Saving Seafood

Counting salmon is a breeze with airborne eDNA

December 1, 2025 — During the annual salmon run last fall, University of Washington researchers pulled salmon DNA out of thin air and used it to estimate the number of fish that passed through the adjacent river. Aden Yincheong Ip, a UW research scientist of marine and environmental affairs, began formulating the driving hypothesis for the study while hiking on the Olympic Peninsula.

“I saw the fish jumping and the water splashing and I started thinking — could we recover their genetic material from the air?,” he said.

The researchers placed air filters at several sites on Issaquah Creek, near the Issaquah Salmon Hatchery in Washington. To their amazement, the filters captured Coho salmon DNA, even 10 to 12 feet from the river. Scientists collect environmental DNA, or eDNA, to identify species living in or passing through an area, but few have attempted to track aquatic species by sampling air.

This study, published Nov. 26 in Scientific Reports, shows that eDNA can move between air and water — a possibility scientists hadn’t accounted for even though aquatic animal DNA sometimes appears in airborne study data.

The researchers then merged air and water eDNA with the hatchery’s visual counts in a model to track how salmon numbers rose and fell during the fall migration. Although the amount of salmon DNA in the air was 25,000 times less than what was observed in the water, its concentration still varied with observed migratory trends.

“This work is at the edge of what is possible with eDNA,” said senior author Ryan Kelly, a UW professor of marine and environmental affairs and director of the eDNA Collaborative. “It pushes the boundaries way further than I thought we could.”

Read the full article at UW News

Underexploitation of Fish Stocks: A Greater Threat to Food Security than Overfishing

January 15, 2025 —  A groundbreaking study published by researchers at the University of Washington has unveiled fresh insights into the effectiveness of global fisheries management, challenging conventional assessments that focus solely on overfishing. The research, led by Dr. Ray Hilborn, suggests that underexploitation of fish stocks is a far more significant contributor to lost food potential than overfishing. This discovery is central to the study’s introduction of a novel metric—the Commercial Fisheries Food Production Index (CFFPI)—designed to assess the ability of fisheries to maximize sustainable food production.

Key Findings: Underutilization of Fish Stocks

The study evaluates fisheries across 19 data-rich nations and five regional fisheries management organizations (RFMOs). These nations include Iceland, the Faroe Islands, Norway, the United States, Canada, Australia, New Zealand, Chile, Argentina, South Africa, Morocco, Peru, Russia, Japan, and Turkey. The European Union is analyzed separately for its Atlantic and Mediterranean regions, while sub-Saharan Africa is also included. Among the RFMOs studied are the Western and Central Pacific Fisheries Commission (WCPFC), Indian Ocean Tuna Commission (IOTC), International Commission for the Conservation of Atlantic Tunas (ICCAT), Inter-American Tropical Tuna Commission (IATTC), and the Commission for the Conservation of Southern Bluefin Tuna (CCSBT).

The study reveals that current management practices capture only 77% of the combined maximum sustainable yield (MSY) from fish stocks. Notably, the research attributes 86% of the unrealized food production to insufficient fishing pressure, while overfishing accounts for a mere 14%.

Among international fisheries, the pattern is consistent: the majority of lost potential stems from underexploitation, not overfishing. These findings challenge traditional methods of evaluating fisheries performance, which prioritize preventing overfishing without adequately addressing opportunities to sustainably increase food production.

Introducing the CFFPI

To provide a more holistic assessment, the researchers developed the CFFPI. This index evaluates the long-term food production achievable from fisheries under current management compared to their maximum potential. Unlike conventional metrics focused on stock abundance, the CFFPI emphasizes fishing pressure as the critical variable for maximizing sustainable food production.

By using the CFFPI, the researchers identified that many countries could significantly increase their food production by targeting underexploited stocks, although this may require balancing other objectives such as environmental conservation and employment.

Broader Implications for Fisheries Policy

The study underscores the need to expand fisheries assessments beyond the commonly reported metrics of overfished stocks. While avoiding overfishing remains essential, the researchers argue that increasing fishing pressure on underexploited stocks offers a path to achieving higher sustainable yields. However, implementing such changes will require careful alignment with national and international goals, including ecological sustainability and economic priorities.

The analysis also highlights stark differences in management effectiveness among countries. Iceland, the Faroe Islands, and Norway scored highly on the CFFPI, reflecting their focus on optimizing yields. In contrast, nations like the United States and Australia, often praised for their strong environmental laws, showed lower CFFPI scores due to precautionary policies that maintain low fishing pressure to avoid ecological risks.

A Call for Holistic Evaluation

The researchers conclude by advocating for the adoption of the CFFPI as a standard measure in fisheries management evaluations. Dr. Hilborn emphasizes that the index provides a more nuanced understanding of fisheries performance, accounting for the trade-offs inherent in managing marine resources for food production, environmental health, and socio-economic benefits.

“Simply reporting the proportion of stocks overfished or subject to overfishing, as is commonly done, does not, by itself, provide an adequate basis for decision-making when fisheries management has multiple objectives,” the authors state.

As global food security challenges intensify, this study provides a critical framework for optimizing fisheries management. By adopting tools like the CFFPI, policymakers can ensure that fisheries fulfill their potential as vital contributors to sustainable food systems while balancing ecological and social priorities.

Read the full article here

Scientists unearth key clues to cuisine of resident killer whale populations

September 21, 2024 — A team led by researchers at the University of Washington and the National Oceanic and Atmospheric Administration has uncovered key information about what resident killer whale populations are eating. Researchers had long known that resident killer whales—also known as resident orcas—prefer to hunt fish, particularly salmon. But some populations thrive, while others have struggled. Scientists have long sought to understand the role that diet plays in these divergent fates.

“Killer whales are incredibly intelligent, and learn foraging strategies from their matriarchs, who know where to find the richest prey resources in their regions,” said Amy Van Cise, UW assistant professor of aquatic and fishery sciences, who began this study as a postdoctoral researcher with NOAA’s Northwest Fisheries Science Center. “So we wanted to know: Does all of that social learning affect  preferences in different populations of resident killer whales, or in pods within populations?”

In a paper published in the journal Royal Society Open Science, Van Cise and her colleagues report the cuisine preferences of two resident killer whale populations: the Alaska residents and the southern residents, which reside primarily in the Salish Sea and off the coast of Washington, Oregon and northern California.

Read the full article at PHYS.org

Thanks to humans, Salish Sea waters are too noisy for resident orcas to hunt successfully

September 11, 2024 — The Salish Sea—the inland coastal waters of Washington and British Columbia—is home to two unique populations of fish-eating orcas, the northern resident and the southern resident orcas. Human activity over much of the 20th century, including reducing salmon runs and capturing orcas for entertainment purposes, decimated their numbers. This century, the northern resident population has steadily grown to more than 300 individuals, but the southern resident population has plateaued at around 75. They remain critically endangered.

New research led by the University of Washington and the National Oceanic and Atmospheric Administration has revealed how underwater noise produced by humans may help explain the southern residents’ plight. In a paper published Sept. 10 in Global Change Biology, the team reports that  pollution—from both large and small vessels—forces northern and southern  orcas to expend more time and energy hunting for fis

Read the full article at PHYS.org

Hilborn lab finds counterevidence to study claiming MPAs have “spillover” effect

April 2, 2o23 — A new analysis by the University of Washington’s Sustainable Fisheries Lab is countering a study that claims the Papahānaumokuākea Marine National Monument, the largest marine protected area (MPA) in the U.S., caused a “spillover effect” in yellowfin tuna.

The study, “Spillover benefits from the world’s largest fully protected MPA,” claimed it found “clear evidence” of spillover effects for both bigeye and yellowfin tuna. A spillover effect refers to when the population of a particular species in an MPA becomes so abundant that it “spills over” into surrounding areas that can be targeted by fishermen.

Read the full article at SeafoodSource

University of Washington research aiding salmon run forecasting in Alaska

May 25, 2022 — The Bristol Bay Regional Seafood Development Association (BBRSDA) and the University of Washington Alaska Salmon Program hosted a webinar on Thursday, 5 May, to present their 2022 salmon forecast for Bristol Bay, as well as ongoing research into run timing, environmental impacts, and fish and climate trends in the bay.

Founded in 2005, the BBRSDA is an organization established by Bristol Bay fishermen to support all aspects of the sockeye salmon fishery, from marketing and infrastructure to research and education. The University of Washington’s Alaska Salmon Program has partnered with BBRSDA to research the Pacific salmon fisheries of Alaska in an effort to gain understanding of the changing ecosystems and provide knowledge necessary to management and conservation.

Read the full story at SeafoodSource

 

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

 

Retraction of Flawed Study Implies Larger Problems with Science Used to Support Creation of MPAs

December 14, 2021 — A scientific paper (Cabral et al. 2020, A global network of marine protected areas for food) that claimed that closing an additional 5% of the ocean to fishing would increase fish catches by 20% has been retracted by Proceedings of the National Academy of Sciences of the United States of America (PNAS), the journal in which it was published.

At the time of publication, the paper’s findings were immediately covered by The Economist (Stopping some fishing would increase overall catches) and Forbes (Protecting 5% More Of The Ocean Can Increase Fisheries Yield By 20% According To New Research) and other mainstream outlets, including the New York Times, Axios, National Geographic, and The Hill.

Representative Deb Haaland, now the Secretary of the Interior, who recently restored Obama-era prohibitions on fishing in the Northeast Canyons and Seamounts Marine National Monument without scientific or economic review — and without meeting with affected fishermen —  submitted the now-retracted paper as supporting evidence for the “30×30” provisions of the Ocean-Based Climate Solutions Act. The provision calls on the federal government to conserve at least 30% of Federal waters by the year 2030. (For a longer critique of the 30×30 initiative see this piece by Dr. Roger Mann of the Virginia Institute of Marine Science at the College of William and Mary).

It has since been determined that the paper had both conflict of interest as well as data and model assumption problems.

PNAS determined that the person responsible for assigning Cabral et al.’s peer reviewers, Dr. Jane Lubchenco, currently White House Deputy Director for Climate and Environment, had a conflict of interest. According to the editor-in-chief of PNAS, the frequent collaboration relationship Lubchenco had with the paper’s authors constituted a conflict of interest, as did her personal relationship with one of the authors, Dr. Steve Gaines—her brother-in-law.

Several close collaborators of the Cabral et al. group wrote scientific critiques that pointed out errors and impossible assumptions that suggested the paper was inadequately peer reviewed.

According to an analysis of the paper from Sustainable Fisheries at the University of Washington:

Cabral et al. 2020 assembled a computer model out of several kinds of fishery data to predict where marine protected areas (MPAs) should be placed to maximize global sustainable seafood production. MPAs meant to increase food production do so by reducing fishing pressure in places where it is too high (overfishing). Asia and Southeast Asia have some of the highest overfishingrates in the world—reducing fishing pressure there is a no-brainer, but the model determined many of those areas to be low priority for protection.  The results should have been red flag for the peer reviewers of Cabral et al. 2020. Why were MPAs prioritized all around the U.S., where overfishing has been practically eliminated, but not prioritized around India, Thailand, Indonesia, Malaysia, Vietnam, and China?

Clearly, something was wrong with the model.

For more about the problems with this paper, as well as a look at concerns with another headline-grabbing study that suggested carbon emissions from bottom trawl fishing are similar to emissions from global aviation, see the Sustainable Fisheries analysis here.

 

ALASKA: More than 70 million sockeye salmon expected in Bristol Bay next year, potentially busting this year’s record

December 8, 2021 — If the forecasts are close to accurate, this year’s Bristol Bay sockeye run won’t be a record for long.

Biology teams with University of Washington and the Alaska Department of Fish and Game both expect more than 70 million sockeye to return to Bristol Bay for the first time in recorded history.

Daniel Schindler, a biologist with UW’s Alaska Salmon Program, said multiple factors in the university’s record run forecast bolster its credibility. For one, all of the Bay’s nine large river systems are predicted to do very well, rather than just one or two forecasted to have outsized sockeye returns. The fact that the 2022 run will be on the heels of an inshore run of approximately 66.1 million sockeye — the all-time record — which provides researchers more to go on as well, according to Schindler.

Both the UW and Fish and Game forecasts are a weighted average of several models that use what are known as sibling relationships to formulate predictions, largely based on how many salmon of certain age classes returned in prior years.

Read the full story at the Anchorage Daily News