Saving Seafood

Webinar Recording Available: Crafting Guidance for Adapting to Shifting Fish Populations

May 13, 2019 — The following was released by Lenfest Ocean Program:

What lessons can be learned from the management practices in other regions and nations to inform allocation strategies for shifting stocks along the U.S. Northeast and Mid-Atlantic coasts? On Tuesday, April 23, the Lenfest Ocean Program hosted a webinar featuring Dr. Andrew Pershing and his colleagues from the Gulf of Maine Research Institute to discuss their project characterizing different fishery allocation systems from around the world and their potential for application in the U.S.

The recording for the one-hour webinar is now available online and can be accessed on the Lenfest Ocean Program website. To share your own experience with fishery allocation issues under climate change, or if you have questions, comments or suggestions on the study, please complete this survey. Feel free to email Willy Goldsmith (wgoldsmith@lenfestocean.org) with any further questions.

REMINDER: April 23 Webinar on Fishery Allocation Under Climate Change

April 19, 2019 — The following was released by the Lenfest Ocean Program:

How should harvest of valuable fish stocks be allocated as populations shift due to climate change? What lessons can be learned from the management practices in other regions and nations to inform allocation strategies for shifting stocks along the U.S. Northeast and Mid-Atlantic coasts? On Tuesday, April 23, at 2:00 PM Eastern time/11:00 AM Pacific time the Lenfest Ocean Program will host a webinar featuring Dr. Andrew Pershing, Dr. Lisa Kerr, Mr. Jonathan Labaree, and Dr. Kanae Tokunaga, all of the Gulf of Maine Research Institute, to discuss their project characterizing different fishery allocation systems from around the world and their potential for application in the U.S. Download the fact sheet to learn more about this project.

Click here to register

Webinar Instructions:

  • Date: Tuesday, April 23, 2019
  • Time: 2:00 PM Eastern time/11:00 AM Pacific time

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  • Event number: 791 597 316
  • Event password: StockShifts2019

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‘Rule of Thumb’ Management Approach Is Wrong For Forage Fish, Dr. Ray Hilborn Tells U.S. Senate Subcommittee

WASHINGTON (Saving Seafood) – October 31, 2017 – At a hearing of the U.S. Senate Commerce Subcommittee on Oceans, Atmosphere, Fisheries and Coast Guard last week, respected fisheries scientist Dr. Ray Hilborn testified that fisheries managers “can do better than a one-size-fits-all” approach to managing forage fish. He also said there was “no empirical evidence to support the idea that the abundance of forage fish affects their predators.”

Dr. Hilborn’s comments came in response to questioning from Sen. Roger Wicker (R-MS) about whether fisheries managers should manage forage fish according to a “rule of thumb” approach, where fisheries are managed according to a set of broad ecological and management principals, or a “case-by-case” approach, where management is guided by more species-specific information.

Dr. Hilborn, a professor at the University of Washington’s School of Aquatic and Fishery Sciences, was part of a team of top fisheries scientists that recently examined these issues, as well as what effects fishing for forage fish species had on predator species. Their research indicated that previous studies, like a 2012 report from the Lenfest Forage Fish Task Force, may have overestimated the strength of the predator-prey relationship.

Before the hearing, Dr. Hilborn spoke with Saving Seafood about his research and his message for lawmakers.

“It’s very clear that there really are no applicable rules of thumb, that every system is independent [and] behaves differently, and we need to have the rules for each individual forage fish fishery determined by looking at the specifics of that case,” Dr. Hilborn told Saving Seafood.

He also discussed his team’s finding that forage fish abundance has little impact on their predators. They looked at nearly all U.S. forage fish fisheries, including the California Current system and Atlantic menhaden, and concluded that predator species generally pursue other food sources when the abundance of any one forage species is low.

“The predators seem to go up or down largely independent of the abundance of forage fish,” Dr. Hilborn said, adding, “For Atlantic menhaden, for their major predators, the fishery has reasonably little impact on the food that’s available to them.”

Another key message Dr. Hilborn had for the Subcommittee was that fisheries managers must determine what they want to accomplish so that scientists can advise them accordingly.

“The time has come to refocus our fisheries policy on what we actually want to achieve because rebuilding is only a means to an end,” Dr. Hilborn told Saving Seafood. “Do we want to maximize the economic value of our fisheries? Do we want to maximize jobs? Do we want to maximize food production?”

In his testimony, Dr. Hilborn praised U.S. fisheries policy that has “led to rebuilding of fish stocks and some of the most successful fisheries in the world.” He attributed this success to a variety of factors, including funding of NOAA, regionalizing fisheries management decisions, and requiring managers to follow science advice. As a result, overfishing should no longer be the top priority for fisheries managers, he testified.

“The major threats to U.S. fish stock and marine ecosystem biodiversity are now ocean acidification, warming temperatures, degraded coastal habitats, exotic species, land based run off, and pollution,” Dr. Hilborn testified. “Overfishing remains a concern for a limited number of stocks but should not continue to be the most important concern for U.S. federal fisheries policy.”

The hearing was the latest in a series examining reauthorization of the Magnuson-Stevens Fishery Conservation and Management Act, the nation’s supreme fisheries law. It was organized by subcommittee chairman Sen. Dan Sullivan (R-AK), and focused on fisheries science.

Watch the full hearing here

Authors of Recent Research on Forage Fish Respond to Criticism from Lenfest Task Force

WASHINGTON – September 20, 2017 – In April, a team of respected fisheries scientists led by Dr. Ray Hilborn published a study that found fishing of forage species likely has a lower impact on predators than previously thought. This conclusion challenged previous forage fish research, most notably the 2012 Lenfest Oceans Program report “Little Fish, Big Impact,” which recommended leaving more forage fish in the water to be eaten by predators.

The Lenfest task force responded to this new research with a Letter to the Editor of Fisheries Research, where the Hilborn et al. study was published. In response to this letter, Hilborn et al. wrote their own letter, which was published August 5 in Fisheries Research and is reproduced below:

Our paper highlighted that key biological relationships between forage fish and their predators were not included in the models used in the LENFEST report. These missing elements were (1) the high level of natural variability of forage fish, (2) the weak relationship between forage fish spawning stock size and recruitment and the role of environmental productivity regimes, (3) the size distribution of forage fish, their predators and subsequent size selective predation and (4) the changes in spatial distribution of the forage fish as it influences the reproductive success of predators. We demonstrate that each of these elements can have a major impact on how one evaluates the impact of fishing forage species on their predators. The LENFEST report used EwE models without these factors to determine the very specific recommendations they made about how to manage forage fish.

We certainly agree that in some cases fishing forage fish will affect their predators, but in other cases there may be little if any impact – it all depends on the biology that was not included in the models used.

This critique of our paper suggests that we are offering alternative evaluation of the impact of fishing forage fish that are, like the LENFEST recommendations, broadly applicable. We make no such claim and much of their critique is against the straw man they have constructed. We are not arguing that fishing forage fish does not affect predators. Rather we show how, in specific cases, there may be little if any impact of fishing forage fish and that general conclusions simply are not possible.

We suggest that the very specific quantitative measures proposed in the LENFEST report result from models that do not have these components and that if these elements were included in the models the conclusions would likely be different. While the authors of the letter argue that they conducted a comprehensive literature review, the specific recommendations came from their modelling, and it is the modelling we criticize and their critique makes few attempts to defend.

We stated “Pikitch et al. (2012) argued forcefully that their analysis provided general conclusions that should be broadly applied. However, relevant factors are missing from the analysis contained in their work…” Their response is that their recommendations were “tailored to the level of uncertainty and data availability of each system.” What we refer as “general conclusions” contain a set of recommendations for three uncertainty tiers, but our point is that the biology of each system is different, not the availability of data or uncertainty, and the differences in biology should be considered when evaluating management options for forage fisheries.

The specificity of their recommendations is clear – for high information situations (which would include the California Current, Humboldt Current, NE Atlantic sand eel and herring) their recommendation is “In any case, lower biomass limits should not be less than 0.3 B0, an MAX F should not exceed 0.75 FMSY or 0.75 M.” These numbers are not the result of their case studies or literature review but the result of their models that did not include a number of important elements.

Finally, we agree that situations where detailed information is lacking are challenging for management, and that is why it is important to identify species and system attributes that make systems less resilient to fishing. Low trophic level species constitute the largest potential sources of increased fish production in the world and much of the recent suggestions for “balanced harvesting” relies on significant increases in exploitation rates on trophic levels associated with forage fish. Since almost all of these potential low trophic level species would be considered in the “low information tier” the LENFEST recommendation is that new fisheries not be allowed until sufficient data are collected. Given that few countries will devote resources to research on fisheries that do not exist, the LENFEST recommendation essentially says no new fisheries on these species, and thus in effect precludes development of what may be significant food resources.

We believe the authors of our paper and the LENFEST report all accept that in some cases predators may be highly dependent on forage fish, but in other cases there may be little dependence. Management should be based upon what is known about the dependence of the predators on forage fish and the relative importance the local agencies place on maintaining high predator abundance verses the benefits of full exploitation of the forage fish. The major forage fisheries of the world are very valuable and currently intensively studied. What is needed for each of these fisheries is a new set of models that incorporate the elements that were missing from the LENFEST analysis.

Ray Hilborn, Ricardo O. Amoroso, Eugenia Bogazzi, Olaf P. Jensen, Ana M. Parma, Cody Szuwalski, Carl J. Walters

D.B. Pleschner: Study: No correlation between forage fish, predator populations

April 10, 2017 — On April 9-10, the Pacific Fishery Management Council is meeting in Sacramento to deliberate on anchovy management and decide on 2017 harvest limits for sardine, two prominent west coast forage fish.

Extreme environmental groups like Oceana and Pew have plastered social media with allegations that the anchovy population has crashed, sardines are being overfished and fisheries should be curtailed, despite ample evidence to the contrary.

Beyond multiple lines of recent evidence that both sardines and anchovy populations are increasing in the ocean, a new study published this week in the journal Fisheries Research finds that the abundance of these and other forage fish species is driven primarily by environmental cycles with little impact from fishing, and well-managed fisheries have a negligible impact on predators — such as larger fish, sea lions and seabirds.

This finding flies directly in the face of previous assumptions prominent in a 2012 study commissioned by the Lenfest Ocean Program, funded by the Pew Charitable Trusts, heirs of Sun Oil Company. The Lenfest study concluded that forage fish are twice as valuable when left in the water to be eaten by predators and recommended slashing forage fishery catch rates by 50 to 80 percent.

However, in the new study, a team of seven internationally respected fisheries scientists, led by Prof. Ray Hilborn, Ph.D., of the University of Washington, discovered no correlation between predator populations and forage fish abundance. The new research also found multiple omissions in the methodology of the Lenfest study. For instance, it — and other previous studies — used ecosystem models that ignored the natural variability of forage fish, which often fluctuate greatly in abundance from year-to-year.

Read the full opinion piece at the Santa Cruz Sentinel

New Study Challenges Earlier Findings Regarding Link Between Predators, Forage Fish

WASHINGTON (Saving Seafood) – April 3, 2017 – A new study published today in Fisheries Research finds that fishing forage fish may have a smaller impact on their predators than previously thought. The study, authored by a team of marine scientists led by renowned University of Washington fisheries expert Dr. Ray Hilborn, calls into question previous forage fish research that may have overestimated the effect of fishing of forage fish on their predators.

The study, “When does fishing forage species affect their predators?,” finds that changes in predator populations are largely unrelated to the abundance of forage fish. It also shows that the distribution of forage fish is more important to predators than their overall abundance, and that many predators prefer smaller forage fish that are largely unaffected by fishing. Based on these results, the authors recommend that forage fishing policies be created on a case-by-case basis.

The paper’s findings point to issues with previous forage fish research, most notably a five-year-old study funded by the Lenfest Ocean Program, managed by The Pew Charitable Trusts, which it says failed to consider important variables like the spatial distribution of forage fish. Arguably the largest oversight in past research was the high natural variability of forage fish populations, even in the absence of fishing, the authors write.

“There is little evidence for a strong connection between forage fish abundance and the rate of change in the abundance of predators,” the authors write. “The fact that few of the predator populations evaluated in this study have been decreasing under existing fishing policies suggests that current harvest strategies do not threaten the predators and there is no pressing need for more conservative management of forage fish.”

The authors suggest that the lack of a strong relationship between forage fish and their predators is the result of “diet flexibility” – the idea that predators can switch between prey species, helping them defend against the high natural variability of forage fish populations.

This finding contradicts the widely reported conclusions of the Lenfest Forage Fish Task Force in 2012. The study, “Little Fish, Big Impact,” claimed that forage fish are twice as valuable to humans when they are left in the water, rather than fished, because of their great importance to predator species. Based on this conclusion, the Lenfest group recommended cutting forage fish catch rates across the board by 50 to 80 percent.

But Dr. Hilborn and his coauthors advocate for a more nuanced approach, writing that previous models “were frequently inadequate for estimating impact of fishing forage species on their predators” and that “a case by case analysis is needed.” The team explicitly calls into question the Lenfest study’s recommendations, which it says are “not appropriate for all species.”

“Relevant factors are missing from the analysis contained in [the Lenfest] work, and this warrants re-examination of the validity and generality of their conclusions,” the authors write. “We have illustrated how consideration of several factors which they did not consider would weaken the links between impacts of fishing forage fish on the predator populations.”

These missing elements include how fishing mortality compares with the natural variability of forage species, the spatial structure of forage fish populations, and the overlap between the sizes of forage fish eaten by predators and size taken by the fishery.

“It must be remembered that small pelagic fish stocks are a highly important part of the human food supply, providing not only calories and protein, but micronutrients, both through direct human consumption and the use of small pelagics as food in aquaculture,” the paper concludes. “Some of the largest potential increases in capture fisheries production would be possible by fishing low trophic levels much harder than currently.”

Read an infographic about the study here 

Watch a video about the study here 

Hilborn Study Redefines Forage Fish Predator Relationships; Suggests Fishing Pressure Lesser Factor

April 3, 2017 — SEAFOOD NEWS — New research published today in the journal Fisheries Research finds that fishing of forage species likely has a lower impact on predators than previously thought, challenging previous studies that argued forage fish are more valuable left in the ocean.

In 2012 a Lenfest study got wide play claiming that models showed fishing pressure on prey species had big impacts on the abundance of predator species, such as cod and tuna.  However, some of the authors of the original model have now joined with other researchers to say it is out of date.

A team of seven respected fisheries scientists, led by Prof. Ray Hilborn, Ph. D., of the University of Washington, found that predator populations are less dependent on specific forage fish species than assumed in previous studies including a 2012 study commissioned by the Lenfest Ocean Program is managed by The Pew Charitable Trusts. The Lenfest Forage Fish Task Force argued that forage fish are twice as valuable when left in the water to be eaten by predators, and recommended slashing forage fish catch rates by 50 to 80 percent.

For fisheries management, such a precautionary approach would have a large impact on the productivity of forage fisheries. As groups such as IFFO (The Marine Ingredients Organisation) have noted, these stocks contribute strongly to global food security, as well as local and regional social and economic sustainability.

However, the new research found multiple omissions in the methodology of the Lenfest study. “When you review the actual models that were used [by Lenfest], there are a few key elements on the biology of these animals that were not represented, ” said Dr. Ricardo Amoroso, one of the study’s co-authors. He added that one of the authors’ approaches was to “look for empirical evidence of what is actually happening in the field. ” Previous studies relied on models which took for granted that there should be a strong link between predators and prey.

Specifically, the Lenfest study and another study using ecosystem models ignored the natural variability of forage fish, which often fluctuate greatly in abundance from year to year. It also failed to account for the fact that predators tend to eat smaller forage fish that are largely untouched by fishermen. Because of these oversights, the new study concluded that the Lenfest recommendations were overly broad, and that fisheries managers should consider forage species on a case-by-case basis to ensure sound management.

“It is vital that we manage our fisheries to balance the needs of the ecosystem, human nutrition and coastal communities, ” said Andrew Mallison, IFFO Director General. “These findings give fishery managers guidance based on science, and update some of the inaccurate conclusions of previous reports. ”

The Lenfest findings were largely based on a model called EcoSim, developed by Dr. Carl J. Walters, one of the co-authors of the new paper. Dr. Walters found that the EcoSim models used in earlier studies had omitted important factors, including natural variability, recruitment limitations and efficient foraging of predators.

Dr. Walters noted that there were “very specific” issues with previous uses of the EcoSim model. “It was predicting much higher sensitivity of creatures at the top of the food webs to fishing down at the bottom than we could see in historical data, ” he said.

This is not the first time ecosystem models used in earlier studies have been questioned. One year after the Lenfest study was completed, two of its authors, Dr. Tim Essington and Dr. Éva Plagányi, published a paper in the ICES Journal of Marine Science where they said, “We find that the depth and breadth with which predator species are represented are commonly insufficient for evaluating sensitivities of predator populations to forage fish depletion. ” The new study reaffirmed this finding, noting “several reasons to concur with the conclusion that the models used in previous analysis were insufficient. ”

In addition to its critiques of previous research, the researchers found further evidence of the lack of fishing impact on forage fish. Their research indicated that environmental factors are often much more important drivers of forage fish abundance. They also found that the distribution of forage fish has a greater impact on predators than simply the raw abundance of forage fish.

The authors concluded by noting the importance of forage fish as a part of human food supply chains, praising their high nutritional value, both through direct human consumption and as food in aquaculture, as well as the low environmental impact of forage fishing. Cutting forage fishing, as recommended by the Lenfest group, would force people to look elsewhere for the healthy protein and micronutrients provided by forage fish – likely at much greater environmental cost, the authors wrote.

“Forage fish provide some of the lowest environmental cost food in the world – low carbon footprint, no water use, ” Dr. Hilborn said. “[There are] lots of reasons that forage fish are a really environmentally friendly form of food. ”

It is also well-established that forage fisheries provide substantial health benefits to human populations through the supply of long chain omega-3 fatty acids, both directly through consumption in the form of fish oil capsules, and indirectly through animal feed for farmed fish and land animals.

This story originally appeared on Seafoodnews.com, a subscription site. It is reprinted with permission. 

Ray Hilborn study disputes previous findings on forage fish

April 3, 2017 — A new study has been published today by a scientific group led by University of Washington fisheries researcher Ray Hilborn that disputes previous findings on the impact of human and natural predation on forage fish such as anchovies, sardines and herring.

The study, published in the scientific journal Fisheries Research, found that human fishing for forage fish does not have as great an impact on the food chain as previously thought, given that humans typically catch fish of much larger size than those typically hunted and eaten by non-human species. The study also decouples the link between the size of forage fish populations and the populations of species that predate on forage fish.

“What we found is that there is essentially no relationship between how many forage fish there are in the ocean and how well predators do in terms of whether the populations increase or decrease,” Hilborn said in a video explaining the study’s findings.

The study was co-authored by the University of Washington’s Ricardo O. Amoroso and Eugenia Bogazzi, Olaf P. Jensen of Rutgers University, Ana M. Parma of the Centro Nacional Patagónico, Cody Szuwalski of the University of California Santa-Barbara and Carl J. Walters of the University of British Columbia. It was funded in part by the National Coalition for Fishing Communities and was supported by the IFFO, the marine ingredients trade group.

It takes particular fault with the methods used by a 2012 study on forage fish by the Lenfest Ocean Program, which is managed by the Pew Charitable Trusts.

“The Lenfest conclusion that predators rise and fall with their prey populations is simply not true. It’s not empirically true,” Walters, one of the authors of the original Lenfest study, said. “One of the things we did in this study was collect together a lot of time-series patterns of predator abundances and forage-fish abundances, and we just didn’t see the correlation, nor have other scientists who have looked at this objectively.”

Predators “have developed some strategy of how to cope with the natural variability” of forage fish populations, according to Amoroso, the study’s second author.

Read the full story at Seafood Source

Predators may be less affected by catch of small fish than previously thought, new study says

WASHINGTON (NCFC) – April 3, 2017 – New research published today in the journal Fisheries Research finds that fishing of forage species likely has a lower impact on predators than previously thought, challenging previous studies that argued forage fish are more valuable left in the ocean.

A team of seven respected fisheries scientists, led by Prof. Ray Hilborn, Ph.D., of the University of Washington, found that predator populations are less dependent on specific forage fish species than assumed in previous studies, most prominently in a 2012 study commissioned by the Lenfest Ocean Program, which is managed by The Pew Charitable Trusts. The Lenfest Forage Fish Task Force argued that forage fish are twice as valuable when left in the water to be eaten by predators, and recommended slashing forage fish catch rates by 50 to 80 percent.

For fisheries management, such a precautionary approach would have a large impact on the productivity of forage fisheries. As groups such as IFFO (The Marine Ingredients Organisation) have noted, these stocks contribute strongly to global food security, as well as local and regional social and economic sustainability.

However, the new research found multiple omissions in the methodology of the Lenfest study. “When you review the actual models that were used [by Lenfest], there are a few key elements on the biology of these animals that were not represented,” said Dr. Ricardo Amoroso, one of the study’s co-authors. He added that one of the authors’ approaches was to “look for empirical evidence of what is actually happening in the field.” Previous studies relied on models which took for granted that there should be a strong link between predators and prey.

Specifically, the Lenfest study and another study using ecosystem models ignored the natural variability of forage fish, which often fluctuate greatly in abundance from year to year. It also failed to account for the fact that predators tend to eat smaller forage fish that are largely untouched by fishermen. Because of these oversights, the new study concluded that the Lenfest recommendations were overly broad, and that fisheries managers should consider forage species on a case-by-case basis to ensure sound management.

“It is vital that we manage our fisheries to balance the needs of the ecosystem, human nutrition and coastal communities,” said Andrew Mallison, IFFO Director General. “These findings give fishery managers guidance based on science, and update some of the inaccurate conclusions of previous reports.”

The Lenfest findings were largely based on a model called EcoSim, developed by Dr. Carl J. Walters, one of the co-authors of the new paper. Dr. Walters found that the EcoSim models used in earlier studies had omitted important factors, including natural variability, recruitment limitations and efficient foraging of predators.

Dr. Walters noted that there were “very specific” issues with previous uses of the EcoSim model. “It was predicting much higher sensitivity of creatures at the top of the food webs to fishing down at the bottom than we could see in historical data,” he said.

This is not the first time ecosystem models used in earlier studies have been questioned. One year after the Lenfest study was completed, two of its authors, Dr. Tim Essington and Dr. Éva Plagányi, published a paper in the ICES Journal of Marine Science where they said, “We find that the depth and breadth with which predator species are represented are commonly insufficient for evaluating sensitivities of predator populations to forage fish depletion.” The new study reaffirmed this finding, noting “several reasons to concur with the conclusion that the models used in previous analysis were insufficient.”

In addition to its critiques of previous research, the researchers found further evidence of the lack of fishing impact on forage fish. Their research indicated that environmental factors are often much more important drivers of forage fish abundance. They also found that the distribution of forage fish has a greater impact on predators than simply the raw abundance of forage fish.

The authors concluded by noting the importance of forage fish as a part of human food supply chains, praising their high nutritional value, both through direct human consumption and as food in aquaculture, as well as the low environmental impact of forage fishing. Cutting forage fishing, as recommended by the Lenfest group, would force people to look elsewhere for the healthy protein and micronutrients provided by forage fish – likely at much greater environmental cost, the authors wrote.

“Forage fish provide some of the lowest environmental cost food in the world – low carbon footprint, no water use,” Dr. Hilborn said. “[There are] lots of reasons that forage fish are a really environmentally friendly form of food.”

It is also well-established that forage fisheries provide substantial health benefits to human populations through the supply of long chain omega-3 fatty acids, both directly through consumption in the form of fish oil capsules, and indirectly through animal feed for farmed fish and land animals.

The paper was authored by Dr. Ray Hilborn, Dr. Ricardo O. Amoroso, and Dr. Eugenia Bogazzi from the University of Washington; Dr. Olaf P. Jensen from Rutgers University; Dr. Ana M. Parma from Center for the Study of Marine Systems -CONICET, Argentina; Dr. Cody Szuwalski from the University of California Santa Barbara; and Dr. Carl J. Walters from the University of British Columbia.

Read the full study here

Watch a video about the study here

Read an infographic about the study here

Predators may be less affected by catch of small fish than previously thought, new study says

April 3, 2017 — WASHINGTON — The following was released by the National Coalition for Fishing Communities and IFFO: 

New research published today in the journal Fisheries Research finds that fishing of forage species likely has a lower impact on predators than previously thought, challenging previous studies that argued forage fish are more valuable left in the ocean.

A team of seven respected fisheries scientists, led by Prof. Ray Hilborn, Ph.D., of the University of Washington, found that predator populations are less dependent on specific forage fish species than assumed in previous studies, most prominently in a 2012 study commissioned by the Lenfest Ocean Program, which is managed by The Pew Charitable Trusts. The Lenfest Forage Fish Task Force argued that forage fish are twice as valuable when left in the water to be eaten by predators, and recommended slashing forage fish catch rates by 50 to 80 percent.

 For fisheries management, such a precautionary approach would have a large impact on the productivity of forage fisheries. As groups such as IFFO (The Marine Ingredients Organisation) have noted, these stocks contribute strongly to global food security, as well as local and regional social and economic sustainability.

 However, the new research found multiple omissions in the methodology of the Lenfest study. “When you review the actual models that were used [by Lenfest], there are a few key elements on the biology of these animals that were not represented,” said Dr. Ricardo Amoroso, one of the study’s co-authors. He added that one of the authors’ approaches was to “look for empirical evidence of what is actually happening in the field.” Previous studies relied on models which took for granted that there should be a strong link between predators and prey.

 Specifically, the Lenfest study and another study using ecosystem models ignored the natural variability of forage fish, which often fluctuate greatly in abundance from year to year. It also failed to account for the fact that predators tend to eat smaller forage fish that are largely untouched by fishermen. Because of these oversights, the new study concluded that the Lenfest recommendations were overly broad, and that fisheries managers should consider forage species on a case-by-case basis to ensure sound management.

 “It is vital that we manage our fisheries to balance the needs of the ecosystem, human nutrition and coastal communities,” said Andrew Mallison, IFFO Director General. “These findings give fishery managers guidance based on science, and update some of the inaccurate conclusions of previous reports.”

 The Lenfest findings were largely based on a model called EcoSim, developed by Dr. Carl J. Walters, one of the co-authors of the new paper. Dr. Walters found that the EcoSim models used in earlier studies had omitted important factors, including natural variability, recruitment limitations and efficient foraging of predators.

Dr. Walters noted that there were “very specific” issues with previous uses of the EcoSim model. “It was predicting much higher sensitivity of creatures at the top of the food webs to fishing down at the bottom than we could see in historical data,” he said.

This is not the first time ecosystem models used in earlier studies have been questioned. One year after the Lenfest study was completed, two of its authors, Dr. Tim Essington and Dr. Éva Plagányi, published a paper in the ICES Journal of Marine Science where they said, “We find that the depth and breadth with which predator species are represented are commonly insufficient for evaluating sensitivities of predator populations to forage fish depletion.” The new study reaffirmed this finding, noting “several reasons to concur with the conclusion that the models used in previous analysis were insufficient.”

In addition to its critiques of previous research, the researchers found further evidence of the lack of fishing impact on forage fish. Their research indicated that environmental factors are often much more important drivers of forage fish abundance. They also found that the distribution of forage fish has a greater impact on predators than simply the raw abundance of forage fish. 

The authors concluded by noting the importance of forage fish as a part of human food supply chains, praising their high nutritional value, both through direct human consumption and as food in aquaculture, as well as the low environmental impact of forage fishing. Cutting forage fishing, as recommended by the Lenfest group, would force people to look elsewhere for the healthy protein and micronutrients provided by forage fish – likely at much greater environmental cost, the authors wrote.

“Forage fish provide some of the lowest environmental cost food in the world – low carbon footprint, no water use,” Dr. Hilborn said. “[There are] lots of reasons that forage fish are a really environmentally friendly form of food.”

It is also well-established that forage fisheries provide substantial health benefits to human populations through the supply of long chain omega-3 fatty acids, both directly through consumption in the form of fish oil capsules, and indirectly through animal feed for farmed fish and land animals. 

The paper was authored by Dr. Ray Hilborn, Dr. Ricardo O. Amoroso, and Dr. Eugenia Bogazzi from the University of Washington; Dr. Olaf P. Jensen from Rutgers University; Dr. Ana M. Parma from Center for the Study of Marine Systems -CONICET, Argentina; Dr. Cody Szuwalski from the University of California Santa Barbara; and Dr. Carl J. Walters from the University of British Columbia.

Read the full study here

Watch a video about the study here

Read an infographic about the study here

About the NCFC

The National Coalition for Fishing Communities provides a national voice and a consistent, reliable presence for fisheries in the nation’s capital and in national media. Comprised of fishing organizations, associations, and businesses from around the country, the NCFC helps ensure sound fisheries policies by integrating community needs with conservation values, leading with the best science, and connecting coalition members to issues and events of importance. For more, visit www.fisheriescoalition.org.

About IFFO

IFFO represents the marine ingredients industry worldwide. IFFO’s members reside in more than 50 countries, account for over 50% of world production and 75% of the fishmeal and fish oil traded worldwide. Approximately 5 million tonnes of fishmeal are produced each year globally, together with 1 million tonnes of fish oil. IFFO’s headquarters are located in London in the United Kingdom and it also has offices in Lima, Peru, and in Beijing, China. IFFO is an accredited Observer to the UN Food and Agriculture Organisation (FAO). To find out more, visit www.iffo.net.

PRESS CONTACT

Robert Vanasse

National Coalition for Fishing Communities

Washington

+1 (202) 333-2628

bob@savingseafood.org

Georgie Harris

IFFO, The Marine Ingredients Organisation

London

+44 (0) 2030 539 195

gharris@iffo.net