Ongoing Research
Pacific sleeper shark genetics: Staff at ABL are investigating the population genetics of this species. Early results suggest that there are two distinct lineages of Pacific sleeper sharks that co-occur within the Gulf of Alaska and Bering Sea areas. This project is ongoing and staff are collaborating with scientists at the Department of Fish and Oceans Canada and the University of Windsor to further investigate genetics of the family of sleeper sharks.
Spiny dogfish age and growth: Spiny dogfish have historically been aged using the dorsal fin spine, but that method has a number of challenges associated with it. Scientists at ABL along with staff AFSC Age and Growth lab are investigating new methods examining vertebral thin sections. This project is funded by the North Pacific Research Board.
Caption
Map of the release and recovery locations along the Gulf coast for tags on Spiny Dogfish
Spiny dogfish migration and habitat use: Pop off satellite archival tags (PSATs) have been deployed on spiny dogfish since 2009. To date 183 tags have been deployed and data has been successfully recovered from 154 of those tags. The tags record temperature, depth and light level of the environement that the fish experiences. They are programmed to release from the animal on a pre-determined date then float to the ocean surface. At that point the tags transmit the stored data to orbiting satellites. Early results are showing that spiny dogfish appear to have complicated migration patterns and cover large areas.
Shark species in Alaska
There are three species of sharks that are abundant in Alaska waters: Pacific sleeper shark, Somniosus pacificus, spiny dogfish, Squalus suckleyi , and salmon shark, Lamna ditropis. Currently there is no directed fishing for these species, but they are caught incidentally in other fisheries. Little is known about these sharks’ life histories in Alaska, but research on their ages, natural mortality, movements, diets, and maturity is ongoing.
Pacific Sleeper Sharks Pacific sleeper sharks are the largest of the shark species encountered in the Gulf of Alaska and Bering Sea, growing up to 7 meters. This species ranges as far north as the Arctic Circle in the Chukchi Sea, west off the Asian coast and the western Bering Sea, and south to California. Pacific sleeper sharks are the most abundantly caught shark in the Bering Sea surveys, yet catches are unreliable and do not provide good estimates of biomass. The species feeds mostly on fish, cephalopods, and sometimes marine mammals, and although they were once thought to be bottom dwelling, it is now known that they use much of the water column. This species has proven very difficult to age and due to the large size they are difficult to sample. Thus, little is known about their growth, longevity, the age at which they become mature, and the length of gestation.
Pacific sleeper sharks caught on a research vessel in the Gulf of Alaska.
Tagged spiny dogfish ready for release.
Salmon shark caught on a research cruise in southeast Alaska.
Spiny Dogfish Spiny dogfish in the North Pacific Ocean are a distinct species (S. suckleyi), but were until recently considered the same species as those spiny dogfish (S. acanthias) found on the U.S. east coast and other oceans of the world. Subsequently, much of the research refers to S. suckleyi as S. acanthias. Spiny dogfish range from the Bering Sea to the Baja Peninsula with the center of abundance believed to be in the waters around Washington State and British Columbia (Canada). In the Gulf of Alaska, spiny dogfish are the most prominent shark species in the NMFS biennial trawl surveys and annual longline survey. This species has been heavily fished in both British Columbia and Washington State, but they have only ever been a bycatch species in the Gulf of Alaska.
Spiny dogfish are the most well studied of the three main shark species in the Gulf of Alaska. Numerous studies have been published or are ongoing regarding this species. Spiny dogfish are longest lived and slowest growing of all shark species studied, living to 100 years or more and females do not reach maturity until they are 36 years old. Reproduction is also slow for this species, gestation takes nearly 2 years and females have about 9 pups on average. Diet studies shown that spiny dogfish do not target specific prey. Instead, they are opportunistic, feeding on whatever is available. Tagging studies are showing that spiny dogfish can undertake large scale migrations, moving from Canadian waters to Japan or Mexico, and they may inhabit areas previously unknown, such as pelagic waters far from shore.
Salmon Sharks
Salmon sharks range from Japan through the Bering Sea and Gulf of Alaska and south to Baja, Mexico. Salmon sharks are rarely encountered in commercial fisheries or trawl surveys in federal waters, but are more commonly caught in salmon fisheries and research surveys conducted by the Alaska Department of Fish and Game in nearshore waters. The species is also targeted by sport fishermen in Alaska, but catches are low. Tagging studies show that some animals may migrate thousands of kilometers south while others may over winter in Alaskan waters. Salmon shark tend to congregate during the summer in areas with dense salmon runs, especially Prince William Sound, Alaska, but they also feed on squid, sablefish, rockfish, eulachon, spiny dogfish, arrowtooth flounder, and Pacific cod.
Contact:
Cindy Tribuzio
Auke Bay Laboratories
Alaska Fisheries Science Center, NOAA Fisheries
Ted Stevens Marine Research Institute
17109 Pt Lena Loop Rd
Juneau AK 99801
(907) 789-6007 Cindy.Tribuzio@noaa.gov
Featured Research, Publications, Posters, Reports, and Activities
TRIBUZIO, C., D. CLAUSEN, C. RODGVELLER, J. HEIFETZ, and D. ALCORN. 2008. Research, biology, and management of sharks and grenadiers in Alaska. AFSC Quarterly Report Feature (April-May-June 2008) 9 p. (.pdf, 656KB). Online.
COURTNEY, D. L., and L. HULBERT.
2007. Shark research in the Gulf of Alaska with satellite, sonic, and archival tags, p. 26-27. In P. Sheridan, J. W. Ferguson, and S. L. Dowling (editors), Report of the National Marine Fisheries Service Workshop on Advancing Electronic Tag Technologies and Their Use in Stock Assessments. U.S. Dep. Commer., NOAA Tech. Memo. NMFS-F/SPO-82.
SIGLER, M. F., L. B. HULBERT, C. R. LUNSFORD, N. THOMPSON, K. BUREK, G. O’CORRY-CROWE, and A. C. HIRONS.
2006. Diet of Pacific sleeper shark, a potential Steller sea lion predator, in the northeast Pacific Ocean. J. Fish Biol. 69:392-405.
