Understanding the potential for estuarine habitat types to predict juvenile Dungeness crab densities
On this page:
Shellfish production is a well-known and important ecosystem service of estuaries throughout the world, but the contribution of wetland habitat types to that production has not been characterized for U.S. Pacific Northwest estuaries. In Oregon, Dungeness crabs (Cancer magister) provide recreational and commercial harvest opportunities that make it the most economically valuable fisheries species in the state. Crab larvae settle and grow in estuaries and on the continental shelf, but those reared in estuaries grow faster and are larger at reproductive maturity. Extensive summertime trawl surveys and intertidal habitat surveys were conducted within four Oregon estuaries (Tillamook, Yaquina, Alsea, and Coos) to test the hypothesis that juvenile Dungeness densities are more positively correlated with seagrass (Zostera marina) habitat than other habitat types (e.g., burrowing shrimp and bare mudflat habitats), both within and across estuaries. Preliminary analyses indicate that the positive influence of burrowing shrimp habitat on juvenile crab density may be greater than that of seagrass habitat, contradictory to our initial hypothesis. We also examine the geospatial relationships between juvenile Dungeness crabs and the distribution of National Wetlands Inventory (NWI) habitat classes, channel size, salinity, and water temperature. Results from this study provide resource managers with valuable information for prioritization of habitat types for restoration, conservation, or enhancement for the purpose of increasing the abundance of Dungeness populations valued by local fisheries.