AD Main Menu

Laine Welch: Seeking clues to shrinking stocks, scientists eye crab diets

Laine Welch

Did you know that red king crabs are cannibals and eat their babies but blue king crabs do not? Or that deep-water golden king crabs along the Aleutian Islands are almost indestructible and appear to resist the effects of ocean acidification?

Those are just a few of the secrets being revealed at the nation's top king crab research lab in Kodiak. Scientists at the Near Island center handle the yearly Bering Sea king crab surveys and use samples to study their biology and breeding. They hope to find clues about why king crab stocks are not returning to Kodiak and why recruitment is so low and slow at Bristol Bay.

Right now the researchers are studying crab diets.

"Not much has been done on that because crabs eat everything. They shred it. So we are trying to identify it with genetic signatures. To find out what they are eating helps us understand what's out there," said Bob Foy, director of the NOAA/Kodiak lab. "It helps us understand if the environment is producing enough food to the bottom of the ocean. What they've found in the Bering Sea is that there are cycles. If we understand the production of the ocean ecosystem, it can help predict how well the crab stocks might do."

The researchers recently learned that while female king crab lay hundreds of thousands of eggs, their viability can vary extremely over time. Foy said that discovery has changed the way crab stocks are surveyed.

"Now we are taking a certain number of crabs and monitoring what their reproductive status is. Hopefully, that will allow us to predict changes in the future," Foy said.

The crab researchers also are trying to discover why red king crab stocks are not rebuilding in Bristol Bay.

"Is it production or predation? Are the juveniles being swept away? What is leading to this problem," Foy asked. "We know there is a brood stock in Bristol Bay but what is happening to all the progeny?"

He pointed out that it takes up to eight years for king crab to grow to adulthood.

"So you need not just one good year class but multiple year classes that then have to make it eight years before it's viable. So a lot has to go right."

Cash for coastal trash

Lack of funds has stalled plans for marine debris cleanup projects along Alaska's coastlines, especially the large amounts coming ashore from Japan's horrific tsunami two years ago. It's estimated nearly 2 million tons of who knows what is headed Alaska's way.

That hasn't daunted the coastal cleanup projects of Kodiak's Island Trails Network (ITN), which has expanded its "cash for trash" pilot program beyond setnetters to include anyone with a boat.

"If they return the debris to Kodiak, we pay 50 cents a pound; if they leave it at a cannery or a remote pick-up location, it's 30 cents. Now it's for anyone who cleans beaches away from a road system or who has a boat and signs up," said ITN's Tom Pogson, adding that they have budgeted for 20,000 pounds.

In late July, the network will provide all-expenses-paid trips to Tugidak Island at the southern tip of Kodiak for week-long cleanup stints. The money comes from a two-year NOAA restoration grant with a goal of removing 80,000 pounds.

"It's a stunning natural environment, and simply from the point of view of just being able to get there and see the place, a lot of people are volunteering. But we still have quite a few slots open," Pogson added with a laugh.

ITN also sponsors a Kodiak Coast Walk in June that includes 81 beaches. Pogson points out that help is always needed to handle all the junk once it comes to town.

Meanwhile, the state is reportedly set to get $1 million from the Japanese government dedicated for tsunami debris cleanup, but it is unclear when the money might be cut loose. Meanwhile, federal and state agencies have worked closely with Alaska groups to prioritize cleanup areas. The three hot spots are Kayak Island out of Prince William Sound, the outer coast of Hinchinbrook Island, the outer coast of the Kenai Peninsula and the northeast coasts of Afognak and Shuyak Islands.

Laine Welch is a Kodiak-based fisheries journalist. Her Fish Radio programs can be heard on stations around the state. Contact her at msfish@alaska.com.


Laine welch
Fisheries