The Case of the Incredible Shrinking Fish

Alaska’s halibut are growing to just a fraction of their normal size—and no one knows why.
They might look big, but Alaska's halibut are dramatically smaller than they were 20 years ago. (Photo: Rich Reid/Getty Images)
Dec 6, 2011· 1 MIN READ
Clare Leschin-Hoar's stories on seafood and food politics have appeared in Scientific American, Eating Well and elsewhere.

In fishery-management, sometimes things can unexpectedly go haywire despite careful stock assessments and thoughtfully determined catch-limit recommendations. In Alaska, the latest mystery is swirling around nearly everybody’s favorite fish: halibut.

It turns out that halibut stocks remain plentiful, but the fish are maturing at a very slow pace, and scientists aren’t sure what’s causing the phenomenon.

“It happened with halibut once before in the 1920s and ’30s,” said Julie Speegle, Public Affairs Officer for NOAA Fisheries Service, Alaska Region. “It might be a natural cyclical thing or something to do with environmental factors. We don’t know. What we do know is that there are lots of halibut, but they’re smaller.”

Steven Hare, assessment biologist for the International Pacific Halibut Commission, which recommended a 20 percent cut in quotas last week, says it’s a mystery to them as well.

“We do believe the total biomass is declining,” Hare says, “but the big question is why the fish are much, much smaller than they used to be.”

He says that 25 years ago, a 15-year-old female weighed about 100 pounds. Today, that same fish weighs 30 pounds. “It could be a fishing effect, or it could be a large number of fish are competing for a limited resource base,” Hare says. “We just don’t know.”

The Alaska Dispatch is using headlines sprinkled with words like “Halibut Armageddon” and “Suddenly Shrinking Populations,” and has raised questions about illegal fishing and an ongoing dispute between commercial fishers and charter boat operators as possible reasons the fish may seemingly be in trouble.

For commercial fishermen, this is the seventh year in a row the IPHC has recommended a cut in allowable catches. The Commission is scheduled to meet in late January to make their final decision on the recommendations.

For now, wild-caught Alaskan halibut will remain on the Seafood Watch’s green “best choice” list, despite the turmoil over the stocks.

“One of the key factors in Seafood Watch is management of a stock. A fish may still be “green” if the appropriate responses are being taken in regards to the abundance of the stocks,” says Ken Peterson, spokesman, Monterey Bay Aquarium.

Just be prepared to pay more for the tasty white fish. Less fish landed in 2012 means less fish on the market. Together, it’s a lesson in economics and environmentalism.