November 19, 2019 — Norton Sound red king crab are moving, Arctic cod numbers have dropped significantly and Pacific cod are continuing to increase as the Northern Bering Sea ecosystem undergoes drastic change. That’s all according to preliminary results from a National Oceanic and Atmospheric Administration trawl survey this summer in the Northern Bering Sea (NBS).
Before Lyle Britt even began leading the NOAA Fisheries’ study of the NBS in September, he anticipated seeing more warm water fish in a region that stretches from Nunivak Island north to the Bering Strait.
“We can tell that the ecosystem is very much in flux up here,” Britt said. “We’re seeing expansion of ranges of some fish and invertebrates, and we’re seeing the retraction of others. Now how permanent or ephemeral those are, I think is still in question.”
As an example of a species that’s expanding its range based on what was discovered in the 2010 baseline survey of the Northern Bering Sea, Britt points to Pacific cod.
“Between 2010 and 2017 there was about a 900% increase in the amount of Pacific cod we saw in the Northern Bering Sea region, based on that biomass or total weight estimate,” he said. “That number sounds really dramatic in part because there were so few in 2010 and now there are some. That number increased between 2017 and 2019 by about 30%, so it’s continued to go up.”