Invasive Crabs Inventory at Assateague Island National Seashore - Open Format Dataset

An invasive crab inventory survey was performed to document the abundance and spatial distribution of the European green crab (Carcinus maenas) and the Japanese shore crab (Hemigrapsus sanguineus) at Assateague Island National Seashore (ASIS) which forms the eastern boundaries of Chincoteague and Sinepuxent Bays. Three habitat types (rocky, vegetated and unvegetated) are present within the Chincoteague and Sinepuxent Bays. Each habitat type was sampled to determine if different habitat types support different populations of these invasive crabs. Rocky habitat is known to be limited in these bays and there are only seven known locations of this habitat type. Crab traps were placed at randomly assigned stations where tidal elevations are within the known range and preferences of the invasive crabs.

Throughout two surveys representing July and September conditions, 15 species were collected and only one species was identified as an invasive crab. Only three C. maenas were captured throughout the project. These individuals were captured during the July survey at one of the rocky habitat stations. No invasive crab species were collected at either the vegetated or unvegetated habitats. Discrete water quality parameters that were measured during the initial deployment indicate that temperature and salinity at the survey stations may be at the extreme end of this species tolerance.