Climate change sends many fish species north

Pacific rockfishes found to be among most affected

A new study by researchers at Rutgers University says climate change is forcing hundreds of ocean fish and invertebrate species, including Pacific rockfishes, through the end of this century.

That study, of change already in progress, covers the North American continental shelfs on the Pacific and Atlantic coasts, according to Jim Morley, lead author, and Malin Pinsky, a co-author, of the article published on May 14 in the online journal PLOS ONE.

Species surveyed include finfish, sharks and rays, crustaceans and squid, with Pacific rockfishes, Atlantic cod and black sea bass found to be among those most affected.

The issue, in a nutshell, is that fish are sensitive to water temperatures, and as the water warms, whole populations of fish often shift to another area where water temperature is right for them, they wrote in the article.

“Climate change to shift many fish species north disrupting fisheries,” they wrote.

Their research draws in part on bottom trawl surveys of the Gulf of Alaska, Eastern Bering Sea and Aleutian Islands conducted from 1983 through 2014 by NOAA’s Alaska Fisheries Science Center. The article also cites sediment data sources from those areas.

The researchers found that as climate change continues and oceans warm, more species of fish will move north to where the temperature range is habitable for them.

The study notes that species from the United States and Canadian west coast, including the Gulf of Alaska, had the highest projected magnitude shifts in distribution, and many species shifted more than 1,000 kilometers under the high greenhouse gas emissions scenario. Following a strong mitigation scenario consistent with the Paris Agreement would likely produce substantially smaller shifts and less disruption to marine management efforts, the study said.

The central aim of the Paris Agreement is to strengthen the global response to the threat of climate change by keeping a global temperature rise this century well below 2 degrees Celsius above pre-industrial levels and to pursue efforts to limit the temperature increase even further to 1.5 degrees Celsius.

“We’ve already seen that shifts of a couple of hundred miles in a species’ range can disrupt fisheries,” said Morley, a former postdoctoral researcher at Rutgers-New Brunswick. “This study shows that such dislocations will happen all over the continent and on both coasts throughout the 21st century.”

“For commercial fishers, this often means longer trips and higher fuel costs,” said Pinsky, a professor of ecology, evolution and natural resources at the Rutgers-New Brunswick School of Environmental and Biological Sciences. “Some species along the U.S. and Canadian Pacific coasts will move as much as 900 miles north from their current habitats.”

Researchers used 16 different climate models, each with both a low level of greenhouse gas emissions and a high level, to develop projections for future ocean temperatures around North America.

Those lower-level emissions scenarios were in line with goals set by the Paris Accords, which President Trump withdrew the United States from earlier this year. Those projections were combined with statistical models of species temperature preference, which were based on bottom-trawl survey data from around the continent.

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