Heat Wave Massively Kills Marine Wildlife

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In the Pacific Northwest, dead mussels and oysters cover the rocks, their shells opening as if they were boiled. Sea stars cooked to death. Sockeye salmon swam slowly in the overheating Washington River, prompting wildlife officials to move them to cooler areas.

Exceptional combination temperature and the drought hit Western United States and Canada It has killed hundreds of millions of marine animals in the past two weeks and continues to threaten unknown species in freshwater, according to a preliminary estimate and interviews with scientists.

“This feels like one of those post-apocalyptic movies,” said Christopher Harley, a marine biologist at the University of British Columbia who studies the effects of climate change on coastal marine ecosystems.

Dr. To calculate the death toll, Harley first observed how many blue mussels lived on a given shoreline, how much of the area was a good habitat for mussels, and how many of the mussels died. He estimated the losses of the mussels alone in the hundreds of millions. Factoring in mussel beds and other coastal creatures — mussels, hermit crabs and other crustaceans, various worms, small sea cucumbers — deaths easily exceeded a billion, he said.

Dr. Harley continues to examine the damage and plans to publish a series of articles.

Such extreme weather conditions will become more frequent and intense, scientists say, as climate change caused by humans using fossil fuels harms both animals and humans. Hundreds died last week heat wave Parked over the Pacific Northwest. A study by an international team of climate researchers discovered that it would be almost impossible For such extremes to happen without global warming.

Just before the heat wave, Dr. When Harley received the dazzling forecasts, she thought about how low the tide would be at noon, cooking the exposed mussels, sea stars, and mussels. When he went to the beach on one of the hottest days last week, the stench of decay hit him immediately. The scientist in him admitted that he was excited to see the real-life impact of something he had been working on for a long time.

But the mood quickly changed.

Dr. “The more I walked and saw, the more sobering it all got,” Harley said. “It just went on and on.”

Dead sea stars, often the most spectacular creatures in tide pools, hit him especially hard. But the obvious mass victims were the blue mussels, an ecologically important species that feeds on starfish and sea ducks and creates habitat for other animals.

Scientists are just starting to think about domino effects. One concern is whether sea ducks that feast on mussels in winter before migrating to summer breeding grounds in the Arctic will have enough food to survive the journey.

“It’s something we’re starting to think about, at least,” he said.

He noted that the species living in the tidal zones were resilient and the mussels on the shady north side of the rocks survived. But if these extreme heatwaves happen too often, the species won’t have time to recover.

As the heatwave over the Pacific Northwest eased, the sweltering temperatures remained in much of the West of the Americas. now, looks like another heat wave is forming, only worsening the ongoing drought.

This means biologists are monitoring river temperatures with alarm. Salmon make an extraordinary migration, often hundreds of kilometers, from inland rivers and lakes where they were born to the sea and then back again to spawn the next generation. The long-standing network of dams in the western states already makes the journey dangerous. Now, with climate change’s worsening heat waves and droughts, scientists say conditions look grim without the intense intervention that comes with its own risks.

“We’re in critical temperatures three weeks before the most serious warming occurs,” said Don Chapman, a retired fisheries biologist who specializes in salmon and steelhead trout, when speaking of conditions with four dams along the Snake River in Washington. long debated. “I think we’re headed for disaster.”

The state of salmon shows a broader threat to species of all kinds as climate change worsens. Many animals were already struggling to survive due to human activities degrading their habitats. Throw in extreme heat and drought and their chances of survival are reduced.

As an emergency measure, workers at the Idaho Fish and Game agency began catching a variety of endangered sockeye salmon in the Lower Granite dam, putting them on a truck and driving them to hatcheries as a temporary measure to decide what to do next. (Idaho game officials first tried transporting adult fish by truck during a heat wave in 2015. This was done for juvenile salmon in a variety of runs for a variety of reasons.)

Biologist Jonathan Ambrose of the National Oceanic and Atmospheric Administration in California’s central valley said he wished we could do something similar. The chinook salmon he observed spawned in the mountains, historically. But since the Shasta Dam was built more than a quarter of a century ago, they adapted by breeding right in front of the mammoth structure they couldn’t pass through. The critical issue this year is that the water there is expected to get too hot for the eggs and fry. Previous efforts to secure state or federal funding to get them through the dam have failed.

“We’re looking at a mortality rate maybe 90 percent, or even higher this year,” said Mr Ambrose.

Elsewhere in California, for the first time since the state built the Iron Gate Fish Farm on the Klamath River in 1962 to make up for lost spawning habitat, state biologists won’t release their young salmon into the wild because they’re likely to die. Instead, they spread a million young salmon among other hatcheries that can house them until conditions improve.

University of British Columbia marine biologist Dr. “I want to find the positives and there are some, but it’s pretty overwhelming right now,” Harley said. “Because if we get too depressed or too depressed, we won’t keep trying. And we have to keep trying.”

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