Saving Seafood

Size of Alaska’s Western Aleutian Island Passes Larger than Previously Thought

December 15, 2020 — The following was released by NOAA Fisheries:

There are thousands of small islands that comprise Alaska’s Aleutian Island chain, but only a few dozen significant passes among those islands. These passes are important bottlenecks for water exchange among the North Pacific, Gulf of Alaska, and the Bering Sea. However, until now there has been limited detail on estimates of pass location, size, shape, length, and depth.

“Flow estimates have been based on rough pass size estimates from over 50 years ago,” said Mark Zimmermann, fisheries biologist from the Alaska Fisheries Science Center. “We have updated information for eastern, western and central passes along the Aleutian Island chain. This new information will help oceanographers and ecologists better quantify impacts of water flow on Alaska marine ecosystems and better understand environmental and ecological changes that are taking place.”

Two new NOAA Fisheries’ studies provide more detail on the size and extent of the passes and the shoreline around the Aleutian Islands.

One study showed that all of the western-most Aleutian passes, from Kavalga to Semichi, are larger (18 to 71 percent) than previously reported. The last study was conducted for this area in the 1960s. This includes Amchitka Pass (+23 percent), the largest in the Aleutians.

The other study focused on the easternmost pass, False Pass, which posed a particular challenge for co-author Zimmermann. False Pass is unusual: it’s the only Aleutian pass that directly connects the shallow shelves of the western Gulf of Alaska and eastern Bering Sea. It is also the only pass with constricted southern and northern openings. We found this pass to have a single northern inlet to the Bering Sea—however, until recently it had two. This conflicts with current navigational charts, depicting two inlets to the Bering Sea now, compared to just one on the older charts (1926–1943).

“Our analysis of eastern pass sizes compared to the results of the 1960s study generated mixed results,” said Zimmermann. “In some cases, our pass size estimates were larger while in other cases they were smaller than previous estimates.”

In 2005, NOAA scientists updated information on some of the eastern and central passes. When Zimmermann looked at the two eastern passes from that study, he found that they were actually larger than previously thought. He also found that five central Aleutian passes were smaller than reported. The earlier study did not examine western pass sizes. The new studies include much more detailed information about the seafloor and shoreline that was not available at the time of the earlier analyses. As a result, they will be a great new resource for oceanographers and ecologists studying marine systems.

Read the full release here

Russian and American Scientists say warming water is pushing Bering Sea pollock into new territory

November 20, 2020 — In a new study, scientists have linked warming Arctic temperatures, changing wind patterns and shifting currents to movement of commercially valuable Alaska pollock in the Bering Sea.

The Bering Sea has seen the loss of a summer cold water barrier in recent years, which used to keep pollock from spreading out and moving north.

But while scientists are seeing drastic shifts in pollock movement patterns, further research needs to be conducted to know what the changes mean for communities like Unalaska and Dutch Harbor and the billion-dollar pollock industry.

“This research is really critical because pollock are a key ecological component of the Bering Sea shelf food web supporting the largest commercial fishery in the U.S. by biomass,” said Robert Foy, NOAA’s Alaska Fisheries Science Center director. “To get an accurate assessment of pollock abundance so that resource managers can set sustainable catch limits, we have to be able to understand pollock distribution, which certainly looks different under a warm water regime.”

Read the full story at KTOO

ALASKA: Seafood Bycatch Donation Relieves Hunger and Reduces Waste

November 2, 2020 — The following was released by NOAA Fisheries:

Fishermen sometimes unintentionally catch fish they do not want or cannot keep. This is called bycatch. While these fish are returned to the sea, many of them do not survive. This is a major problem worldwide—nearly 10 percent of global fishery catches are discarded each year

This waste of valuable seafood protein has been an increasing focus of management, industry, and public concern due to its ecological and economic impacts. That’s where our innovative donation program comes in.

Alaska fishermen occasionally catch Pacific halibut and salmon incidentally in trawls targeting groundfish. Because halibut and salmon are valuable targets of other fisheries, they are designated as prohibited species. Groundfish trawlers are not allowed to retain or sell them. Historically, all prohibited species caught in Alaska were discarded at sea to avoid any incentive to catch these species.

The North Pacific Fishery Management Council and the Alaska seafood industry have a long history of cooperative efforts to reduce bycatch. However, even after bycatch has been eliminated to the extent practicable, some is inevitable.

In 1996, NOAA Fisheries and the North Pacific Fishery Management Council established the Prohibited Species Donation Program. It takes a unique approach to the problem of discarded fish by making it possible for fishermen to donate some bycatch to hunger relief organizations. It simultaneously reduces waste, provides high quality seafood protein to people in need, and avoids incentives to catch prohibited species.

“Bycatch donation is an example of thinking outside the box. When we think about reducing waste, it is usually about avoiding bycatch. This program is a creative solution to maximize the value of the bycatch that can’t be avoided,”  said Jordan Watson, NOAA Fisheries biologist at the Alaska Fisheries Science Center.

Read the full release here

Wind Influences Pollock Success in the Gulf of Alaska

September 29, 2020 — The following was released by NOAA Fisheries:

For young Alaska pollock in the Gulf of Alaska, survival may depend on which way the wind blows.

A study conclusively shows for the first time that year-to-year variation in the geographic distribution of juvenile pollock in the Gulf of Alaska is driven by wind. Depending on wind direction, water movement may retain juvenile fish in favorable nursery habitats, or transport them away. Young fish that are transported to less favorable habitats are less likely to contribute to year-class strength— the abundance of adults available to the valuable Gulf of Alaska pollock fishery.

For NOAA Fisheries biologist Matt Wilson of the Alaska Fisheries Science Center, the new study addressed a longstanding question.

“When we began this research, scientists thought that lots of juvenile fish would mean a relatively strong adult year-class. But in some years our surveys found a lot of juvenile pollock, followed by a weak year class. In other years a high number of juveniles grew into a strong year class,” Wilson said. “We undertook this research to better understand why large numbers of juveniles do not always translate into a high abundance of adults.”

Wilson and co-author Ned Laman also observed that the geographic distribution of juveniles was highly variable from year to year. In some summers, a very large proportion of the juvenile population was far southwest of the main spawning grounds.

“In this study we asked: what is the cause and consequence of year-to-year geographic variability in the distribution of juvenile pollock in the Gulf of Alaska?” Wilson said.

Read the full release here

Pink Salmon May Benefit as Pacific Arctic Warms

September 1, 2020 — The following was released by NOAA Fisheries:

The Pacific Arctic is undergoing a rapid transformation. As temperatures rise and sea ice melts, some species will do better than others. A new study suggests that pink salmon may be one of those species.

“Our results suggest that warming is both increasing freshwater habitat and improving early marine survival of pink salmon in the northern Bering Sea,” said Ed Farley, NOAA Fisheries biologist at the Alaska Fisheries Science Center, who led the study.

The study provides insight into the response of pink salmon to climate change. The findings are valuable information for commercial and subsistence fisheries, and fishing communities, preparing for future changes.

“Subsistence harvesters would like to know what foods may be available to them now and into the future,” Farley said.

“The importance of fish in Arctic subsistence economies cannot be overstated; they are some of the most commonly eaten foods,” said coauthor Todd Sformo, biologist at the North Slope Borough Department of Wildlife Management.

“In the past on the North Slope, salmon have been used for dog food and even considered nuisance fish when interfering with preferred species such as aanaakliq or broad whitefish in the inland rivers. Recently, there seems to be a change both qualitatively and quantitatively in the use of salmon as a main dish and for smoking.

“Participating in this study allowed me to present a subsistence perspective, learn how fellow researchers measure production dynamics, and better understand how pink salmon are responding to climate warming in the northern Bering Sea. While this research is further south than the waters surrounding the North Slope, it is a beginning of our attempt to account for potential change in subsistence fishing.”

Read the full release here

Fishing Families and Women in Alaska’s Fisheries

August 24, 2020 — The following was released by NOAA Fisheries:

Over recent decades, Alaska’s fisheries have undergone many regulatory, environmental, social, and economic changes, which have differentially affected dynamics in fishing families. Researchers from the Alaska Fisheries Science Center explored these changes and their effects on fishing families in a series of focus groups held throughout Gulf of Alaska fishing communities in 2017 and 2018. These focus groups covered three topics examining family roles and gender division of labor; impacts of management, environmental, economic and social conditions on these roles; and, the future of fishing families and women in Alaska’s fisheries. The research demonstrates the integral work of women in fishing families and their dynamic roles in Alaska’s fisheries more broadly. It further showcases how fishing families have, and continue to, adapt to multifaceted conditions in Alaska’s fisheries. This research has resulted in several scientific journal publications and web stories (which are available below), and is an ongoing effort to document novel conditions, adaptations, and resilience.

Thanks to Sarah Marrinan, North Pacific Fishery Management Council staff, for help with conducting these focus groups.

Read the full release here

Near-Infrared Technology Identifies Fish Species from Otoliths

July 7, 2020 — The following was released by NOAA Fisheries:

Aim a beam of near-infrared light at an otolith, and it reflects a literal spectrum of information on the biological and environmental history of a fish.

NOAA Fisheries scientists are developing ways to use near-infrared spectroscopy (NIRS) analysis of otoliths (fish ear stones) to provide accurate information for sustainable fisheries management faster. NIRS has already proven its value as a time- and cost-effective method to determine the age of fish.

Now, for the first time, scientists have used NIRS analysis of otoliths to identify fish species and populations. The new technique successfully differentiated 13 marine fish species from four large marine ecosystems around the country.

“Our study shows the potential of NIRS as a fast and reliable method of identifying fish species and populations,” said Irina Benson, Alaska Fisheries Science Center biologist. She led the study with Age and Growth Program colleague Thomas Helser and Beverly Barnett of the Southeast Fisheries Science Center. “This technology could provide information for stock assessment and management faster than traditional methods. It expands the possibilities for collecting data to support ecological studies. It is a big step forward for NOAA Fisheries’ strategic initiative to develop NIRS technology for fisheries science.” 

Read the full release here

Study: Marine heat waves will decimate fish at twice the rate climatologists previously predicted

June 9, 2020 — Over the last decade, two massive marine heatwaves, better known as “blobs” swept the North Pacific Ocean, raising surface temperatures more than 5 degrees Fahrenheit causing blooms of toxic algae and major die-offs in the ecosystem. A new study from the University of British Columbia reports that as these heatwaves continue, they may have far more devastating implications to fisheries than previously predicted.

Climate scientists have known for years that global warming would have devastating long-term impacts on marine species. Already, fast-melting Bering Sea ice is threatening spotted seals and other marine mammals. Warming Gulf of Alaska waters wiped out cod eggs in 2019, causing a crash in cod stocks. Record warm waters in the Yukon River last summer killed thousands of migrating salmon with heat stress.

While climate change is steadily warming oceans all over the world, marine heatwaves, like the two North Pacific “Blobs,” are causing more dramatic swings in surface temperatures. In 2014 and again in 2019, ocean temperatures in Alaska rose as much as 5 degrees Fahrenheit.

Read the full story at Alaska Public Media

Autonomous Vehicles Help Scientists Estimate Fish Abundance While Protecting Human Health and Safety

June 2, 2020 — The following was released by NOAA Fisheries:

Scientists are capitalizing on existing technological capabilities and partnerships to collect fisheries data. This will help fill the information gap resulting from the cancellation of FY20 ship-based surveys due to the COVID-19 pandemic. NOAA Fisheries plans to use autonomous surface vehicles to collect some critically needed data to support management of the nation’s largest commercial fishery for Alaska pollock.

“Extraordinary times require extraordinary measures,” said Alex De Robertis, NOAA Fisheries fisheries biologist and project lead for the Alaska Fisheries Science Center. “We knew there was a possibility that surveys may be cancelled this year, so we worked on a contingency plan to collect some data just in case. We were able to capitalize on our previous experience working closely with Saildrone and NOAA Research’s Pacific Marine Environmental Laboratory to get things off the ground quickly.”

This effort supports NOAA’s broader strategy to expand the use of emerging science and technologies including unmanned systems, artificial intelligence, and ‘omics to advance ocean research. NOAA released its strategy in February.

“The Alaska Fisheries Science Center has been engaged in research and development efforts to test new technologies to both improve our operating efficiencies and enable us to quickly respond when situations like this arise,” said Robert Foy, Alaska Fisheries Science Center Director. “Providing the best available science to support management decisions is at the heart of our mission to ensure the health of marine ecosystems while supporting sustainable commercial and recreational fisheries and strong local economies.”

Read the full release here

New Modeling Approach Provides Valuable Insights into the Important and Complex Role of Environmental Variables in Juvenile Fish Survival

May 29, 2020 — The following was released by NOAA Fisheries:

Variation in the productivity and sustainability of fish resources is determined, in part, by large changes in juvenile fish production from year to year. This is defined as “recruitment.” Fisheries oceanographers and fish stock assessment scientists have been trying to better understand and predict this variation for more than 100 years.

“We are seeing a lot of changes in the Bering Sea ecosystem. With analytical tools like this, we should be able to quickly identify factors affecting juvenile fish survival in a given year to generate reliable estimates of future productivity. This may help resource managers to more effectively target their management efforts,” said Jim Thorson, Habitat Ecological Processes Research Program Lead, Alaska Fisheries Science Center and lead author for the paper.

For the first time, scientists glimpsed how ocean temperature in different parts of Alaska’s Bering Sea may have influenced juvenile fish survival over the past three decades. They also gained valuable insights into how it may be affected under warmer ocean conditions in the future.

This unique approach combines oceanographic data collected from research surveys (1982-2018) with recruitment data into a single model. It also incorporated end-of-century projections of bottom and sea surface temperatures for the eastern Bering Sea. Scientists then used global climate models to develop regional-scale projections.

The authors see this an important step to understand the complex relationship between fish stock production and long-term climate processes. The ongoing collection of biological and environmental data will help to further improve these predictions.

Read the full release here