A second reason is that many of these specimens have been treated with formaldehyde, a chemical that preserves the form of the fish but plays havoc with their DNA.</p>
<h2>Fishy frontiers</h2>
<p>The DNA in specimens “fixed” with chemicals like formaldehyde gets broken up into small pieces and stuck together. Over time, the DNA becomes more and more damaged. </p>
<p>This is a big challenge for researchers who want to study species like the upokororo and a major reason why extinct fish are understudied compared to other extinct species.</p>
<figure class="align-center ">
<img alt="A formalin-fixed specimen fo a New Zealand grayling." src="https://images.theconversation.com/files/478706/original/file-20220811-14-u1lvb6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/478706/original/file-20220811-14-u1lvb6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=398&fit=crop&dpr=1 600w, https://images.theconversation.com/files/478706/original/file-20220811-14-u1lvb6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=398&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/478706/original/file-20220811-14-u1lvb6.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=398&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/478706/original/file-20220811-14-u1lvb6.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=500&fit=crop&dpr=1 754w, https://images.theconversation.com/files/478706/original/file-20220811-14-u1lvb6.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=500&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/478706/original/file-20220811-14-u1lvb6.jpeg?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">An example of a formalin-fixed New Zealand grayling, caught in the Clutha River (1874).</span>
<span class="attribution"><span class="source">Otago Museum CC BY 4.0</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Fortunately, <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/1755-0998.13505">new methods</a> have recently been developed that help to isolate and analyse small damaged fragments of DNA. This means genetic analysis of many “wet preserved” specimens like those of the upokororo is now possible for the first time. </p>
<p>Such genetic information can provide new insights into the origin and identity of extinct species.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-did-ancient-moa-survive-the-ice-age-and-what-can-they-teach-us-about-modern-climate-change-183350">How did ancient moa survive the ice age – and what can they teach us about modern climate change?</a>
</strong>
</em>
</p>
<hr>
<h2>Whakapapa of the upokororo</h2>
<p>Based on the general appearance of the upokororo, scientists have usually considered it to be a close relative of the Australian grayling. The Australian grayling is part of a family of fish that includes Stokell’s smelt and the New Zealand smelt, which are both still found in rivers across Aotearoa.</p>
<p>New DNA data confirmed the Australian grayling is the closest living relative of the upokororo, but only a distant cousin at best. Genetic comparisons showed the common ancestor of the two species lived more than 15 million years ago. </p>
<p>An ancient origin for the upokororo agrees well with the discovery of <a href="https://bioone.org/journals/acta-palaeontologica-polonica/volume-57/issue-2/app.2010.0127/Fish-Remains-Mostly-Otoliths-from-the-Non-Marine-Early-Miocene/10.4202/app.2010.0127.full">fossil grayling ear bones</a> in lake sediments from Saint Bathans in Central Otago.</p>
<figure class="align-center ">
<img alt="Palaeontologists sieving for fossils in the Manuherikia River, near Saint Bathans." src="https://images.theconversation.com/files/478844/original/file-20220811-22635-5piny7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/478844/original/file-20220811-22635-5piny7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=291&fit=crop&dpr=1 600w, https://images.theconversation.com/files/478844/original/file-20220811-22635-5piny7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=291&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/478844/original/file-20220811-22635-5piny7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=291&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/478844/original/file-20220811-22635-5piny7.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=366&fit=crop&dpr=1 754w, https://images.theconversation.com/files/478844/original/file-20220811-22635-5piny7.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=366&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/478844/original/file-20220811-22635-5piny7.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=366&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Palaeontologists sieving for fossils in the Manuherikia River, near Saint Bathans. Fossils from this location are between 16 and 19 million years old.</span>
<span class="attribution"><span class="source">Nicrawlence/Wikipedia</span>, <a class="license" href="http://creativecommons.org/licenses/by-nd/4.0/">CC BY-ND</a></span>
</figcaption>
</figure>
<p>Genetic and fossil data together suggest the ancestors of the upokororo arrived in Aotearoa following the birth of the Alpine Fault. Before that time, present-day Aotearoa was mostly beneath the ocean, during the height of the Oligocene “<a href="https://www.tandfonline.com/doi/full/10.1080/00288306.2014.904387">drowning</a>” 27 to 22 million years ago. </p>
<p>While baby upokororo could live in salt water, adults needed brackish or fresh water. The emergence of Aotearoa from beneath the waves would have created new habitats for the upokororo.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/i-will-miss-them-if-they-are-gone-stingrays-are-underrated-sharks-we-dont-know-enough-about-186214">'I will miss them if they are gone': stingrays are underrated sharks we don't know enough about</a>
</strong>
</em>
</p>
<hr>
<h2>Back from the brink?</h2>
<p>Some scientists have previously put forward a controversial idea. Could the Australian grayling be released into rivers in New Zealand to fill the ecological gap left by the extinction of the upokororo? </p>
<p>That probably wouldn’t be a good plan. Millions of years of independent evolution mean the niches filled by the Australian grayling and upokororo were likely very different.</p>
<p>If we can’t replace the upokororo, is it possible that they’re still out there somewhere in a remote waterway, waiting to be re-discovered? It wouldn’t be unprecedented. Takahē were thought to be extinct before a small population was <a href="https://www.nzgeo.com/stories/takahe-the-bird-that-came-back-from-the-dead/">re-discovered in the Murchison Mountains in 1948</a>. </p>
<figure class="align-center ">
<img alt="An image of a river, overlain with fish." src="https://images.theconversation.com/files/478720/original/file-20220811-4172-eoa5ws.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/478720/original/file-20220811-4172-eoa5ws.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=397&fit=crop&dpr=1 600w, https://images.theconversation.com/files/478720/original/file-20220811-4172-eoa5ws.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=397&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/478720/original/file-20220811-4172-eoa5ws.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=397&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/478720/original/file-20220811-4172-eoa5ws.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=499&fit=crop&dpr=1 754w, https://images.theconversation.com/files/478720/original/file-20220811-4172-eoa5ws.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=499&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/478720/original/file-20220811-4172-eoa5ws.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=499&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Could the New Zealand grayling be hiding out in remote waterways, such as the West Coast’s Buller River?</span>
<span class="attribution"><span class="source">Peter James Quinn</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Genetic data provide a new tool in the search for survivors. Environmental DNA in water samples from remote catchments can now be compared routinely to known DNA from the upokororo. Perhaps one day this will lead to a positive match that indicates the location of survivors. </p>
<p>Fish populations are in sharp decline globally. Lessons learned from past extinctions, like that of the upokororo, can help us preserve fish species for future generations. Hopefully we can heed the lessons from the past.</p><img src="https://counter.theconversation.com/content/187928/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Kieren Mitchell receives funding from the Royal Society of New Zealand Marsden Fund. </span></em></p><p class="fine-print"><em><span>Nic Rawlence receives funding from the Royal Society of New Zealand Marsden Fund. </span></em></p><p class="fine-print"><em><span>Lachie Scarsbrook 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>Historical accounts show the upokororo was once common in rivers across the country. It’s now officially extinct, but is there a chance survivors could still be found in remote waterways?Lachie Scarsbrook, DPhil Student, University of OxfordKieren Mitchell, Postdoctoral Fellow, Department of Zoology, University of OtagoNic Rawlence, Senior Lecturer in Ancient DNA, University of OtagoLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1436292020-08-06T14:58:03Z2020-08-06T14:58:03ZCulverts – the major threat to fish you’ve probably never heard of<figure><img src="https://images.theconversation.com/files/351530/original/file-20200806-18-6fzhpc.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3199%2C2131&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/culvert-spilling-water-splashing-out-grass-1398511157">Valley Journal/Shutterstock</a></span></figcaption></figure><p>You probably cross rivers every day without realising it. Beneath the concrete underfoot are culverts – tunnels installed under roads and railways that allow rivers to pass from one side to the other. Like bridges, culverts allow people to cross rivers, but unlike bridges, culverts often don’t allow the fishes living in those rivers to cross roads.</p>
<p>Why worry about fishes crossing roads? A <a href="https://www.worldfishmigrationfoundation.com/living-planet-index-2020">recent study</a> found that, on average, the abundance of 247 migratory fish species has fallen by 76% worldwide since 1970. The hundreds of thousands <a href="https://www.theguardian.com/environment/2019/may/08/only-a-third-of-worlds-great-rivers-remain-free-flowing-analysis-finds">of dams</a> that fragment rivers around the world are a major cause of these declines. Removing these dams, the report urged, could restore the pathways that migratory fishes take and help their populations rebound.</p>
<p>But dams are just the tip of the iceberg. Culverts are smaller, and far more ubiquitous and concealed. While scientists can track the locations of dams built around the world with satellites, culverts are hidden under roads, making it difficult to map them. Throughout Europe, culverts can be found under houses, shops and entire villages.</p>
<figure class="align-center ">
<img alt="Culverts, big and small, built below roads allow rivers to pass through beneath it." src="https://images.theconversation.com/files/350575/original/file-20200731-23-1xsg6am.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/350575/original/file-20200731-23-1xsg6am.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=441&fit=crop&dpr=1 600w, https://images.theconversation.com/files/350575/original/file-20200731-23-1xsg6am.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=441&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/350575/original/file-20200731-23-1xsg6am.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=441&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/350575/original/file-20200731-23-1xsg6am.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=554&fit=crop&dpr=1 754w, https://images.theconversation.com/files/350575/original/file-20200731-23-1xsg6am.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=554&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/350575/original/file-20200731-23-1xsg6am.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=554&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">An exposed road culvert on a stream in Chequamegon-Nicolet National Forest, US.</span>
<span class="attribution"><span class="source">Dale Higgins</span>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Culverts limit the movements of migratory fish like the <a href="https://www.wwt.org.uk/news/2019/06/14/why-the-once-common-european-eel-is-now-critically-endangered-and-what-can-be-done-about-it/17073">critically endangered European eel</a>, disrupting their access to food and spawning areas. When fish are blocked from making these essential journeys, entire <a href="https://theconversation.com/habitat-loss-doesnt-just-affect-species-it-impacts-networks-of-ecological-relationships-117687">freshwater ecosystems suffer</a>. Predators go hungry and <a href="https://www.bbc.com/future/article/20140218-salmon-fertilising-the-forests#:%7E:text=The%20bears%20who%20feast%20on,trees%20comes%20from%20the%20salmon.">flows of nutrients</a> between lands, rivers and seas are severed.</p>
<h2>Culverts cover continents</h2>
<p>In the Great Lakes of North America, <a href="https://www.fondriest.com/news/study-maps-great-lakes-basin-stream-barriers-road-crossings-worse-than-dams.htm">we estimate</a> that there are at least 250,000 road culverts installed on rivers. That’s 35 times more than the number of dams in the region.</p>
<p>Culverts are also <a href="https://theconversation.com/amazonian-dirt-roads-are-choking-brazils-tropical-streams-89226">common across</a> the Brazilian Amazon. Where deforestation increases and new farmland is created, culvert construction increases too. Throughout Amazonian streams, makeshift river crossings and poorly installed culverts <a href="https://link.springer.com/article/10.1007/s10980-016-0358-x">prevent fishes</a> from foraging and spawning. One small tributary of the Amazon is estimated to have 10,000 of these crossings. </p>
<p>In Scotland, a <a href="https://amber.international/stream-fragmentation-in-great-britain/">recent study</a> found that there are, on average, 12 kilometres between adjacent dams and weirs on any given river. Yet <a href="https://firelaboratory.uk/about/">our research team</a> found nearly 1,500 culverts on the River Clyde and its tributaries – that’s roughly 29 times more frequent than dams and weirs, translating to one culvert for every one and a half kilometre of river. You can see this on the map below. Great Britain has some of the <a href="https://science.sciencemag.org/content/354/6318/1423">highest road densities</a> on Earth, and so the true scale of river fragmentation by roads and culverts could be much higher.</p>
<p><strong>Culverts, dams and weirs on River Clyde</strong></p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/350576/original/file-20200731-23-1omw91z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A map showing how road culverts, dams and weirs intersect the River Clyde and its tributaries." src="https://images.theconversation.com/files/350576/original/file-20200731-23-1omw91z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/350576/original/file-20200731-23-1omw91z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=598&fit=crop&dpr=1 600w, https://images.theconversation.com/files/350576/original/file-20200731-23-1omw91z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=598&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/350576/original/file-20200731-23-1omw91z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=598&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/350576/original/file-20200731-23-1omw91z.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=752&fit=crop&dpr=1 754w, https://images.theconversation.com/files/350576/original/file-20200731-23-1omw91z.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=752&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/350576/original/file-20200731-23-1omw91z.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=752&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://firelaboratory.uk/">FIRE Lab</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Ensuring rivers and species can remain connected <a href="https://thefisheriesblog.com/2015/11/30/why-didnt-the-fish-cross-under-the-road/">hasn’t been a priority</a> in the design and installation of culverts to date. Hydraulic culverts like the one in the lead image are among the most prevalent designs used worldwide. Their design constricts river channels and speeds up water flow, with the aim of allowing as much water as possible to pass through during floods. </p>
<p>But this design can result in a culvert becoming “perched”, forming a mini waterfall on the downstream side of the structure. Perched culverts can prevent fishes from swimming upstream, cutting short their migration and stopping spawning.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/how-bird-life-may-be-affected-by-roads-and-what-to-do-about-it-142039">How bird life may be affected by roads – and what to do about it</a>
</strong>
</em>
</p>
<hr>
<h2>Helping fishes across roads</h2>
<p>Bridges are better than culverts for allowing fishes to cross under roads or railways. Yet not all culverts are <a href="https://wdfw.wa.gov/sites/default/files/publications/01501/wdfw01501.pdf">bad for nature</a>. Culverts designed with rivers in mind are wider and offer more natural gradients, helping water and animals to move more freely. Replacing hydraulic culverts with ecological designs, per the diagram below, can not only restore fish migrations. It can also reduce the risk of flooding, and lower <a href="https://extension.unh.edu/resources/files/Resource006641_Rep9682.pdf">repair and replacement costs</a>. </p>
<figure class="align-center ">
<img alt="A diagram comparing a hydraulic culvert with an ecological design that allows fish to move freely upstream." src="https://images.theconversation.com/files/350577/original/file-20200731-15-1fqxh10.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/350577/original/file-20200731-15-1fqxh10.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=557&fit=crop&dpr=1 600w, https://images.theconversation.com/files/350577/original/file-20200731-15-1fqxh10.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=557&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/350577/original/file-20200731-15-1fqxh10.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=557&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/350577/original/file-20200731-15-1fqxh10.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=700&fit=crop&dpr=1 754w, https://images.theconversation.com/files/350577/original/file-20200731-15-1fqxh10.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=700&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/350577/original/file-20200731-15-1fqxh10.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=700&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption"></span>
<span class="attribution"><a class="source" href="https://www.tandfonline.com/doi/full/10.1080/03632415.2016.1246875">Fisheries/O'Shaughnessy et al. (2016)</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Governments must establish laws that ensure anything built in rivers allows water and species to move as freely as possible. Indigenous nations in the US <a href="https://www.wsdot.wa.gov/Projects/FishPassage/CourtInjunction.htm">compelled</a> lawmakers in Washington state to repair or replace any culverts that failed this test. As a result, responsible agencies are <a href="https://wdfw.wa.gov/species-habitats/habitat-recovery/fish-passage/rule-making">establishing new rules</a> to ensure anything built in state waters does not negatively affect habitats. </p>
<p>Structures like culverts must be adaptable to keep species moving, even as climate change causes river flows to change. But <a href="https://www.nature.com/articles/495308a">when planners decide</a> to build new roads in most other places worldwide, the consequences for rivers and fishes are rarely considered.</p>
<p>As road networks expand to connect more of the world, we urge governments to better regulate the design of culverts that intersect these routes. Only by ensuring that fishes can cross roads can we hope to reverse the steep declines that our construction habits have wrought.</p><img src="https://counter.theconversation.com/content/143629/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephanie Januchowski-Hartley receives funding from Welsh European Funding Office and European Regional Development Fund under project number 80761-SU-140 (West). </span></em></p><p class="fine-print"><em><span>Cecilia Gontijo Leal receives funding from São Paulo Research Foundation (FAPESP) under project number 2017/25383-0.</span></em></p><p class="fine-print"><em><span>Sayali Pawar receives funding from Welsh European Funding Office and European Regional Development Fund under project number 80761-SU-140 (West).</span></em></p>Fish need to cross roads too. But the tunnels built to channel rivers under roads and railways can block their migrations.Stephanie Januchowski-Hartley, Sêr Cymru Research Fellow in Environmental Sciences, Swansea UniversityCecilia Gontijo Leal, Postdoctoral Researcher in Applied Ecology, Universidade de São Paulo (USP)Sayali Pawar, Research Fellow in GIS and Environmental Change, Swansea UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1218982019-08-15T10:23:37Z2019-08-15T10:23:37ZFinding Dory did not increase demand for pet fish despite viral media stories<figure><img src="https://images.theconversation.com/files/288028/original/file-20190814-136180-6msesd.png?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Martin Pelanek / shutterstock; Disney / Pixar</span></span></figcaption></figure><p>If a piece of information is repeated often enough, it will eventually be believed, even if there is no evidence for it. One example of this features the friendly clownfish Nemo and his side-kick Dory, a blue tang fish, who you may know from the animated blockbusters Finding Nemo and Finding Dory.</p>
<p>Everyone loves Nemo. But to some, his rise to global stardom in 2003 had a darker side, as news outlets around the world reported that the popularity of the movie was leading an increasing number of people to buy clownfish as pets. These articles claimed that this increase in demand was a threat to wild populations. While there was little to no evidence to support this story, with so much repetition, <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/faf.12202">the so-called Nemo Effect</a> became conventional wisdom.</p>
<p>So it wasn’t surprising that before its sequel, Finding Dory, was released in 2016, a chorus of voices, including Ellen DeGeneres who voices Dory in the movie, once again <a href="https://www.yahoo.com/entertainment/ellen-degeneres-finding-dory-plot-nemo-fish-as-127100666812.html">raised the alarm</a>. The calls were, however, dwarfed by the <a href="https://www.the-numbers.com/market/">more than 50m spectators</a> who watched the movie in the US alone. Could there be a Dory Effect? </p>
<p>Dory is a blue tang, a species found across much of the Indian and Pacific Oceans. Despite its popularity as an aquarium fish, it’s currently <a href="https://www.iucnredlist.org/species/177972/1507676">not considered to be threatened</a>. Still, increased sales could constitute a threat to wild populations since, in contrast with clownfish which are often <a href="https://www.orafarm.com/products/fish/clownfish/">bred specially for the trade</a>, blue tangs cannot be reared in captivity and there are no alternatives to wild-caught fish.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/288025/original/file-20190814-136195-fo25ep.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/288025/original/file-20190814-136195-fo25ep.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/288025/original/file-20190814-136195-fo25ep.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288025/original/file-20190814-136195-fo25ep.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288025/original/file-20190814-136195-fo25ep.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288025/original/file-20190814-136195-fo25ep.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288025/original/file-20190814-136195-fo25ep.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288025/original/file-20190814-136195-fo25ep.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"></a>
<figcaption>
<span class="caption">Nemo and her eggs: clownfish are relatively easy to breed in captivity.</span>
<span class="attribution"><span class="source">Jenny Lord / shutterstock</span></span>
</figcaption>
</figure>
<p>To find out if there had been a Dory Effect, my co-authors and I compared how sales of blue tang fish changed over time, as compared to other species of the same family that are also traded as pets. Our results are now <a href="https://link.springer.com/article/10.1007/s13280-019-01233-7">published in the journal Ambio</a>.</p>
<p>We found no link between the release of the movie and the number of fish imported into the US, where many of the viewers were located. This is to some extent not surprising as blue tang are large and hard to keep, and so not particularly suitable for first-time fish enthusiasts. </p>
<p>So what other things could movie goers do as a result of watching Finding Dory? There is some evidence that animated blockbusters can influence people to visit these and other ornamental fish at an aquarium. We looked at visitor numbers over time at 20 US aquariums to see if there had been any changes associated with the release of the movie. Again, we did not find any effect.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/288032/original/file-20190814-136230-dw1k1y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/288032/original/file-20190814-136230-dw1k1y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/288032/original/file-20190814-136230-dw1k1y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/288032/original/file-20190814-136230-dw1k1y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/288032/original/file-20190814-136230-dw1k1y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/288032/original/file-20190814-136230-dw1k1y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/288032/original/file-20190814-136230-dw1k1y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/288032/original/file-20190814-136230-dw1k1y.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">Dorys are bigger than Nemos, and harder to keep as pets.</span>
<span class="attribution"><span class="source">szmuli / shutterstock</span></span>
</figcaption>
</figure>
<p>We then turned to an indicator that related to a less expensive and time-consuming behaviour, the act of searching online, in particular, searching on Google for different ornamental fish species. We again compared the blue tang fish with other ornamental fish of the same family. This time, things were different. </p>
<p>We found a sharp rise in the frequency of Google searches for the scientific name of the blue tang: <em>Paracanthurus hepatus</em>. This showed that while Dory fans were not willing to invest time and money to buy pet fish or visit an aquarium, they were indeed willing to search online for information about the species, an act involving little investment in money or time.</p>
<p>Our results show that contrary to what was previously widely reported, the movie Finding Dory was not responsible for an increase in demand for the blue tang fish, but it did encourage people to seek more information about the species. It seems blockbusters can play an important role in putting a more diverse group of species in the public’s mind. This is key for conservation as we know that the least familiar species are less often perceived to be <a href="https://zslpublications.onlinelibrary.wiley.com/doi/10.1111/acv.12477">worthy of conservation support</a>.</p>
<p>Finally, these findings also highlight how we need better links between the press and the scientific community, to ensure that stories based on anecdotal evidence such as this do not gain unwarranted momentum and end up shaping public opinion and even public policy. </p>
<p>There are several similar stories to this one out there. For example, there are reports of the Harry Potter movies driving <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0182368">demand for pet owls</a> or the movie Zootopia leading to a spike in the demand for <a href="https://blog.nationalgeographic.org/2016/05/23/is-zootopia-creating-demand-for-pet-fennec-foxes-in-china-spoiler-probably-not/">pet Fennec foxes</a>, despite no evidence to support them.</p>
<p>Scientists and journalists need to find better ways of working together to ensure more factual coverage. In the era where experts are sometimes seen as irrelevant and fake news plagues our media streams, this improved relationship will be vital to demonstrate the value of both groups to society.</p><img src="https://counter.theconversation.com/content/121898/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Diogo Veríssimo is affiliated with the Institute for Conservation and Research, San Diego Zoo Global. </span></em></p>The ‘Nemo effect’ wasn’t real, and new research also found no evidence Dory led to increased imports of wild blue tang fish.Diogo Veríssimo, Oxford Martin Fellow, University of OxfordLicensed as Creative Commons – attribution, no derivatives.