Saving Seafood

Ocean currents vital for distributing heat could collapse by midcentury, study says

July 27, 2023 — A system of ocean currents that transports heat northward across the North Atlantic could collapse by mid-century, according to a new study, and scientists have said before that such a collapse could cause catastrophic sea-level rise and extreme weather across the globe.

In recent decades, researchers have both raised and downplayed the specter of Atlantic current collapse. It even prompted a movie that strayed far from the science. Two years ago the United Nations Intergovernmental Panel on Climate Change said any such catastrophe is unlikely this century. But the new study published in Nature Communications suggests it might not be as far away and unlikely as mainstream science says.

The Atlantic meridional overturning circulation is a vital system of ocean currents that circulates water throughout the Atlantic Ocean, according to the National Oceanic and Atmospheric Administration. It’s a lengthy process, taking an estimated 1,000 years to complete, but has slowed even more since the mid-1900s.

Read the full article at the Associated Press

ALASKA: Why sockeye flourish and chinook fail in Alaska’s changing climate

July 27, 2023 — University of Washington ecologist Daniel Schindler is at the mouth of a salmon stream at Lake Nerka, in Southwest Alaska. It’s roiling with fish.

“They sort of pile up in balls of thousands of fish for a couple of weeks. I think that’s when they’re doing their final maturation,” he said of the sockeye mob. “They’re jostling with each other and splashing, occasionally jumping.”

Schindler is in his 27th year of field work, studying Bristol Bay sockeye. This year is on par with the sockeye abundance Bristol Bay has seen in the last decade, he said, which is far higher than the historical average.

The unlikely hero of this story of plenty: Climate change.

“We tend to think of climate warming is bad news for wild animals,” he said. “But for sockeye Bristol Bay warming has been good news.”

For other salmon, climate change is a villain.

Chinook – or king – salmon are in terrible decline all over the state, and especially dire on the Yukon River. Meanwhile, sockeye – or reds – are having another banner year in Bristol Bay, and everywhere.  Scientists say they don’t know exactly why one salmon species is doing so well while the other is in crisis, but some clues are coming into sharper focus.

One key difference, Schindler said, is what kind of river habit each species needs.

Sockeye use lakes as their nurseries. Since the 1980s the water in those lakes has warmed significantly. The warmth stimulates plankton to reproduce more, and young sockeye eat plankton. Fifty years ago, Schindler said, a lot of sockeye spent two years in Lake Nerka before heading out to sea.

“And now they grow so fast that nearly all of them leave after a single year in freshwater, which is a reflection of the fact that the freshwater systems have become more productive,” he said.

Read the full article at Alaska Public Media

Warmer ocean temperatures spawn California market squid boom

July 23, 2023 — U.S. West Coast fishers are enjoying a monumental season for California market squid.

A cool, wet beginning of the year has helped created ideal spawning conditions for the squid (Doryteuthis opalescens), which grow around eight to 10 inches and live six to nine months. With a geographic range stretching from Alaska to Mexico, California market squid spawn from April to November off the coast of California. Fishermen target the squid shortly after they spawn to ensure the health of the population. However, little is known about their population abundance as no study has ever been carried out by NOAA.

Read the full article at SeafoodSource

What climate change and extreme temperatures could mean for Bristol Bay salmon

July 19, 2023 — This summer is a colder, rainier, and buggier season in Bristol Bay, and across Alaska. Meanwhile, last week the world faced four straight days of the hottest temperatures on  record, marking Earth’s extreme warming.

The biggest challenge of climate change for Bristol Bay salmon isn’t necessarily warming temperatures right now. It is the variability, said Bill Templin, Chief Salmon Fisheries Scientist for Alaska Department of Fish and Game.

“You know, climate change isn’t just directional. It’s not just that things are warming, it’s also that there’s greater variability in the systems,” he said.

Templin believes these cold, wet, stormy summers are a product of climate change too.

“There can be a wider swing of hot and cold or dryness, drought, flooding, excessive water in the systems,” said Templin. “That variability makes it hard for an organism to adapt to the changes which can lead to reduced productivity from systems that are otherwise healthy, with healthy habitats and low fishing pressures.”

What does that mean for salmon?

There’s some good news. Starting in freshwater, where salmon return to spawn and remain the first year of life, Bristol Bay’s deep lakes provide a natural buffer to temperature changes.

“So it seems like the lakes are really this big buffering mechanism,” said fisheries ecologist and researcher Daniel Schindler with the University of Washington’s Alaska Salmon Program. That’s critical for the salmon’s success.

Freshwater lakes are deep and stratified, meaning temperatures of the water are warmer at the surface going down to cooler at the bottom. Salmon can dive deep and escape warmer surface temperatures. According to Schindler, that means they can return to spawn earlier if ocean temperatures are too warm, like the birth ward at the hospital.

Read the full article at KDLG

How Marine Heat Waves Affect the Ocean – And What Can Be Done

July 17, 2023 — On 4 July 2023, the World Meteorological Organization declared the beginning of an El Niño phase, a climate pattern that drives up temperatures across land and sea.

Past weather events provide clues about what extreme temperatures could mean for the ocean. For instance, in December 2010, a wave of unusually warm water swept across the luxuriant and biodiverse seagrass meadows of Australia’s Shark Bay. In a matter of days, it destroyed a third of the habitat, unthreading the delicate seagrass quilt and, over the next three years, releasing between 2 and 9 billion tonnes of carbon into the atmosphere. “The losses there were phenomenal,” says Kathryn Smith, a researcher with the UK’s Marine Biological Association.

Scientists call the event a “marine heatwave”, meaning a period of exceptionally high water temperature that starts suddenly and continues for days to months, distinguishing it from long-term warming trends. Like heatwaves on land that threaten terrestrial ecosystems, heatwaves at sea harm marine life, posing “a clear and present threat to the systems we depend on,” says Sarah Cooley, director of climate science at the Ocean Conservancy.

These impacts are expected to grow. The UN’s climate science body, the IPCC, projects that by 2100 marine heatwaves will be up to 50-fold more frequent, and 10-fold more intense compared to pre-industrial times. Scientists are now developing ways to forecast these events. Their research can feed into measures that mitigate the threats for vulnerable habitats, species, and the coastal communities that depend on them.

Read the full article at The Maritime Executive

Warmer Ocean Temperatures Increase Risk of Salmon Bycatch in Pacific Hake Fishery

July 17, 2023 — Rates of Chinook salmon bycatch in the Pacific hake fishery rise during years when ocean temperatures are warmer, a signal that climate change and increased frequency of marine heatwaves could lead to higher bycatch rates, new research indicates.

During years when sea surface temperatures were higher, including during a marine heatwave, Chinook salmon were more likely to overlap with the Pacific hake and raise the risk of bycatch as they sought refuge from higher temperatures.

The findings, based on 20 years of bycatch data and ocean temperature records, provide new insight into the ecological mechanisms that underlie bycatch, which is the incidental capture of a non-targeted species, said the study’s lead author, Megan Sabal.

“The impact of ocean warming on bycatch has potential cultural, economic and ecological consequences, as the hake and salmon fisheries are each worth millions of dollars and salmon are critical to both Indigenous tribes’ cultural heritage and healthy ecosystems,” said Sabal, who worked on the project as a postdoctoral scholar at Oregon State University.

Pacific hake, also known as Pacific whiting, is the largest commercial fishery by tonnage on the U.S. West Coast. The rate is low, but bycatch remains a concern for the Chinook salmon population, said Michael Banks, a marine fisheries genomics, conservation and behavior professor at Oregon State University and a co-author of the study.

Read the full article at ECO Magazine

New experiment to test whether ocean warming opens a pathway for sea turtle

July 13, 2023 — Every now and then, small groups of endangered North Pacific loggerhead turtle hatchlings swim from Japan to the coastal waters of Baja Mexico and California, a journey of nearly 8,000 miles that has mystified scientists for decades.

The crux of the mystery is not how loggerheads find their way: Scientists believe they navigate the globe using Earth’s magnetic fields, as do salmon, elephant seals, some species of shark, and other turtle species. Rather, experts have puzzled over how these young, tropical, temperature-sensitive turtles manage to cross a deep-ocean zone that’s cold enough to be nearly impassable for most creatures.

“They go past the point of no return and head toward Baja, when most of the other turtles turn back,” said Stanford marine ecologist Larry Crowder. Now, an international team of scientists has released from a ship on the high seas 25 satellite-tagged turtles in an experiment that could confirm or modify the leading explanation for how they do it. Three more cohorts are planned for release over the next four years, for a total of 100 tagged turtles.

Pacific Ocean Deep-Sea Mining Could Threaten Tuna ‘Climate Refuge’

July 12, 2023 — A new study has found that deep-sea mining may pose a big threat to tuna species moving into the eastern Pacific Ocean as climate change pushes them into the open ocean.

Dr Diva Amon, a scientific researcher at the Benioff Ocean Science Laboratory at the University of California, Santa Barbara and Director and Founder of NGO SpeSeas explains that climate pressures are expected to push bigeye, skipjack and yellowfin tuna from their current range near small, developing Pacific nations into a “climate refuge” in a deep-ocean zone of the eastern Pacific Ocean.

“These tuna are going to be leaving these Pacific Nations and moving into the high seas and progressively eastward,” she says, adding that the highly-mobile tuna might arrive to these new areas only to find it is already inhospitable due to deep-sea mining.

Read the full article at Forbes

MASSACHUSSETTS: Technology, marketing among 20 Massachusetts grants for $1.6 million

July 9, 2023 — Massachusetts state officials announced $1.6 million in grants will go to 20 businesses and organizations “to support innovative approaches to enhance Massachusetts commercial marine fisheries and the seafood industry.”

“Massachusetts is a leader in protecting the health of our fishing industry, and this funding shows our commitment to keep the industry thriving by utilizing cutting-edge technology and the latest scientific research,” Gov. Maura Healey said in announcing the grants June 30. “Our administration is taking a holistic approach to combating climate change, which includes supporting our fisheries, advancing green energy, and enhancing the state’s blue economy.”

The funding is coming through the Environmental Economic Innovation and Resiliency in Marine Fisheries Grant Program, supplemented by the American Rescue Plan Act (ARPA). The goal is encouraging projects “that work to mitigate economic barriers resulting from climate change and promote sustainable, local fisheries development in Massachusetts,” according to the state Division of Marine Fisheries.

 “The fishing industry is on the front lines of climate change, and it’s critical we make meaningful, long-term investments now to ensure the sustainability and resiliency of our marine fisheries,” Rebecca Tepper, the state energy and environmental affairs secretary. “This funding is two-fold in that we are helping fishers and their families recover from the pandemic while supporting new approaches that will safeguard our valuable marine resources from climate harm.”

Read the full article at the National Fisherman