Of sharks, seals and ocean perch

March 29, 2007

Courtesy of  Far North Science
By Doug O'Harra
Scientists will tackle the mysteries of Bering Sea sharks and the decline of northern fur seals with studies funded by the Pollock Conservation Cooperative Research Center at the University of Alaska Fairbanks.

The center, underwritten largely by the pollock fishing industry but supervised by the UAF School of Fisheries and Ocean Sciences, awarded $300,000 in new grants for research into marine life off Alaska's vast coast.

In pursuit of abundant walleye pollock in the Bering Sea, fishermen inadvertently catch the groundfish's predators in the same trawls: salmon sharks and sleeper sharks. This bycatch ranges between 400 and 1,400 metric tons per season.

Salmon sharks - fast, blue-backed endotherms in the same family as Mako and Great Whites - roam Alaska waters during summer in a mysterious annual cycle. A large congregation of young females converge on Prince William Sound and Kenai Fjords areas to feast on summer salmon, for instance. But biologists know little about the behavior or numbers of other adults.

Sleeper sharks - stealthy, smooth-swimming behemoths once mistakenly thought to be sluggish - often travel just below the reach of light and seize their prey whole in immense mouths.

Led by UAF scientist Bob Foy, the shark project will compile existing data and then send biologists out with pollock catcher-processors into the Bering Sea to gather new information about shark demographics, health and ecology.

"Considerable support has been offered by the pollock industry, in particular by the At-Sea Processors, to adequately assess the potential impacts of shark bycatch so that informed mitigation efforts can be implemented," Foy wrote in his abstract.

Along with investigating shark ecology, other projects will investigate the ecology and dispersal of Pacific Ocean perch - possibly the most abundant rockfish in Alaskan waters of the North Pacific. UAF biologists A.J. Gharrett and T.J. Quinn II will look at genetics, dispersal and harvest. Pacific Ocean perch can live almost 100 years, yet start out their lives as tiny larva free-floating on the current.

Other projects will investigate the decline of Northern fur seals, the ecology of pollock and continue to operate a training program for seafood marketing and processing in Western Alaska.

The pollock research center was founded in 2000 with a grant from the Pollock Conservation Cooperative, a group of pollock fishing companies affiliated with the At-Sea Processors Association. The group has spent more than $7.4 million to fund at least 40 research projects.

Last year, pollock conservation center projects included a study of how fishermen interacted with Steller sea lions, partly investigating the possibility that shootings or harassment in past decades might have contributed to the 80 percent decline in the population. Other scientists looked into Kachemak Bay kelp forest habitat and genetics of chum salmon.