Black cod bycatch in the Bering Sea surges

Trawlers in the Bering Sea have hauled up some 2,500 metric tons of black cod in bycatch circa the end of last month, according to a NOAA fisheries report.

An Alaska Public Media report suggests that small-boat fishermen who have bought black cod (also known as sablefish) fishing rights are frustrated that there will be fewer fish to harvest after the accidental catch of the trawlers.

The 2,500 metric tons harvested this year is more than ten times the amount caught in 2016.

“You can’t catch these fish twice,” said small-boat fisherman Bob Alverson. “So if they die out there, they’re not likely to have a chance at migrating back.” 

Trawlers trying to catch lower value fish such as pollock say that they haven’t changed their fishing practices.

“We try and go shallow to avoid them and they’re shallow. We try to go deep – I knew one guy who went to over 200 fathoms fishing for pollock, and he still got sablefish. It’s very hard to try and avoid them,” said trawl industry representative Brent Paine at an Alaskan fishery manager meeting last week. “This is really uncharted waters. We never even dreamed that sablefish would be an incidental catch problem.”

Others say that the bycatch is just a drop in the ocean. Black cod expert and fisheries scientist Dana Hanselman estimates that the bycatch is under one percent of sablefish between two and five years old.

Some anglers and scientists are attributing the boom in the black cod fishery to warming waters off the coast of Alaska.

“They’re a long-lived species, and that allows them to span across poor and favorable environmental conditions. What we’re seeing now, perhaps, is that sablefish are one of the winners of this marine heatwave that we’re kind of seeing,” said Hanselman. However, he did caution that it’s still early to draw conclusion about why the fish is so prevalent.

“It’s just an interesting thing we’re observing at the moment and saying, ‘Wow, this really seems to correspond with this high heat wave,” Hanselman added.

Photo courtesy of Photomatz/Shutterstock