Saving Seafood

New review shows bottom trawling is sustainable (when well-managed)

July 20, 2023 — The following is an excerpt from an article published by Sustainable Fisheries UW:

Seafood produced by bottom trawling can have a lower environmental impact than chicken or pork, according to a new review paper published yesterday. Writing in the ICES Journal of Marine Science, Hilborn et al. 2023 argues that banning bottom trawling would increase negative environmental impacts by increasing terrestrial protein production.

Hilborn et al. 2023, reviewed dozens of papers about bottom trawling impact, including stock sustainability, bycatch, ecosystem impact, and carbon footprint. Though bottom trawling is generally the most impactful kind of fishing, well-managed bottom trawl fisheries produce food with a much lower environmental impact than any terrestrial animal protein.

A review paper summarizes the current knowledge on a particular topic by combing through and presenting conclusions from recent publications. In this case, Hilborn et al. 2023 reviewed the existing literature on the environmental impacts of bottom trawling and summarized four major impacts: Sustainability of target species, impact on benthic ecosystems, bycatch and discard, carbon emissions.

The key to reducing impacts and sustaining fisheries is management. Bottom trawling can be a low-impact form of food production in places with effective management. Bottom trawling can be highly destructive in areas with little capacity for environmental management (like many developing nations in Asia).

In this post, we summarize the findings from the four major impacts, discuss what effective bottom trawling management looks like, and compare the environmental impact of bottom trawling to other forms of food production.

Read the full article at Sustainable Fisheries UW

Critique of No-Take MPA Study Published by Nature

July 8, 2022 — Last year, Sala et al. 2021 made waves in both the scientific community and mainstream press with its publication in Nature. The paper claimed that increasing MPAs to stop fishing would lead to more seafood harvest, more biodiversity, and a reduced carbon footprint—a true win-win-win for the ocean. The press release that accompanied the paper highlighted an eye-popping statistic that bottom trawling released more carbon than all airline travel; stories covering Sala et al. 2021 appeared in hundreds of press outlets worldwide.

However, the three computer models used to make each of the “win-win-win” claims have been under increased scrutiny and many scientists doubt their conclusions.

It started with the food provisioning model initially published in the Proceedings of the National Academy of Sciences (PNAS) in 2020. Inexplicable assumptions in the model and several data errors were missed by an inadequate peer review—likely due to a conflict of interest by the PNAS editor. The journal retracted it in October 2021.

You can read the whole breakdown of the retraction and the science of the food model here.

Retractions are rare in science and generally only used in cases of misconduct. Poor science is hardly ever retracted for its flaws—instead, it gets officially criticized and/or updated in the literature.

That process has now started for Sala et al. 2021, with the first official critique (and response) published today in Nature (though several critiques have been available on preprint servers).

The comment, by Ray Hilborn (founder of this site) and Michel Kaiser, points out inconsistent parameters and assumptions and criticizes the overall approach to global MPA science and advocacy.

According to Hilborn and Kaiser, the most severe flaw in Sala et al. 2021 is the inconsistent accounting of fishing effort in the author’s MPA scenarios.

In the carbon and biodiversity model, Sala et al. assumes that when an area is placed into an MPA, the fishing effort that was previously there disappears. But, in the food provisioning model, the paper assumes fishing effort moves to other areas open to fishing. This upwardly biases their claims that MPAs could simultaneously reduce carbon footprint, improve biodiversity, and increase catch:

In their calculations of biodiversity conserved and CO2 emissions reduced, the authors assume that fishing effort disappears, which would decrease total harvest at the point when the MPAs are established. Yet in the base case for the fisheries harvest section, the authors assume that fishing effort moves to areas open to fishing, keeping fishing harvests high.

MPAs certainly reduce fishing effort inside a protected area, but in the real world, fishing effort does not simply disappear—it moves outside the MPA to places where fishing is still allowed. In this scenario, the benefits to carbon emissions and biodiversity presented in Sala et al. would significantly decrease, perhaps even show a net negative response because:

Fishing effort generally goes to places with high catch rates, and if forced to fish elsewhere, more effort is required to achieve the same catch.

In their response to Hilborn and Kaiser, the original authors acknowledge that the attention-grabbing statistic in the press release that bottom trawling releases more carbon into the ocean than all airline emissions would only be true if fishing effort disappears.

Though it garnered big headlines and more attention than any other ocean science paper of the last few years, Sala et al. 2021 does a disservice to marine conservation with its analysis based on incomplete data and erroneous assumptions. Policy that follows its recommendations would potentially waste conservation effort and money on strategies that would not deliver on goals, e.g., proposing a network of MPAs where fisheries are already well managed.

Read the full story at Sustainable Fisheries UW

Shifting ocean closures best way to protect animals from accidental catch

January 18, 2022 — Accidentally trapping sharks, seabirds, marine mammals, sea turtles and other animals in fishing gear is one of the biggest barriers to making fisheries more sustainable around the world. Marine protected areas — sections of the ocean set aside to conserve biodiversity — are used, in part, to reduce the unintentional catch of such animals, among other conservation goals.

Many nations are calling for protection of 30% of the world’s oceans by 2030 from some or all types of exploitation, including fishing. Building off this proposal, a new analysis led by the University of Washington looks at how effective fishing closures are at reducing accidental catch. Researchers found that permanent marine protected areas are a relatively inefficient way to protect marine biodiversity that is accidentally caught in fisheries. Dynamic ocean management — changing the pattern of closures as accidental catch hotspots shift — is much more effective. The results were published Jan. 17 in the Proceedings of the National Academy of Sciences.

“We hope this study will add to the growing movement away from permanently closed areas to encourage more dynamic ocean management,” said senior author Ray Hilborn, a professor at the UW School of Aquatic and Fishery Sciences. “Also, by showing the relative ineffectiveness of static areas, we hope it will make conservation advocates aware that permanent closed areas are much less effective in reducing accidental catch than changes in fishing methods.”

Read the full story at UW News

URI professor part of a worldwide study on impacts of bottom trawling on health of seabeds

January 10, 2021 — A worldwide study on the impacts of bottom trawling, which accounts for a quarter of the world’s seafood harvest and can negatively affect marine ecosystems, has found that seabeds are in good health where trawl fisheries are sustainably managed.

The research published in Proceedings of the National Academy of Science (PNAS) by a team including co-author Jeremy Collie, Professor of Oceanography at the University of Rhode Island, builds on recent international collaboration in this field and is the first worldwide study of its kind. It brings together data from 24 large marine regions around the world to establish a relationship between distribution and intensity of trawling activities and the biological state of seabeds.

Read the full story at The University of Rhode Island

 

Study finds existing forage fish management is working

July 9, 2021 — Efforts to ratchet down fishing effort on species like herring and menhaden in the name of “extra precautionary management” in most cases are unlikely to bring additional benefits for stocks of predator species that eat them, according to a new study.

“Our results indicate that predator productivity was rarely influenced by the abundance of their forage fish prey,” wrote authors Christopher Free of the University of California-Santa Barbara, Olaf Jensen of the University of Wisconsin-Madison, Ray Hilborn of the University of Washington. “Only 6 predator populations (13 percent of the total) were positively influenced by increasing prey abundance and the model exhibited high power to detect prey influences when they existed,” according to their paper titled “Evaluating impacts of forage fish abundance on marine predators,” originally published in the journal Conservation Biology.

“These results suggest that additional limitation of forage fish harvest to levels well below sustainable yields would rarely result in detectable increases in marine predator populations.”

The findings were released July 6 through the Science Center for Marine Fisheries, a cooperative effort to improve sustainability of fisheries and reduce uncertainty in biomass estimates with work by university partners led with the University of Southern Mississippi Virginia Institute of Marine Science, College of William and Mary, as academic sites.

“Our work suggests that the sustainable limits that we already employ are sufficient for maintaining forage fish abundance above the thresholds that are necessary for their predators,” Free of UC Santa Barbara in a statement describing the findings. “Predators are highly mobile, they have high diet flexibility, and they can go and look for forage fish in places where they’re doing well, switch species for species that are doing well, and have often evolved to breed in places where there’s high and stable forage fish abundance.”

Read the full story at National Fisherman

Impacts of fishing forage fish on the fish that feed on forage fish

June 7, 2021 — Small pelagic fish that school in open water—think sardines or anchovies, are eaten by all kinds of predators. Seabirds, marine mammals, and bigger fish feed on these small pelagics giving them the moniker “forage fish.”

Forage fish support several fisheries, particularly “reduction fisheries,” where fish are caught and reduced into fishmeal and fish oil for livestock and aquaculture. The anchoveta fishery off the coast of South America is the largest in the world, and nearly all catch is reduced. From a food production perspective, reduction fisheries turn fish that humans don’t like to eat into other kinds of meat that humans do. That isn’t to say forage fish aren’t fished for human consumption—they are and have one of the lowest carbon footprints of any food, but the majority of catch is reduced. Eat more anchovies and sardines, people!

However, forage fish also play a foundational role in many ocean ecosystems. They buoy the diets of marine birds and mammals like whales, puffins, albatross, and other vulnerable species while also indirectly supporting valuable fisheries, e.g., salmon and tuna feed on forage fish. Their role in the food chain has led to some calls to limit forage fish fisheries to boost the populations of their higher-value predators. This makes intuitive sense, but new research out this week by Free et al. shows it’s more complicated than simply “more prey, more predators.”

In 2012, a prominent forage fish paper was published that advised a highly precautionary approach to commercial fishing of forage fish. They suggested that to be as conservative as possible, even fisheries currently considered well-managed should be reduced by 50% to enhance and maintain predator populations. It kicked off a decade of forage fish population modeling and scientific discussion. The major criticism of the 2012 paper was that the ecosystem model used in the paper assumed that commercial fishing had an outsized impact on forage fish populations and did not account for ocean conditions. However, forage fish populations are highly sensitive to environmental conditions. For example, long before humans were fishing them, the Pacific Sardine went through periods of significant population boom and bust. This environmental sensitivity complicates the understanding of fishing impact, especially because the predators eat far more forage fish than are taken via fishing. Surly overfishing is bad, but would further reducing fishing below sustainable levels benefit the broader ecosystem?

Scientists did more research. In 2017, a paper by Hilborn et al. showed little correlation between forage fish populations and their predators. The authors argued that if forage fish have natural boom and bust cycles, their predators should have the resilience to find other kinds of prey in times of bust (and indeed, most marine predators that forage on small pelagic fish have a broad diet and are highly mobile). Hilborn et al. challenged the 2012 paper’s recommendations for a highly precautionary approach to forage fish fisheries. However, it was still a relatively simple analysis—the authors used population data to show correlations (or the lack thereof) between the abundance of forage fish and changes in their predator populations. They found that just 5 of the 50 predators examined in that study showed a positive correlation to forage fish population.

The 2017 paper showed correlation but not causality—the paper published this week gets closer to causality by controlling for possible confounding factors, namely by using a predator dynamics model that accounted for forage fish boom and bust cycles. This hadn’t been in previous models. Further, the 2017 paper only looked at U.S. ecosystems; this paper included ecosystems in Europe, South Africa, and the Humboldt Current off South America, giving a more global view of forage fish ecosystem dynamics.

Read the full story at Sustainable Fisheries UW

Ray Hilborn: MPAs aren’t the answer to ocean biodiversity, sustainability efforts

June 1, 2021 — A global movement to create additional marine protected areas (MPAs) has been steadily gaining traction in recent years, with the initiative picking up milestone victories in the past few months.

In January, newly inaugurated U.S. President Joe Biden signed an executive order committing to a “30 by 30” goal, whereby the United States would designated 30 percent of its land and territorial waters to conservation by the year 2030. The move heightened the potential that MPAs will be used as a tool to tackle climate change.

Read the full story at Seafood Source

Seaspiracy’s lasting impact on sustainable seafood businesses

April 21, 2021 — With each passing day, Seaspiracy becomes increasingly irrelevant, buried in the never-ending content cue of the world’s largest streaming platform. The last month has been full of fact checks, flame wars, and funding accusations. Though it brought out the worst of everyone on social media, it brought the marine science and stakeholder community together. There is a clear consensus that the film was awful. Even Ray Hilborn and Daniel Pauly agree!

I sneer at the filmmaker’s silly “fact page,” a regurgitation of each false claim in the film listed in chronological order.  But I acknowledge—the joke’s on us. The filmmakers had no intention of presenting facts or having an honest discussion about ocean health; they sought to create a piece of horror entertainment by slandering the seafood industry. And they succeeded. For those of us in the sustainable seafood world, the cut is deep and unlikely to heal soon.

Sustainable seafood businesses didn’t deserve this. Those referring to the best available science, making public sourcing policies, exercising due diligence in their supply chains, and seeking certifications are disproportionately impacted. The film concluded that there is no such thing as sustainable seafood, making liars and cheats of those seeking it. A seafood company that makes no sustainability claims is now less likely to receive negative feedback than one that does.

Herein lies the most disgusting part of this film: it disincentivizes sustainability. Sustainable seafood products are often more expensive than unsustainable alternatives, and studies suggest consumers are not willing to pay a premium for environmentally sustainable seafood. Attempting to source seafood sustainably costs time, money, and perseverance. Like brushing your teeth, you can’t just do it once and be considered clean. A diligent seafood sustainability program requires regular re-assessments and constant attention, or else plaque will accumulate. Commitment to sustainability prohibits a fisherman from fishing in a marine protected area even though it might be full of valuable fish; it stops a chef from putting a popular item back on the menu; it requires a mid-size grocery store chain to invest valuable resources into a seafood certification program each year.

Read the full story at Sustainable Fisheries UW

Ray Hilborn on the role of industry funding

April 12, 2021 — It is true that my research program receives funding from the fishing industry. Industry funding makes up about 22% of my total funding, while I receive similar amounts from environmental foundations, Universities, and private individuals unassociated with the fishing industry. In addition, I receive funding from environmental NGOs, including over the years the National Resources Defense Council, The Nature Conservancy, Environmental Defense Fund, and the Pew Institute for Ocean Science.

Here is my response to those who say this means you should not believe what I say about fisheries:

Science is collaborative, not individual

When I say that all fish will not be gone by 2048 or that fish stocks are increasing in abundance in much of the world, these are not personal opinions, but results of scientific papers authored by a large group of people, each of whom stands by the results of the paper.

When the claim that “all fish would be gone by 2048” came out, the lead author on that paper, Boris Worm, and I agreed to meet together to understand why we had different perspectives. We organized a group of about 20 scientists and looked at trends in fish stock abundance where it was measured and found no sign that these stocks were generally declining. In 2009, we published a paper in Science Magazine showing this, and the lead author was Boris Worm. It is absurd to say that because I, one of 21 authors, had received funding from the fishing industry this work was biased.

I was the first author on the 2020 follow-up paper in Proceedings of the National Academy of Sciences, Effective fisheries management instrumental in improving fish stock status, that showed that fish stocks were actually increasing in much of the world, but this paper had 23 authors, including professors from several different universities, an employee of The Nature Conservancy, a member of the Board of Directors of The Nature Conservancy, a member of the Board of Directors of Environmental Defense, and an employee of the Wildlife Conservation Society all of whom stand by our conclusions. It is not my work, but group work, and where I get some of my funding is largely irrelevant.

Almost every paper with my name on it in fisheries has a range of authors and many of them have at least one author representing conservation organizations.

Look at the data and what was actually done

My research is not cloaked in secrecy. In every research paper I have been a part of, we tell the reader what data we used and how we used it to get the results we did. This is the methodology section. We describe our data and methods so you, or anyone else, can redo and/or verify the analysis.

This is an important part of science. I have criticized the methodology section of others before, and others have criticized mine—this is what makes information evolve closer to truth. Unfortunately, that part of science gets lost in press releases and hyperbolic headlines, which was a large reason I started this website—to explain the methodology sections of important fisheries papers to give the public (and journalists) proper context. For example, we have been highly critical of Oceana’s seafood fraud methodology on this website, but we appreciate the work they do and gave them a platform to respond to our criticism.

Read the full story at Sustainable Fisheries UW

Dr. Hilborn: No-take MPAs “do nothing to mitigate” problems facing U.S. oceans

November 18, 2020 (Saving Seafood) — WASHINGTON — Yesterday, at a House Natural Resources Committee hearing on the Ocean-Based Climate Solutions Act, respected fisheries scientist Dr. Ray Hilborn criticized the marine protected area (MPA) provision of the bill, which he called “the wrong tool for adapting to climate change.”

The provision, known as the “30 by 30” plan, would require the establishment of MPAs in at least 30 percent of American waters by 2030. In his testimony, Dr. Hilborn, professor of sustainable fisheries at the University of Washington, cited numerous threats facing U.S. oceans, including climate change, ocean acidification, exotic species, land-based runoff, plastics and illegal fishing.

“There are solutions to each of these problems,” Dr. Hilborn said. “But it is not no-take MPAs – they do nothing to mitigate these problems.”

Dr. Hilborn praised current fisheries management under the regional council process, which he called science-based and credible with industry and other stakeholders. He also pointed out that MPAs would simply push fishing pressure outside of the protected area into other parts of the ocean, with no net gain.

“MPA advocates ignore the fact that ‘30 by 30’ would cause 70 percent of U.S. oceans to see increased fishing pressure from the vessels that moved out of the 30 percent closed, and thus potentially be less resilient to climate change. Do we really want to make 70 percent of our oceans less resilient to climate change?” Dr. Hilborn said.

The hearing kicked off with Ranking Member Rob Bishop (R-UT) introducing a letter organized in part by Saving Seafood and signed by over 800 seafood industry members opposing the “30 by 30” plan. Rep. Bishop added that “30 by 30” is “woefully misguided, does not improve fisheries, it undermines the Magnuson-Stevens Act, and even worse, it’s detrimental to Americans, especially American fishermen.”

Read Dr. Hilborn’s written testimony here

Watch the full hearing here