Susan,
Thanks for your favourable comment.
Could claim to be clever about the chop shop but I think that would be just too clever.

Nick,
By the way, ABARES' comprehensive assessment Fishery Status Reports 2012 is due very shortly and will be available online. This is a very well done and covers all commonwealth fisheries as well as those fisheries under regional agreements like southern bluefin tuna and the Western and Central Pacific Tuna Fishery.
It's plain talking about 'overfishing' and 'overfished' stocks and usually makes some pointed remarks about management and bycatch issues.

Ib,
Yes, you put your finger on the trawling problem. While trawling is being gradually wound back it still causes many problems for wildlife and destroys the benthic ecosystem.

Luc,
I think more and more people will come to that decision, especially for wild fish. But then some aquaculture can be very cruel, so differentiating there is important.

Jane,
Good point. I am referring to the publiication dates. The 2012 version will be to 2011.

Fred,
You ask some pointed questions.
The difficulty of making assessments of fish or fisheries on ecological or bycatch criteria is that it always comes down to a subjective or, at best, a group subjective basis. When assessing stocks, one has a benchmark: below such and such a biomass the stock is overfished. However, what is the level of bycatch that is tolerable. One seal? Some would say even one seal is too many.

Fred.
A very apt suggestion.
I think, as an economist, that looking at the opportunity costs of overfishing would be very relealing. Tom Kompass et al have done some great work looking at how much more money could be made by fishing less. A wider study would reveal the millions if not by now billions of dollars worth of ongoing sustainable production lost over the years because of overfishing and lack of recovery of stocks such as orange roughy and toothfish, to name just two.

The Foreword to the report, by Ian Curnow Chair, Australian Fisheries Management Forum and The Hon. Harry Woods Chair of the Fisheries Research and Development Corporation Board of Directors states the following:

The Status of key Australian fish stocks reports do not aim to be an eco-labelling guide, but rather a scientifically robust, simple tool to inform fishers, seafood consumers, managers, policy makers and the broader community, and allow ready comparisons between the status of the key wild-caught fish stocks around Australia.

My article comments on the claim of the report to be useful as a tool to inform seafood consumers.

John,
We can't ban the trade in fish.
But, as you say the escalating price of wild caught Australian fish has meant that it has become a luxury rather than a staple.
Even more worrying is what escalating exports of fish from south east Asia is doing to the environment. I have personally witnessed the massive destruction of the coast that shrimp farming for export has caused in Thailand; it is also bad in Indonesia, the Philippines and China.

Dear Caleb,
I am also a scientist and have worked in fisheries management at the cutting edge, including with the southern rock lobster.
My claim on southern rock lobster is that it is alarming that the stock is down to a third of its original biomass, as reflected in egg production. This is of concern to consumers. The stock should be built up and not be subject to catch quotas that simply sustain the stock at a fraction of what it was. See the steep decline in catches over the last 4 years in Figure 2a of the report. I suggest that the public is concerned about such economic losses due to overfishing.
In ABARES’ latest assessment in the Fisheries Status Report published in 2011, the status and catches of the three fish you claim are no longer available for consumers, for 2010-2011, were as follows: jackass morwong (subject to overfishing) 400 tonnes, eastern gemfish (overfished and subject to overfishing) 92 tonnes, and blue warehou (overfished and subject to overfishing) 145 tonnes.

Dear Colin,
Harvesting deletes biomass so I'm afraid catch quotas >0 will always sustain the stock at a fraction of what it was. The issue is what fraction is of concern. You can assert that stock depleted to 30% of the unfished state is of concern to consumers but the challenge for a forum like this is explain why.

In the case of the SRL fishery you discuss, benchmarks were followed, based on science, that provide high confidence that recruitment will not be affected by fishing.

I'm concerned that you have worked at the cutting edge in fisheries management but perceive reduced catches in a TAC controlled fishery as alarming. Catch is reduced in ITQ fisheries to prevent overfishing so I would view the smaller harvest as indication of effective management. In this case the catch has also been reduced in some parts of the stock because of a change in strategy to target maximum economic yield. As you'd appreciate, this generally requires a reduction in catch and higher biomass targets. You should also understand that catch and egg production are not necessarily closely linked in fisheries such as this because so much of the egg production originates from females in the sub-legal sized stock (because the population is protected by size limits in addition to the catch limit).

In terms of this issue of the three fish species available / not available to consumers - you are obviously correct that some small catch is landed but the point is that this landed catch is small and taken as incidental catch rather than through targeted operations. The species were not included in the report because consumers have slim chance of encountering one of these species with such low incidental catch. Their decision to purchase or avoid these species does not send a market signal because targeting has ceased and bycatch limits have been established as part of recovery plans.

Dear Caleb, In response to your second comment, below, I provide the following excerpts from the latest state assessments of their Southern Rock Lobster fisheries. These suggest that catches have been set too high for years.
SA Northern Zone Southern Rock Lobster Fishery:
“Estimates …indicate a general decline in lobster biomass over the last three decades.”
SA Southern Zone SRL Fishery:
“…from 2003 to 2009 biomass decreased by 61%.”
Victoria SRL Fishery:
“Due to concerns regarding low catch rates in the WZ, industry requested that commercial fishing in this zone be suspended over June/July 2007, and again in June/July 2008.”
Tas SRL Fishery:
Decline in productivity…has resulted in a decline of the legal-sized stock, which in turn has led to a need for TACC reductions. The prolonged low recruitment to the fishery is exceptional and unlike any downturn seen previously over the period of four decades from 1970 to 2010.

In response to your comments on the SE Trawl, jackass morwong is a targeted species and the landing is not insignificant at 400 tonnes, which makes it the sixth largest landing in a fishery of 30 stocks. I don’t’ disagree that blue warehou and gemfish are bycatch. The point is that the Commonwealth’s Trawl Fishery is a multispecies fishery and must be managed as such.

Dear Colin,
You've made a basic errors in interpreting population dynamics here. You've assumed there's a direct relationship between recruitment and stock in the southern rock lobster fishery, and that any decline in exploitable biomass equates to overfishing. In fact there's been a significant negative correlation between egg production and recruitment over the last couple of decades, which is spurious but it does emphasise that you need to be careful with your conclusions.

Each of the reports you cite were produced by independent scientists with extensive experience in population dynamics. They reviewed a range of data sources in assessing these SRL fisheries and none concluded the stock was overfished.

Yes, recruitment varies in this species but this is expected given the larvae spend over 18 months in ocean currents beyond the continental shelf. Periods of high and low recruitment are normal as floods and droughts are on the land. Low recruitment doesn't imply overfishing but it does increase risk of overfishing if management is not responsive.

In each State you cite examples of management reducing catch in response to low recruitment. You cite one of my reports where I noted that a period of low recruitment from 2006 to 2010 was exceptional and concluded that catch should be reduced. The state government responded, catch was reduced, biomass is recovering and egg production was maintained above benchmarks for recruitment overfishing, thus ensuring fish for the future.

If your point on the Commonwealth’s Trawl Fishery is now that it's a multispecies fishery and must be managed as such - then you're in luck. Both are true.

Dear Caleb,
I take your point about the lack of correlation between egg production and recruitment. And no doubt the Tasmanian SRL is in a better shape than those in other states. Even so, you say in your assessment of the fishery:
“The capacity for the Tasmanian southern rock lobster fishery to support the annual
harvest is a function of both growth of the legal sized stock and also recruitment
of new lobsters into the stock. …Low recruitment has led to erosion of the
legal sized stock and thus reduced productivity through growth.”
In Tasmania the overfishing of large predatory southern rock lobsters has been a factor in leading to an increase in sea urchin populations. The long-spined sea urchin has overgrazed productive Tasmanian kelp beds leaving a barren environment. (Ling, S., Johnson, C., Frusher, S. and Ridgway, K., 2009. Overfishing reduces resilience of kelp beds to climate-driven catastrophic phase shift, Proceedings of the National Academy of Sciences, Early Edition, at: www.pnas.org/cgi/doi/10.1073/pnas.090729106.) And the report State of Key Australian Fish Stocks Reports 2012 says that the southern rock lobster biological stock is being rebuilt off eastern Tasmania. The stock has been overfished.

That caution is required is illustrated by the state of the important South Australian Southern Zone Rock Lobster Fishery. Despite explicit regulations, its status has declined considerably in recent seasons (Linnane et al., 2010. Evidence of large scale spatial declines in recruitment patterns of southern rocklobster, Jasus edwardsii, across south-eastern Australia, Fisheries Research, 105:163-171). Catch per unit effort (CPUE) has decreased from an historical high of 2.1 kg/potlift in 2002/2003 to just 0.6 kg/potlift in 2009/2010 the lowest on record. This decrease reflects declines in estimated legal size biomass from∼4800 tonnes to∼1800 tonnes and a doubling of exploitation rates from∼0.35 to ∼0.7 over the same period (Linnane et al., ibid.), and has resulted in substantial reductions to the TACC from 1900 tonnes in 2002/2003 to 1250 tonnes for the start of the 2010/2011 season (Punt, et al 2012. Evaluating empirical decision rules for southern rock lobster fisheries: a South Australian example, Fisheries Research, 115–116: 60–71.)

A problem for the State of Key Australian Fish Stocks Reports 2012 is that it lumps together the several southern rock lobster fisheries and assesses the whole as sustainable instead of differentiating between them. The science is clear: there has been a serious decline in stock status in SA’s Rock Lobster Fisheries and the Western Victorian stock is overfished. The cuts in overall quota, of 27% over three years, does not guarantee that there will be recovery in individual fisheries. Increasing climate change impacts add considerably to the uncertainty of the effectiveness of quotas reductions in leading to stock recovery.

The point about a multi-species fishery such as the SE trawl is that it is misleading to claim in the State of Key Australian Fish Stocks Reports 2012 that catches of selected species are sustainably fished while other fish, inevitably caught at the same time, are subject to overfishing and overfished.

Dear Colin,
This is becoming circular so I'm not sure there's much point in continuing because again you've simply cited information unrelated to the assessment of recruitment overfishing.

There is no debate that recruitment varies through time and this has resulted in both historic highs and lows (since 1970) of legal sized biomass in many areas during the 2000's. There is no question that catches needed to be reduced in recent years due to periods of low recruitment. This was motivated by the desire to maintain catch rates at higher levels for economic objectives. High catch rates reduce cost of fishing for the same catch. Economic benefits from the fishery are important but sustainability needs to come first. At no point was reproductive capacity (egg production) at risk and it did not fall below benchmarks for overfishing.

Your long series of quotes deal with changes in legal sized biomass not reproductive capacity. To illustrate why this isn't necessarily relevant: i) there are regions of the stock where females do not contribute to the legal sized biomass at all and it would be theoretically possible to fully deplete the legal stock yet have natural levels of egg production; ii) a reduction in the size limit must increase legal sized biomass but would likely reduce egg production; and iii) an extension of the female closure would increase egg production but would likely have no effect of legal-sized biomass.

You've argued that the spatial scale of the assessment isn't appropriate because there is spatial variation in the density of legal sized biomass. Spatial scale is important in fisheries and this report was a significant step forward because it assessed fisheries over biologically meaningful areas rather than being bounded by states. The SRL is a single stock across the range due to the extended larval dispersal.

Dear Caleb,
The references are cited are key, directly related to the status of southern rock lobster stocks and used by state reports or by the report Status of Key Australian Fish Stocks Reports 2012. I rest my case that the science is clear that there is serious concern for the future of stocks, and that the “sustainable” tag given the southern rock lobster in Status of Key Australian Fish Stocks Reports 2012 is overoptimistic.The science is clear, but will management be able to turn things around?
From consumers’ point of view there is a need more information, including spatial differentiation of southern rock lobster stocks, not less.
Maximum economic yield in fisheries is always at a lower exploitation level than maximum sustainable yield. More emphasis on this as a criterion in management would increase profits and as well as reducing the risk of crashes.

Dear Colin,
Yes, the references are clear but it's not clear how you draw such different conclusions to the authors of each report. None of these reports concluded that the fishery was overfished as you do and all were based on a formal process of evaluation against fisheries indicators and reference points. If you think the data are wrong or that performance indicators used in fisheries science to define recruitment overfishing are wrong, then you should pursue that.

The National Report assessed SRL as sustainable based on current stock levels, not on projections of outcomes of management. So speculating on whether further stock increase will occur under current management isn't relevant. The stock is already above benchmarks.

Maximum economic yield does involve higher density and lower exploitation rates (at societal appropriate discount rates at least) and are a reasonable objective for fisheries. This is an important issue, one I'm very interested in (as an economist), but again irrelevant to whether the fish stock is recruitment overfished.

I'm not going to claim to speak on behalf of consumers, as you feel able to, but assessing stocks at biological rather than jurisdictional scale is a goal of modern fishery science.

Dear Caleb,
It comes down to the definition of “sustainable”.
One can sustain a fishery at any level.
The facts are: stock rebuilding is starting to occur in SA NZ, stock is needing to rebuild in SA SZ, stock is declining in Tas, and the CPU is the lowest in history and the stock rate of rebuilding very low in Vic Western zone.
I would say that once rebuilding is confirmed over a period for each of these fisheries then the fishery could be said to be truly “sustainable”.

Dear Caleb,
Your statement that the National Report assessment for Southern Rock Lobster as sustainable is not based on projections of outcomes of management is in error. Control of fishing pressure is a management activity.
The definition of sustainability in the Status of Key Australian Fish Stocks Reports 2012 is as follows:
“Sustainable stock—indicates that biomass (or biomass proxy) is at a level sufficient to ensure that, on average, future levels of recruitment are adequate (i.e. not recruitment overfished) and that fishing pressure is adequately controlled to avoid the stock becoming recruitment overfished.”
Individual fishery assessments show that stocks are now greatly reduced due to past overfishing. And the assessments throw up very serious doubts indeed about whether the criterion “fishing pressure is adequately controlled to avoid the stock becoming recruitment overfished” can be met. (This obviously refers to catch levels set by fisheries managers.)
The source of these serious doubts are the conclusions from the latest scientific assessments of the three main Southern Rock Lobster fisheries.
You yourself say, with respect to the Tasmanian Rock Lobster Fishery:
“The continuing increases in effort, reduction of catch rates and increasing level of uncaught quota continue to raise serious concerns for the fishery. Without more normal levels of recruitment and a TACC which constrains the catch, the biomass and subsequent catch rates will continue to decline under the current total catch.” (Hartmann, K., Gardner, C. and Hobday, D. 2012, Fishery Assessment Report, Tasmanian Rock Lobster Fishery 2010/11, IMAS, Hobart,: 59.)
In the South Australian Southern Zone Rock lobster fishery the science says: Reduced biomass by over 60% between 2000 and 2009; egg production in 2009 <10% of virgin levels, and catch per unit of effort falling two thirds from 2003 to 2009. Recruitment is likely to reduce for 2013 to 2016. (Linnane, A., McGarvey, R., Feenstra, J. and Hawthorne, P. 2012. Southern Zone Rock Lobster (Jasus edwardsii) Fishery 2010/11, Fishery assessment report for PIRSA Fisheries and Aquaculture, SARDI, Henley Beach, SA: 1-2.)
In the Victorian Rock Lobster Fishery Western Zone: “From 2003 to 2009 nominal catch per unit effort decreased by 47% the lowest level in history of the fishery. Annual catches have declined from 525 tonnes in 2000 to 235 in 2008 reflecting catches in TAC. From 2003 to 2009 model projections indicate a TACC could, given stable long term average recruitment, rebuild the available biomass to the target reference point by 2020.” (Linnane, A., Chick, R.C., Walker T., Trinnie, F. and Reilly, D. 2012. Victorian Rock lobster and Giant Crab Fisheries status report to Fisheries Victoria, SARDI, Henley beach, SA: viii.)
I provide the references so that interested readers can follow up for themselves.

Dear Colin,
You’ve misunderstood. Fisheries scientists assess the status of fish stocks against a series of pre-determined performance indicators and these can be based on both hindcast and projected measures. Both are used in fisheries assessments in Australia but with the specific case of the National Status Report, only hindcast measures are used (eg estimated biomass, egg production and fishing mortality). Some jurisdictional assessments incorporate projections based around some future goal for the fishery. These typically have three components – the what, the when and the likelihood. These are more often used in relation to economic objectives, for example, to transition the stock to maximum sustainable economic yield within 5 years with a 75% probability. This approach typically requires sophisticated modelling and can only be applied in data-rich fisheries.
So there’s no mistake – projections were not used in the National Status report. This is appropriate and logical for the status report because it was intended to provide a snapshot of fish stocks in 2010, not how they may be at some time in the future. Using model projections to help make management decisions is useful in fisheries but a different process to status reporting.
Hindcast performance indicators such as estimated biomass and egg production are used in fisheries assessments to determine the status of stocks by comparing the observed levels against pre-defined benchmarks. These benchmarks can be set to meet a range of objectives and in the case of the status report, the definition as you’ve quoted is clear.
An important benefit of this formal scientific approach is to remove subjectivity from assessments. You’ve again claimed that “individual fishery assessments show that stocks are now greatly reduced due to past overfishing”. I’m still not sure how you’re claiming this but it seems to be subjective because you’ve given no benchmark on what is / isn’t overfishing. I dislike this type of subjectivity, not least because it’s identical to the subjectivity I see used in the opposite situation when people try to claim that performance is acceptable when it’s not.
I’m not sure if you’re unclear on population dynamics but you have mixed up many indicators in these references. Your quotes from Tasmania relate to an economic performance measure not sustainability. There’s no question that there’s a gap between the current economic performance of the fishery and its potential, as is true of most fisheries (and most food production industries I’d imagine). This is something that needs attention but it’s obviously possible to have fisheries that are sustainable but not economically optimised. The National Status report deals with sustainability. I recommend scrolling onto P41 of the Tas report if you’re interested in this objective for that jurisdiction.
The statement that recruitment in SA is expected to fall from 2013 to 2016 is based on observed puerulus (juvenile) settlement monitoring. Larval settlement varies from year to year so there’s a 50% probability of decline in recruitment in any one year assuming zero time trend. As you’re aware but haven’t reported, there have also been record spikes in recruitment recently so it’s not possible to determine any long term trend either up or down. Your quote on the Victorian fishery deals first with the economic loss from low abundance of legal sized biomass and then moves on to the model projection that indicates rapid stock rebuilding is expected.
This is over and out from me but I welcome your enthusiasm for reading through so much assessment reporting and invite you to call and discuss the reports in more detail if the process or conclusions aren’t clear.
Caleb

Trevor, thanks for your thoughtful comments, prompted by your first hand south-east Asian experience. Like you I was shocked. I spent time with a PhD student studying the ecology and economics of shrimp farming in Thailand's coastal zone. The coast and its mangroves were decimated by the construction of ponds (often subsequently abandoned due to disease), as were the fisheries supplying the feed for the shrimps.
However, I don't think we should risk the same thing happening here. Our coastal zone is incredibly rich. There is a need to take account of what is being lost as well as the benefits of aquaculture. If the farms are land-based they need to be well sited, and should have closed systems that recycle all water and effluents. Moreover the fish in the feed need to be sourced from sustainable fisheries. Where fish are fed in pens in inshore waters much effluent results - the conversion ration of the feed is usually poor in the case of predators such as tuna and salmon. The intensity and scale of these latter needs monitoring to prevent damage to the marine ecosystem; then there are ethical issues, as mentioned in another comment.