Do Blue Crab Spawning Sanctuaries in North Carolina Protect the Spawning Stock

Abstract

AbstractSpawning sanctuaries located at the five major inlets to Pamlico Sound, North Carolina, as well as various harvest controls, have not been adequate to protect the spawning stock of the blue crab Callinectes sapidus. We conducted an extensive trawl survey within Pamlico and Croatan sounds as well as five inlet spawning sanctuaries during 2002 to quantify the spatiotemporal use of spawning sanctuaries by mature female blue crabs and to identify potential migration corridors to spawning grounds. The abundance of mature females was highest along the northwestern portion of Pamlico Sound, suggesting this is an important staging area for females before their seaward migration; however, there was no clear evidence of specific migration corridors. Mature female abundance was no different inside inlet sanctuary boundaries versus 1‐2 km outside sanctuary boundaries, and sanctuaries only protect 44.9% and 0.7% of the current local inlet and Pamlico Sound‐wide spawning populations, respectively, of mature female blue crabs. In general, the abundance of mature female blue crabs was higher at inlets located to the extreme north or south in Pamlico Sound than at inlets located in the central portion of the sound. The results from this study suggest that the particular geometry and placement of inlet spawning sanctuaries are not adequate to protect the North Carolina blue crab spawning stock, and other management options should be considered, such as (1) a double sanctuary and migration corridor system located in northern and southern portions of Croatan and Pamlico sounds coupled with either (2) reduction of fishery effort on females or (3) seasonal closures.