Alaska’s major commercial fisheries will likely face significant challenges due to climate change, with some species facing bleak futures and others poised to thrive due to warming water temperatures and rising ocean acidity, according to Terry Johnson, a professor of fisheries with the University of Alaska’s Sea Grant Marine Advisory Program.
Speaking on Friday, 17 November at the Pacific Marine Expo, Johnson said the biggest losers will be the crab and pollock fisheries, while flounder and halibut face a brighter future and the fate of salmon is mixed based on their spawning and migration habits.
“Pollock are confronting a grim future,” Johnson said. “If you comb through the literature, you’ll see a lot of things that indicate that if temperatures continue to increase, that will have downward effect on pollock in the Bering Sea.”
The king, Tanner and snow crab fisheries are also in for a “major hit,” Johnson said.
“Things do not look good for future of crab industry,” he said. “In general, they all respond to the same triggers and are probably in for a decline.”
The full impact of warming waters on fisheries in Alaska and the Bering Sea won’t be felt for another 30 to 40 years, Johnson said. But with average annual temperatures trending consistently up, and last year ranking as the warmest ever on record in the Bering Sea, wide-scale biological changes are likely, if not inevitable, Johnson said.
Overall, that news is not necessarily bad from a purely commercial perspective, Johnson said.
“Projections that have been done suggest that in high latitudes including Alaska, biological production is going to increase dramatically. If that’s the case, that’s probably going to be a good thing for fishermen,” he said.
Halibut seem to respond well to higher temperatures and may be entering a period of higher production, and salmon might be able to move into new grounds in the Arctic that “may eventually be large enough to support a commercial fishery,” Johnson said. However, existing populations of sockeye, chinook and coho salmon may be disturbed, and could decline.
So far, according to Johnson, there haven’t yet been significant consequences from long-term climate change documented in Alaskan fisheries. And Johnson told his audience shouldn’t take his predictions as gospel.
“Making predictions is difficult when so many variables remain unknown,” Johnson said.
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