Saving Seafood

Researchers try to understand why Pacific cod stocks are crashing in Gulf of Alaska

May 31, 2018 — On an island about 4 miles off of Kodiak, marine scientists working with the University of Alaska are trying to figure out why Pacific cod stocks are crashing in the Gulf of Alaska.

And, how climate change may be affecting the fish when they’re young.

Mike Litzow and, his wife, Alisa Abookire, try to pull in a beach seine on a soggy gray day on Long Island. But, they catch more seaweed than fish as they slowly sink deeper into the shore’s mud.

“We have to get some kelp out, Liz,” Litzow said. “Oh no, it’s the freaking motherload. This will be our day right here if we aren’t careful.”

This isn’t a normal fishing trip.

The marine scientists are collaborating on a study for the University of Alaska Fairbanks to figure out why Pacific cod stocks are declining in the Gulf of Alaska and how warming waters may be affecting the species when they’re young.

Read the full story at KTOO 

 

Why are Pacific Cod Stocks Crashing?

February 13, 2018 — “The status of Pacific cod is probably the biggest fishery issue facing Kodiak right now, with the quota cut 80 percent for 2018,” said Mike Litzow, a University of Alaska Fairbanks associate professor at the Kodiak Seafood and Marine Science Center.

Pacific cod stocks have collapsed, possibly because recruitment (production of young fish to enter the population) has been very low during a recent string of incredibly warm years in the Gulf of Alaska, he said.

Scientists don’t know why cod stocks are shrinking. The leading hypothesis is that warmer temperatures increase the metabolic rates of young cod, and their food sources don’t supply enough energy.

There’s a sticking point—there’s not enough data to test the theory. Studies of fish ecology and population dynamics in Alaska are overwhelmingly conducted in the summer. Almost nothing is known about wintertime ecology of juvenile Pacific cod.

To help provide answers, Litzow and fisheries oceanographer Alisa Abookire embarked on a pilot study this month to collect information about habitat use, diet and energetics of juvenile cod.

They are sampling the fish with a beach seine and taking ocean water data aboard a semi-enclosed 22 foot skiff. To stay warm they wear insulated paddling suits.

Litzow and Abookire are collaborating with scientists at the Hatfield Marine Science Center in Newport, Ore., who have been studying juvenile cod in Kodiak over the last 12 years. The pilot study is funded by the Ocean Phoenix Fund through the University of Alaska Foundation.

Read the full story at Alaska Native News