Crab: Dungeness

Dungeness crab

The Dungeness crab is distributed from the Aleutian Islands, Alaska, to Monterey Bay, California. They can be found as shallow as the intertidal zone to depths of 180 m. They are widespread and most abundant on sandy bottoms and in shallow waters associated with eelgrass.

Dungeness crabs have a “low” inherent vulnerability to fishing pressure, mostly due to their early age of first maturity.

Dungeness crab populations are fully exploited but are not considered overfished due to safeguards in the management strategy. Generally crab stocks appear healthy based on landings, however, there is little doubt that this species is “fully fished” and that the size and sex distributions are skewed from natural conditions. Overall this criterion is given a “yellow” ranking.

There is little or no problem with bycatch in this fishery, as Dungeness crabs are normally caught with traps or highly selective gear. Bycatch of other species is low relative to the weight of Dungeness crab landed. Although, the bycatch ratio has not been formally derived it is likely less than 1%. The main form of bycatch in this fishery is undersized, soft-shell or female crabs. Traps are required to have escape holes that are a minimum of 110 mm in diameter to allow undersized crabs to escape. Females, providing they are handled properly can be released without harm. The extent of bycatch is considered of “low” conservation concern.

Dungeness crabs are captured by trap gear on shallow sandy bottoms. This type of gear is thought to have some impact on bottom habitats from scouring by wave action and when the gear is retrieved, but shallow sandy bottoms are considered to be quite resilient to disturbance. The geographic scope of the fishery is moderate in that it is confined to shallow depths and specific areas. Capturing Dungeness crabs with traps is not likely to cause a major change in the ecosystem state. Overall this criterion is given a “moderate” ranking.

Overall the management technique applied has maintained stock productivity over time. This criterion is given a ranking of “low” conservation concern.