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Fisheries Technician, Claire Cook, pulls a light trap to look for postlarval Dungeness crab. Photo credit: S. Grossman |
Dungeness crab are an important species in the Salish Sea because they support a lucrative commercial fishery in addition to filling a critical ecological role in marine food webs. Despite the importance of this species, very little research has been done with regard to the early life stages of Dungeness crab in Washington’s inland waters.
Our primary goals are to:
- better describe the population dynamics of Dungeness crab in our region,
- describe how the annual success of each year-class determines future harvestable crab populations,
- highlight limitations to the fishery, and
- assess the need for more adaptive harvest management practices through time.
Larval & Juvenile Dungeness Crab Research
In 2018, Swinomish Fisheries initiated a long-term research program in order to better understand the nuances of early-stage Dungeness crab settlement, development, and habitat use in parts of the Salish Sea. The aims of our research program target two distinct life-history stages. First, we are examining trends in the location and timing of the delivery of late-stage larvae through the use of devices called light traps. Second, we will evaluate how the timing and magnitude of larval delivery influences juvenile density and growth in nursery habitat through regular intertidal surveys. In addition, we are leading an effort to characterize the genetic diversity of Dungeness crab populations in the Pacific Northwest.
Fishery independent Monitoring
Swinomish Fisheries, along with other state and tribal co-managers, has taken the lead on developing fishery-independent monitoring protocols. This work involves scientists monitoring multiple aspects of sub-adult and adult Dungeness crab populations and biology on a year-round basis from research vessels. Fisheries staff plan to use commercial crab pots with closed escape rings, also referred to as ventless traps, in order to better characterize population structure, molting cycles, reproductive cycles, and seasonal movements. These data will help inform estimates of harvestable abundance and improve catch forecasting.
Interested to learn more? Check out publications related to our Dungeness crab research on the Swinomish publications web page.
We have or continue to partner with several individuals or organizations on some of our projects including: the Pacific Northwest Crab Research Group, Salish Sea Stewards, Sound Water Stewards, Padilla Bay NERR, Deception Pass State Park, Port of Anacortes, Whidbey Island Naval Airbase. Funding for aspects of this work was provided by SITC, the U.S. Environmental Protection Agency through a cooperative agreement #PA-0J127601, the U.S. Fish and Wildlife Service - Tribal Fish and Wildlife Program #F18AP00618 and #F22AP00495, and the Bureau of Indian Affairs - Tribal Resilience Program #A19AP00216 and #A21AP10152.