Climate change impacts on Dungeness crab

Using Bioenergetics Models to Evaluate Ecological and Fishery Impacts of Climate Change on Dungeness Crab

Scientists examine the effects of changing water temperature on Dungeness crab, Washington’s most valuable harvest, and develop bioenergetic models to guide management strategies.

Principal Investigator

P. Sean McDonald, UW Program on the Environment

Co-Principal Investigators

David Armstrong, UW School of Aquatic and Fishery Sciences

Project

Climate change puts Dungeness crab, Washington’s most valuable catch, at risk. They favor cooler water, while less-desirable graceful crab predominate in warmer parts of Puget Sound. Warmer temperatures can make crab grow faster, outstripping available resources. Males may molt earlier and reach harvestable size before reproducing. But little is known about how changing temperature and salinity and other climate-related factors will specifically affect Dungeness crab. Regulators need this information to determine fishing seasons and set harvest size. This research will divide Dungeness and graceful crabs of roughly equal size into tanks kept at six different temperatures and feed them standardized portions. Similar feeding trials conducted at a common temperature with crabs of various sizes will determine size-specific consumption rates. Bioenergetic models based on the data thus developed will be used to consider how future conditions may affect crab ecology and to evaluate the robustness of current management strategies.