The science of sustainable seafood, explained

Three experts talk about MSC’s potential bluefin tuna certification

The Marine Stewardship Council (MSC) assessment process has been criticized recently by WWF: “the potential sustainability certification of the first Atlantic bluefin tuna fishery, following a questionable evaluation process that has repeatedly ignored the fragile status of the stock.”

Back in February, we reported on WWF’s initial objection to this potential certification. Then in June, joined by the Pew Charitable Trusts, WWF presented evidence to an independent legal expert to argue that the assessors were incorrect to pursue a certification of environmental sustainability.

Eastern Atlantic bluefin tuna, like most stocks of bluefin, has experienced severe overfishing, illegal, unreported and unregulated fishing (IUU), and mismanagement that spiraled populations down to levels too low to facilitate responsible commercial harvests. Since the worst levels of depletion in the 1990’s and early 2000’s, WWF, Pew, Oceana and many other environmental NGOs have built comprehensive campaigns focused on bluefin recovery efforts.

But, thanks to stricter management, conservatively low quotas, and a crackdown on IUU fishing, the Eastern Atlantic bluefin population has recovered over the last decade. The International Commission for the Conservation of Atlantic Tunas (ICCAT), the intergovernmental organization responsible for managing the stock, has shown promising declines in illegal catch and fishing mortality rate, and increases in spawning stock biomass (SSB) for the better part of a decade.

Spawning stock biomass of Atlantic bluefin tuna.
SSB (in thousand metric ton), recruitment (in million), and fishing mortality (average over ages 2 to 5, and 10+) estimates from Virtual Population Analysis base run from the 2017 stock assessment for the period between 1968 and 2015. From ICAAT 2019.

Despite ICCAT’s most recent stock assessments, WWF believed the MSC, “dismissed the best available science and therefore produced a much too positive evaluation of the fishery that does not reflect the reality at sea.” Impartiality was also cited by WWF as a major concern in the certification process.

If the certification is approved, it would only apply to the Usufuku Honten fishery, a single vessel fishery of 400 tons of quota for 2020, 1% of the 36,000 tons allotted for the entire Eastern Atlantic bluefin tuna stock this year. But given the sensitive history of this fishery and the continued management issues of other bluefin fisheries around the globe, the NGO community is worried this certification may set a dangerous precedent and confuse consumers. “We are strongly concerned that granting the MSC certification to the first Atlantic bluefin tuna fishery will send the wrong message to consumers that trust the label with the understanding that it is a proof of sustainability. Unfortunately, that is not always the case,” Di Carlo explained.

To get a clear picture of the best available science we spoke with three tuna experts that know the fishery well and have been part of the assessment teams:

Rishi Sharma | Senior Fisheries Resources Office, Marine and Inland Fisheries Division, FAO

Steve Cadrin | Professor of Fisheries and Oceanography, University of Massachusetts

Victor Restrepo | Vice President of Science, ISSF; former Assistant Executive Secretary at ICCAT; opinions expressed are his own

How is this fishery doing well, given the controversy? What are the signs that the stock is recovering?

Sharma – Managers have made a lot of good decisions in the fishery over time. Back in 2011 and 2012 they cut the quota by 60-70%. Cutting the quota from 50,000 tons to 10-11,000 tons was a pretty massive cut, and they operated on that for 3 or 4 years. When you reduce the quota to that degree you really aren’t fishing the small fish, you’re letting the stock actually reproduce. Serendipitously, the stock had good recruitment for that period as well, so the stock really benefitted and bounced back amazingly. All the indices of abundance showed an increasing trend in the last assessment which was 2017.

Cadrin – Our indices of abundance – whether it’s the fishery indices, catch rates, or the fishery independent surveys (larval surveys, etc.) – they are all indicating an upward trend in the stock size. The size and age structure are also suggesting the stock is rebuilding.

Restrepo – All the signs are that the SSB is increasing. That comes from the catch rates and any kind of modeling, and from the fact that areas where BFT had disappeared, like the feeding grounds of Norway, BFT have been coming back since 2012 or so. There are many different kinds of signs that it is rebounding.

Where does the fishery still need to improve? How is it vulnerable?

Sharma – There may still be issues with misreporting in the farming sector. There are also problems with the index of abundance data set used in the last assessment due to issues of hyper depletion and non-representativeness. The way they are fitting the models right now is giving everything equal weight and I don’t think that is appropriate right now. If you have 10 signals of abundance and you actually give everything the same weight you’ll just get an average. However, if you think something is more plausible statistically or has used a better methodology for collecting that data, then that could be weighted higher and that would probably tell you something quite different. Such considerations are not being made in the recent assessments. Ultimately, the model relies on data that is uncertain and hence, uncertainty bounds could be much larger than currently presented in the 2017 assessment. However, the overall biomass trend is still positive.

Cadrin – Sampling for years has been low and there were periods of misreported landings. Recent data are better, but when you try to go back to estimate some of the baselines, some of that information is uncertain, and so the model results are uncertain.

If anything, the model is so positive that I think it gives a lot of us caution. Everything looks good but there is this great deal of uncertainty, and really for each of the last three updated assessments, things looked so good that we were really trying to caveat the positive news coming from it in the way of uncertainties.

But going back to this recent hearing in which WWF said it’s not based on the best science – I would argue the best available science does have a very positive view of the fishery. I think we do need to be cautious, but there is also no evidence to be alarmed either.

Restrepo – Some politicians and many fishers are claiming victory, that the stock is already recovered, and we can ease restrictions. I don’t think that is the case, I think they need to keep up with those restrictions or risk losing the progress made over the last decade.

Is there any aspect of ICCAT’s assessment methodology that you would change or question?

Sharma – A length-based integrated assessment model has the ability to weight different sources of information that you’re using in your fitting procedure. The virtual population analysis (VPA) standard used by ICCAT for eastern Atlantic bluefin tuna also has that ability, but the way ICCAT ran that was they gave equal weights to all sources of information.

VPA is the standard methodology for the eastern bluefin assessment used in the past. Anything new to come into the picture must be compared to it. I will say though that this other approach (LBIA) is used extensively in ICCAT for other fisheries, so it is not completely unfamiliar. But if the choice is between a new model that has not been thoroughly vetted for this fishery which has lower projections, and the traditional model that allows for a higher TAC to be justified, the choice of policy makers between the two methods was not surprising.

Cadrin – In principle, an integrated length-based assessment would be better. For western Atlantic bluefin tuna we have both the traditional VPA and a stock synthesis model which is an integrated size-age based model. There have been continual efforts to advance that for eastern Atlantic bluefin tuna too, but it wasn’t quite ready to form the basis of management advice. I think it’s all of our expectations that with another iteration or two we can advance the eastern Atlantic bluefin tuna assessment to an integrated model.

I don’t expect that there would be much different results, however. Like I said, the same increasing indices of abundance expanding size and age structure, that’s going to be interpreted the same way whether it’s a VPA or an integrated analysis.

How big of a consideration should IUU fishing be in these assessments and certifications?

Sharma – It was a massive issue back in 1996-2006, but now I don’t think currently it is a major issue. They have fixed a lot of those problems. But I have heard some concerns about the bluefin farming sector. I think that has some unreported catch and some issues but overall the impact is marginal.

Restrepo – IUU fishing was a huge factor back when I was working on this fishery. It is possible that it is still going on, but it is much more difficult than before because of all the management control systems they have in place today. However, the farming aspects of bluefin tuna are very difficult to control. The farming in some places in the Mediterranean is only for a few months and in some other places it is for a few years, and the fish can gain a lot of weight in those months or years, so the potential of laundering catches through those kinds of operations is there. That’s something that they need to monitor very carefully – I’m not implying IUU is going on through that kind of laundering, I’m just saying there is a potential for that.

In your opinion, does the best available science support and MSC certification for this fishery?

Sharma – The VPA has a serious retrospective pattern, i.e. it tends to say there are more fish than they really are, and this has been a systematic bias in the assessment since 2011 or so. The integrated length structured assessment has had very little bias with that diagnostic so it performed better in that respect. I am also concerned that the stock has not gone through at least two generations since it was in serious trouble. Ultimately there are some significant uncertainties.

Cadrin – There is no information to suggest there is a conservation concern, that there is unsustainable or even over target fishing, that the stock is not rebuilding – nothing in that assessment to suggest the management was unsuccessful or the stock is not productive. In fact, it is just the opposite; there is a lot of evidence that the stock is productive and responding to management.

Restrepo – I haven’t gone through all of the MSC certified fisheries, but I imagine they include many that at some point were overfished in the past and have since recovered due to good management. If that is the case for eastern Atlantic bluefin tuna and they can demonstrate it meets the MSC standards then it could be certified.

I do not think it is right to penalize forever a fishery that was overfished and poorly managed in the past. In that sense I think some NGO campaigns are too negative. If they see recovery, they should recognize it and reward it somehow.

WWF said this certification would compromise ongoing recovery efforts for other bluefin tuna stocks and possibly set a bad precedent for future certifications. Too what extent do you agree with those concerns?

Sharma – That’s the million-dollar question, will there be a domino affect because now you have precedence for this vessel getting certification even though all the things were not in place perfectly. But I don’t know how much of a role the scientists should be playing in advocacy, maybe they should be saying, “hey look there’s no management procedure as yet”, a key component of the MSC certification. ICCAT gives the MSC all the information and then the MSC conducts its evaluation. The MSC is supposed to be an independent arbiter so if there is any controversy, I don’t think it should be put on the scientists in this instance, as that should have been easily discerned by the MSC experts doing the assessment.

Cadrin – High value leads to vulnerability, so there will always be the potential for a problem with bluefin tuna, but I think certification should be based on the current state of the management and the resource, and both look certifiable to me.

 As I understand it, the MSC certification is trying to incentivize best practices. That is well intentioned and somewhat effective. Industry groups that used to be critical of science and management are now valuing and demanding good science and management so that they can attain their certification.

Restrepo – I’ve been reading some of the NGO oppositions that it would be problematic because it could open up the potential for uncertified bluefin to make it into the certified market. I understand some of the concerns about uncertified bluefin potentially entering into certified markets illegally, but MSC has controls over the certified products in terms of chain of custody, so I think there are safeguards against that and I hope that doesn’t become an issue.

On the positive side, if it is certified and passes all the standards, it could show a good example that fisheries that are overfished can recover and obtain rewards later on, so I see a really positive potential there. It could show not only bluefin fisheries but other fisheries, that if they make efforts to rebuild adequately, market rewards can be attained.

Since speaking with these experts, the independent adjudicator analyzing the formal objections from the WWF and Pew has decided to uphold one of the four primary issues raised. The adjudicator has requested that the assessment body for this certification reexamine its initial methods that were used to determine how long bluefin tuna take to grow and reproduce. Control Union Pesca Ltd., the assessment body in this case, has until July 10th to respond to these objections.

Rohan Currey, chief science and standards officer at the MSC, explained. “Robust contributions from stakeholders such as WWF and [Pew] are an essential and welcome part of the independent assessment process. It’s clear from the independent adjudicator’s comments that both organizations have influenced his decision.”

Reexaminations are part of the MSC process and normally are not unusual enough to make the news. This does not mean the certification will be denied, but it does provides some additional credibility to the objections. The final decision will be even more closely monitored than before.

Jack Cheney

Jack Cheney

Jack has sourced, sold, cooked, and sustainably certified seafood over the past 9 years. In addition to his contributions to Sustainable Fisheries UW, he is working to connect chefs with US fishermen to create more value for both ends of the supply chain. He earned a Master's in Marine Affairs from the University of Washington in 2015.

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