Saving Seafood

Ocean heat waves like the Pacific’s deadly ‘Blob’ could become the new normal

February 1, 2019 — When marine biologist Steve Barbeaux first saw the data in late 2017, he thought it was the result of a computer glitch. How else could more than 100 million Pacific cod suddenly vanish from the waters off of southern Alaska?

Within hours, however, Barbeaux’s colleagues at the National Oceanic and Atmospheric Administration (NOAA) in Seattle, Washington, had confirmed the numbers. No glitch. The data, collected by research trawlers, indicated cod numbers had plunged by 70% in 2 years, essentially erasing a fishery worth $100 million annually. There was no evidence that the fish had simply moved elsewhere. And as the vast scale of the disappearance became clear, a prime suspect emerged: “The Blob.”

In late 2013, a huge patch of unusually warm ocean water, roughly one-third the size of the contiguous United States, formed in the Gulf of Alaska and began to spread. A few months later, Nick Bond, a climate scientist at the University of Washington in Seattle, dubbed it The Blob. The name, with its echo of a 1958 horror film about an alien life form that keeps growing as it consumes everything in its path, quickly caught on. By the summer of 2015, The Blob had more than doubled in size, stretching across more than 4 million square kilometers of ocean, from Mexico’s Baja California Peninsula to Alaska’s Aleutian Islands. Water temperatures reached 2.5°C above normal in many places.

Read the full story at Science Magazine

Climate change preview? Pacific Ocean ‘blob’ appears to take toll on Alaska cod

November 4, 2017 — Gulf of Alaska cod populations appear to have nose-dived, a collapse fishery scientists believe is linked to warm water temperatures known as “the blob” that peaked in 2015.

The decline is expected to substantially reduce the Gulf cod harvests that in recent years have been worth — before processing — more than $50 million to Northwest and Alaska fishermen who catch them with nets, pot traps and baited hooks set along the sea bottom.

The blob also could foreshadow the effects of climate change on the marine ecosystem off Alaska’s coast, where chilly waters rich with food sustain North America’s richest fisheries.

Federal fisheries biologist Steve Barbeaux says that the warm water, which has spread to depths of more than 1,000 feet, hit the cod like a kind of double-whammy. Higher temperatures sped up the rate at which young cod burned calories while reducing the food available for the cod to consume.

“They get weak and die or get eaten by something else,” said Barbeaux, who in October presented preliminary survey findings to scientists and industry officials at an Anchorage meeting of the North Pacific Fishery Management Council. The 2017 trawl net survey found the lowest numbers of cod on record, more than 70 percent lower than the survey found two years earlier.

Barbeaux said the cod decline likely resulted from the blob, a huge influx of warm Pacific Ocean water that stretched — during its 2015 peak — from the Gulf of Alaska to California’s offshore waters.

Biologists tracked increases in bird die-offs, whale strandings and other events such as toxic algae blooms. Even today, its effects appear to linger, such as in the dismal survey results for salmon this past summer off Oregon and Washington.

Read the full story at the Seattle Times

Survey shows GOA cod biomass down 71 percent

October 16, 2017 — CORDOVA, Alaska — Surveys and preliminary modeling for the 2018 Pacific cod stock assessment show that Pacific cod biomass is down substantially in the Gulf of Alaska, a NOAA Fisheries research biologist told the North Pacific Fishery Management Council during its fall meeting in Anchorage.

The data for the report by Steve Barbeaux of the Alaska Fisheries Science Center in Seattle only became available several days before the council meeting and the council’s Scientific and Statistical Committee expressed its appreciation of the rapid and extensive investigation that Barbeaux and others made, the SSC said.

The most salient survey result was a 71 percent reduction in the Gulf of Alaska bottom trawl survey Pacific cod biomass estimate from 2015 to 2017, a drop observed across the Gulf and particularly pronounced in the Central Gulf, Barbeaux told the SSC.

Barbeaux also presented additional data sets to the SSC that appeared to corroborate the trawl survey results, including a 53 percent drop in the National Martine Fisheries Service 2017 longline survey, and low estimates in recent years by the Alaska Department of Fish and Game large mesh trawl survey. Barbeaux said Pacific cod fishery data from 2017 indicated slower rates of catch accumulation and lower catch per unit effort over the season, at least in the central Gulf, compared to other recent years, and a change in depth distribution toward deeper waters.

Read the full story at The Cordova Times

Decades of trawl surveys help Bering Sea climate change research

May 9, 2017 — There’s a new tool to help scientists and others interested in monitoring how Bering Sea fisheries respond to a changing climate.

Biologist Steve Barbeaux of the Alaska Fisheries Science Center has created hundreds of graphics mapping where 22 species of fish spend their time during different life stages.

The data comes from annual trawl surveys dating back to 1984, but Barbeaux says that information was hard to analyze as a whole.

“To understand the true impacts of climate change we have to look across all of these life stages to get a true picture of what’s going on,” Barbeaux said. “It potentially could be beneficial at one stage of life, but harmful at another stage of it’s life.”

Barbeaux started small — looking at greenland turbot, a species that is greatly impacted by temperature changes. When the fish develop from larvae to juveniles, they depend on a cold pool in the Bering Sea. But without it:

“You get high natural mortality,” Barbeaux said. “So for [the greenland turbot] the impact really is at that settlement stage. Versus pollock where that impact has more potentially to do with their midlife stage.”

Read the full story at KTOO

Study tracks 34 years of Bering Sea fish populations

April 24, 2017 — A newly released study from the Alaska Fisheries Science Center tracks distribution shifts of groundfish in the Eastern Bering Sea from 1982 to 2015.

Researchers say the visualizations provided by this 331-page document will help them to understand the life histories of 22 groundfish and skate species over time and space and provide clues to how climate change may potentially impact those species at different life stages.

During the standardized bottom trawl surveys of the Eastern Bering Sea shelf area between 20 and 200 meters from May to August in those years, researchers collected species composition and bottom temperature for all tows, as well as measurements from all fish encountered. That data provides a unique look at the spatial and environmental preferences of many species, as well as ontogenetic shifts in spatial distribution and environmental preferences over 34 years, they said.

Steve Barbeaux, the fisheries biologist who served as lead author of the study, said climate variability has increased in the Bering Sea in recent years and AFSC will use this information to study how ecosystems respond to change.

Read the full story at The Cordova Times