Status of blue crab, Callinectes sapidus, populations in the Maryland Coastal Bays

The blue crab, Callinectes sapidus, is a valuable resource in the Coastal Bays, supporting a steady commercial and recreational fishery. Surveys suggest that blue crab abundance fluctuates without an apparent trend, yet there is still a successful annual commercial fishery that even attracts crabbers from the Chesapeake Bay. Since 1990, commercial landings for crabs have averaged from 0.5 to 1.5 million pounds. Commercial landings for 2003 were 1.17 million pounds. Unlike Chesapeake Bay landings data, these appear to fluctuate without trend. During 2003, the fishery independent trawl and seine survey caught a total of 6,754 blue crabs. An examination of 2,627 legal blue crabs taken by trawl net over a 13year period indicates no decline in average size, suggesting minimal increases in fishing pressure. Like commercial landings, these catches have generally fluctuated without trend. Environmental and hydrographic factors play a key role in blue crab recruitment (movement into the Coastal Bays). One factor that may affect blue crab populations is a parasite (Hematodinium sp.) that kills crabs in late summer and fall. Blue crabs may also be threatened by the presence of invasive species such as green and Asian shore crabs (Carcinus maenas and Hemigrapsus sanguineus). A. Blue crab abundance Introduction The blue crab, Callinectes sapidus, is a valuable resource to the Coastal Bays ecosystem and the commercial and recreational efforts it supports. Since 1990, commercial landings for crabs have averaged from 0.5 to 1.5 million pounds annually. The Coastal Bays Fisheries project (CBFI) has conducted annual surveys of the Coastal Bays since 1972. Although blue crab monitoring is not an official component of the CBFI, some data is available through the CBFI and through reported catch data. Management Objective: Maintain optimum sustainable blue crab populations (MCBP CCMP objective FW 1.4) Maryland’s Coastal Bays: Ecosystem Health Assessment Chapter 8.6 8-83 Draft Blue crab Indicator: Abundance/ trends