Scientists get crabby
Crab declines among topics to be discussed at Sea Grant/Lowell Wakefield Fisheries Symposium
Symposium information and agenda available on the web at http://seagrant.uaf.edu/conferences/
Short video clip of molting
ANCHORAGE, Alaska—Although Kodiak, Alaska, scientist Brad Stevens recently found six crab species never before seen in Alaska waters, there's still a lot about crabs scientists don't know. This month, scientists will meet in Anchorage, Alaska, to exchange research results on everything from how old king crabs are when they molt, to how male Dungeness crabs prevent other males from impregnating female crabs they've taken a fancy to.
"Over the past three decades we haven't been very successful at maintaining commercially viable crab fisheries in Alaska," said Gordon Kruse, a marine fisheries scientist with the Alaska Department of Fish and Game (ADF&G). "This symposium is an important vehicle to discuss our situation with some of the world's top crab scientists. We'll be able to contrast crab species in the North Pacific with those from other marine ecosystems around the globe, and share new technologies and approaches to gain insights into the roles of man versus nature on exploited crab populations."
Crab biologists and managers will meet at Anchorage's Regal Alaskan Hotel for four days beginning January 17, 2001, to reveal what they've learned about crabs that inhabit the world's cold waters. The 19th Alaska Sea Grant/Lowell Wakefield Symposium will host crab experts from Europe, North America, South America, Japan, and Australia. Researchers and managers will present findings on crab reproduction, behavior, management strategies and economics.
One of the issues driving crab research is the crash of Alaska's opilio, or snow crab, fishery. Harvest quotas have been slashed by managers to protect stocks that show signs of being overfished. Curbing the snow crab fishery is expected to cost fishermen millions of dollars in lost revenue this year.
Scientists led by Laurence Byrne, formerly of the Alaska Department of Fish and Game, will compare the abundance of snow crabs as measured by the annual management trawl survey and the actual commercial catch. Others will discuss reproductive issues of snow crab such as the influence of temperature on the development of snow crab embryos. Robert Otto, director of the National Marine Fisheries Service Laboratory in Kodiak, Alaska, will present new methods for measuring crab abundance that may improve the results of annual trawl surveys.
Johnathan Warrenchuk, a graduate student at the University of Alaska Fairbanks, will present findings from his study on effects of wind-chill on undersize snow crab held on fishing vessels prior to release. By law undersize crabs must be released. But they sometimes die after being exposed to cold air during the winter fishing season.
Jennifer Boldt, also a student from UAF, will present findings that show Dungeness crab larvae constitute as much as 65 percent of the prey consumed by pink salmon in the northern Gulf of Alaska. The finding may help explain declines in Dungeness crab stocks that may be due, in part, to large-scale production of pink salmon by hatcheries in Prince William Sound.
Shareef Siddeek, a shellfish biometrician with ADF&G, will discuss methods to improve estimates of natural mortality among king crabs. These estimates are crucial to improving the models that determine how much crab fishermen are allowed to catch.
Francine Bennis and Dorothy Childers, of the Alaska Marine Conservation Council, will present an overview of the snow crab fishery decline, citing rapid growth of the fishery amid a lack of biological information about the stock.
Fritz Funk, a biometrician with the Alaska Department of Fish and Game, will discuss the use of satellites to monitor crab fishing in the Bering Sea. The satellites allow managers to understand how vessels conduct the fishery amid pack ice some 600 miles from the nearest ADF&G management office.
Brad Stevens, a crab biologist with the National Marine Fisheries Service in Kodiak, will bring a list of the 71 crab species found in Alaska waters. It's a list that's bound to draw attention, since six species were only recently discovered by Stevens to inhabit Alaska waters. One species, Macroregonia macrochira, was discovered atop seamounts 11,000 feet beneath the ocean off Alaska. This crab has never before been identified in U.S. waters. Stevens has given the species the common name "long-clawed spider crab."
The Alaska Sea Grant College Program is a marine research, education and outreach service headquartered at the University of Alaska Fairbanks, School of Fisheries and Ocean Sciences. Sea Grant is funded by the National Oceanic and Atmospheric Administration in partnership with the state of Alaska and private industry.
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