Saving Seafood

New Study: Precautionary Catch Limits on Forage Fish Unlikely to Benefit Predators

July 6, 2021 — The following was released by the Science Center for Marine Fisheries:

A newly released study finds that, for many predator species, extra-precautionary management of forage fish is unlikely to bring additional benefits. How to manage forage fish sustainably, both by themselves and for the rest of the ecosystem, has become a much-discussed topic in fisheries management, with regulators of several forage fisheries beginning to adopt precautionary strategies on the premise that they will better provide for the needs of predator species including seabirds, marine mammals, and fish.

The study, from Drs. Chris Free of the University of California-Santa Barbara, Olaf Jensen of the University of Wisconsin-Madison, and Ray Hilborn of the University of Washington, examines decades of historical abundance data of both forage species and their predators, and uses mathematical models to determine to what extent predator populations benefited from increasing abundance of their forage fish prey. Of the 45 predator populations examined, only 6, or 13 percent, were positively influenced by extra forage.

“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,” said Dr. Free. “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.”

The results have important implications for how strictly to manage forage fisheries. The study finds that, at least in forage fisheries that are already being well managed and are closely monitored, adopting additional precautionary measures will “rarely” provide any additional benefits to predator population growth. However, fishery managers who deal with less well-monitored fisheries may consider more precautionary strategies.

“In places of the world where we already have really strong, very effective fisheries management, additional limitations on forage fish catch are not likely to benefit their predators,” said Dr. Free.

“Management of forage fish populations should be based on data that are specific to that forage fish, and to their predators,” said Dr. Jensen. “When there aren’t sufficient data to conduct a population-specific analysis, it’s reasonable to manage forage fish populations for maximum sustainable yield, as we would other fish populations under the Magnuson-Stevens Act.”

According to the models used in the study, other environmental factors, such as water temperature, are more likely to influence predator populations. These results are consistent with previous efforts to examine the relationship between predator and prey populations.

“What we’ve done here that’s different from previous analyses is try to control for some of the other factors that influence predator population dynamics,” said Dr. Jensen. “In this case, we included in the models a covariate representing ocean temperature.”

SCEMFIS produced a video of the authors and independent experts discussing the results of the paper. Watch it here.

Read the full release here

Study finds protecting key ocean areas could boost total catch, fight climate change

May 19, 2021 — A new study published in Nature has found that protecting key areas of the ocean would increase overall catch, help reduce carbon emissions, and protect biodiversity.

The study, “Protecting the global ocean for biodiversity, food and climate,” found that an increase in protected areas of the ocean could potentially protect biodiversity, increase the yield of fisheries, and secure marine carbon stocks at risk from human activity. The study also found that most coastal nations have areas that, if protected, could “contribute substantially to achieving these three objectives of biodiversity protection, food provision, and carbon storage.”

Read the full story at Seafood Source

COVID-19 Took A Bite Out of US Seafood Industry

December 1, 2020 — The US seafood industry faced massive declines in the months following the emergence of the COVID-19 pandemic, and will need targeted federal assistance to recover, a new study shows.

“Seafood is part of the narrative that I would say doesn’t get as much attention as something like agriculture,” says Halley Froehlich, aquaculture and fisheries professor at the University of California, Santa Barbara and an author of the study in the journal Fish and Fisheries.

“And that certainly appears to be the case when we’re looking at something like the CARES Act, the federal funding source specifically passed to provide economic relief in the US,” she says.

That is, in large part, due to the fact that policymakers lack sufficient real-time data to see how the seafood industry has fared in the time of lockdowns and social distancing, says lead author Easton White, an ecologist at the University of Vermont.

“One difficulty is that a lot of this data isn’t released until months and years later,” White says. From the boat to the table, data is generated that must be gathered and processed before it gets released, he says.

The pandemic is a rapidly evolving situation and the seafood industry can’t afford to wait. So, to get a big-picture look at the early effects of COVID-19 on US fisheries and seafood consumption, the researchers synthesized multiple sources from across the seafood supply chain, including some unconventional real-time data sets.

Read the full story at Futurity

Fish populations are thriving in areas with intense management, global study finds

January 14, 2020 — A new study has shown that fishery management, when done well, works, and is the solution for keeping fisheries sustainable.

By looking at data from about 30 countries around the world, a group of researchers have concluded that intense fisheries management has led to healthy or improving fish populations, while a dearth of management has led to overfishing. The researchers published their results in a study in the Proceedings of the National Academy of Sciences on 13 January.

Read the full story at Seafood Source

Two groups studying how to make fisheries more climate-resilient

May 28, 2019 — With a growing consensus that climate change is causing drastic transformations of marine ecosystems and fish stock dynamics, two recent studies have addressed the importance of taking a more adaptive and responsive approach to their management.

The first study, published in the ICES Journal of Marine Science, shows that adjusting fishing levels when fish populations change is key to making global fisheries more climate-resilient. The result of making this shift would be healthier oceans and a more stable supply of fish for consumption, according to scientists at the Environmental Defense Fund and the University of California, Santa Barbara.

Their paper outlines the fact that many commercially important fish stocks are vulnerable to the effects of climate change, and that managing those stocks sustainably in the future will be a large and growing challenge for fisheries scientists and managers. The paper recommends responsive harvest control rules (HCRs) that automatically reduce catch percentages when decreases in biomass are detected, and increases when biomass increases. By adopting HCRs, “inherent resilience” could be introduced into the system, reducing the adverse effects of climate change while longer-term solutions are sought to better address the negative impacts of global warming.

“Using the right harvest-control rule is like having adaptive cruise control for your fishery,” said Jake Kritzer, a senior director of Environmental Defense Fund’s Oceans program and lead author of the paper. “When you need to slow down, the system can automatically adjust to the right level. Then, when the road ahead is clear, it allows you to return to a higher level.”

Warmer waters caused by climate change are resulting in lower reproduction rates in fish and forcing them to migrate out of their natural ranges. The current system for managing fish catches is often not adaptive enough to respond to these dynamics, the report noted. In addition, current catch levels are being calculated on biomass that may be incorrect as a result of these large-scale changes, the report found.

Read the full story at Seafood Source

ALASKA: Study pinpoints trend toward fisheries specialization

May 10, 2019 — Commercial fishermen in Alaska have gotten older in the past three decades. As it turns out, they’ve become more specialized, too.

Fewer permits overall are in the water; between the early 1990s and 2014, commercial fishing permits in Alaska decreased by 25 percent. On top of that, fewer individual fishermen are moving between fisheries.

From 1988-2014, the number of individuals holding multiple permits declined from 30 percent to 20 percent, according to a study published in the journal Fish and Fisheries.

The bottom line: fishermen are increasingly putting all their economic eggs into one basket, and that makes them more vulnerable to the ups and downs of fishing.

The study was born out of a workgroup that met through the National Center for Ecological Analysis and Synthesis at the University of California Santa Barbara, said co-author Anne Beaudreau, an associate professor of fisheries at the University of Alaska Fairbanks.

The original intent was to study the long-term effects of the 1989 Exxon Valdez oil spill, but the data on fisheries specialization arose out of that work, she said.

“As we worked on this, we realized there are so many things that have caused long-term changes in the Gulf of Alaska; in the fisheries, it’s really hard to see the long-term effects of the oil spill,” she said. “A lot of the focus of the working group was on the biological effects … this paper sort of came out of the end of that.”

Read the full story at the Alaska Journal of Commerce

First ever high-seas conservation treaty would protect life in international waters

April 4, 2019 — No flag can claim the high seas, but many nations exploit them. As a result, life in the two-thirds of the oceans beyond any country’s territorial waters faces many threats that are largely unregulated, including overfishing and the emerging deep-sea mining industry.

Now, nations are negotiating the first-ever high-seas conservation treaty, which the United Nations expects to finalize next year. As delegates met this week at U.N. headquarters in New York City to hash out the details, marine scientists moved to influence the outcome. One research group unveiled the results of a global mapping effort that envisions expansive new marine reserves to protect key high-seas ecosystems. Other teams are working on maps of their own using powerful modeling tools to weigh a reserve’s potential for achieving key conservation goals, such as protecting important feeding grounds or helping sea life adapt to warming seas, against its economic costs.

“The policy opportunity this represents is much rarer than once in a lifetime,” says marine ecologist Douglas McCauley of the University of California, Santa Barbara. Nations are asking “how we should protect two-thirds of the world’s oceans, [and] it’s the first time in human history that this has ever been asked.”

Read the full story at Science Magazine

Climate change is depleting our essential fisheries

February 28, 2019 — A new study published Thursday in the journal Science outlines the impacts warming waters are having on commercially important fish species.

The world’s fishing industry relies on what’s called fisheries, the clusters of regional fish populations that people can catch economically. And on average, the researchers found that the numbers of fish in critical fisheries around the world have decreased by four percent since 1930.

Fisheries located in the Sea of Japan and the North Sea were the worst off. They experienced as much as a 35 percent drop in their numbers. Other fisheries, however, benefitted from warmer waters, and their populations grew, an expansion scientists warn could create unsustainable competition for resources.

“We were surprised at the strength the impact of warming has already had on fish populations,” says the study’s lead author, ecologist Chris Free at the University of California Santa Barbara.

Read the full story at National Geographic

Global fisheries could still become more profitable despite global warming

August 30, 2018 — Researchers from Japan’s Hokkaido University, the University of California, Santa Barbara (UCSB), National Center for Ecological Analysis and Synthesis, and Environmental Defense Fund  (EDF) found that harvesting sustainable amounts of seafood globally over the next 75 years can lead to higher total food production and profits, even taking into consideration the fish populations which are projected to decline as the ocean warms and habitats change.

This is because, under what has been determined as the best management scenario, some major fish and shellfish stocks that are commercially harvested, broadly referred to as fisheries, will grow and become more profitable, offsetting the many others projected to shrink or even disappear. On a global average, profitability could rise by 14 billion USD and harvest by 217 million metric tons above today’s levels, according to the study.

There is a catch. In the model, the growth was achieved under the projected moderate warming of 2.2°C (3.9°F) above average global temperatures by 2100. But if temperatures rise further, global fish harvest and profits are expected to decline below today’s levels even with the best management in place.

The researchers say their study, published in Science Advances, conveys an important message: the oceans can continue to be a source of healthy seafood and sustainable livelihoods for billions of people, but only if action is taken to manage the stocks well and limit the carbon emissions that drive climate change.

Read the full story at Science Daily

Why Don’t Fish Swim Upside Down?

November 10, 2017 — There is no up or down in space, yet in shows like Star Trek, ships are always oriented the same way: right side up. It’s a scientifically unnecessary trope that has become a running joke among science fiction fans.

Yet here on Earth, fish find themselves in a strikingly similar situation. As a fish glides through its weightless, three-dimensional, watery world, it almost always stays right side up. The question—for both starships and fish—is why?

It’s an easier question to answer for fictional spaceships than real-life fish.

In movies or on television, directors show ships the way they do because it makes the scene more understandable to viewers, creatures accustomed to a gravity-bound world. “We have a fixed idea that everything should be right side up,” says Frank Fish, a functional morphologist at West Chester University in Pennsylvania. But what about fish? It’s a puzzle.

“I can’t get into the mind of a fish—despite my name—and determine why it would particularly do that,” says Fish.

Deepening the mystery is that scientists know few reasons why a fish would swim in any particular orientation—yet they clearly have a preference. Unlike land animals, fish don’t push against the ground to move. And, while moving, fish are no more streamlined in one orientation than another. What’s more, most fish are top heavy, says Brooke Flammang, who studies fish biomechanics at the New Jersey Institute of Technology. Like a child balancing on a beach ball in the pool, gravity wants them to flip. So why don’t they?

The leading explanation is that fish began life right side up, evolutionarily speaking, and so most never had a reason to change. “Just between us, yeah, they never bothered,” says Milton Love, a semi-retired marine zoologist at the University of California, Santa Barbara.

A fish’s preferred orientation “goes back to those very early steps of building a left side and a right side, a head end [and] a tail end,” says Peter Wainwright, who studies fish morphology and behavior at the University of California, Davis.

There are two groups of animals that have distinct left and right sides, Wainwright says. The first group, protostomia, includes most invertebrates, like insects and mollusks. Early on in development, as embryos, these animals develop a cavity that goes on to become the mouth.

Read the full story at Hakai Magazine