Dungeness crab exist in commercial quantities from Alaska to south of San Francisco, Calif. Along the Pacific coast, Dungeness crab live in the intertidal zone out to a depth of 170 meters. Washington’s coastal commercial crab grounds extend from the Columbia River to Cape Flattery near Neah Bay and include the estuary of the Columbia River, Grays Harbor, and Willapa Bay.
There is no stock assessment work conducted on coastal crab populations. Dungeness crab management on the coast is based on a minimum size limit of 6 1/4 inches, prohibition of harvest of female crab and a season closure during the primary male molt period. The minimum size limit assumes that male crab that are harvested have been sexually mature and have mated at least once before reaching legal size. Male crabs 6 1/4 inches or larger are assumed to be harvestable surplus; it is assumed that as much as 95 percent of the legal sized male crabs are harvested annually. In order for crab to grow they must shed their shell and expand to fill a new shell, this is referred to as molting.
During the early stage of the molt period crabs are soft and vulnerable to mortality due to handling; therefore, the coastal commercial fishery is closed from Sept.15 to early December. A Summer Fishery Management Plan was implemented in June of 2000 to protect crab that molt prior to the closure of the crab fishery in September. The plan is based on an intensive on-board sampling program designed to alert fishery managers if a large portion of the population begins molting prior to Sept.15.
Rather than shifting the management of the coastal crab fishery to a federal management plan, Congress in 1997 granted the states of Washington, Oregon and California jurisdiction to manage Dungeness crab fisheries outside state waters (3 to 200 miles offshore). This expanded jurisdiction enabled Washington to implement a pot limitation program affecting all crab fishers in coastal Washington waters beginning with the 1999-2000 season. This was an effort to slow the expansion of the fishery that began in the mid-1980s. This rapid expansion lead to an extremely competitive fishery where 50% of the season total is landed in the first 3-4 weeks of the 9-month season. In addition, in December 1994, Federal District Judge Edward Rafeedie upheld tribal shellfish harvest rights in Washington, ruling that Washington treaty tribes can harvest up to 50 percent of the harvestable shellfish in their usual and accustomed fishing grounds. These fishing grounds encompass approximately 50 percent of the Washington coastline.
Washington coastal Dungeness crab landing data back to 1950 shows a large fluctuation in harvest, ranging from a low of 2.5 million pounds in 1981 to a high of 25 million pounds in 2004-05 averaging at 9.5 million pounds. It is believed that this large fluctuation in landings is not a result of harvest patterns, but likely due to varying ocean conditions including, water temperature, food availability, and ocean currents.