Fisheries Service studies surge in salmon sharks

JUNEAU (AP) -- The National Marine Fisheries Service is launching a study to learn more about a surge in the number of salmon sharks in Alaska waters.

Starting in July, NMFS research biologist Lee Hulbert will head up a two-year program that will tag and track salmon sharks in Prince William Sound and the Gulf of Alaska.

''There has been a huge, unprecedented increase in shark numbers in the past decade but there's not a lot of data available,'' Hulbert told the Juneau Empire.

Although salmon sharks are one of the predominant shark species in Prince William Sound and the Gulf of Alaska, very little is known of the species trends in abundance, demographics, ecology or seasonal movements.

Throughout the 1990s, sightings of sharks and incidental catches of them in fisheries in Southeast and Southcentral Alaska have increased dramatically. A significant increase in the shark population has the potential to hurt recovery of fish species affected by the 1989 Exxon Valdez oil spill, Hulbert said.

''Sharks in large numbers can also affect populations of both commercially and economically viable species,'' he said.

Funded by Exxon Valdez Oil Spill Trustee Council, the Alaska Salmon Shark Assessment Project is designed to collect data on the species' abundance, movement and migrations, and seasonal residency in Prince William Sound and the Gulf of Alaska.

''This is the first directed shark research program conducted in Alaska,'' Hulbert said.

Hulbert, along with four other scientists and a crew from the National Geographic Society, plan to tag and release as many salmon sharks as they can catch while aboard the research vessel ''Montague'' over a 10-day period.

''Last year when we went out on the pilot study, we caught 70 sharks in five days,'' Hulbert said.

This summer Hulbert's team plans to tag the dorsal fins and implant data-collecting devices in the sharks.

''We have data loggers that we surgically implant in the shark that will tell us how often they eat, what time they eat and what depth they're feeding at -- basically where these sharks like to hang out,'' he said.