The Relative Importance of the Sedge Island Marine Conservation Zone for Adult Blue Crabs in Barnegat Bay, New Jersey

Marine protected areas have become an important tool for the management of commercially important species. The Sedge Island Marine Conservation Zone (SIMCZ) in Barnegat Bay is 15 years old, but its effectiveness has never been assessed. This study evaluated the relative importance of the SIMCZ for adult blue crabs by comparing the abundance and size frequency distribution of crabs inside the SIMCZ with physically similar locations outside the SIMCZ that (1) were nearby, providing straight-line access to Barnegat Inlet but varying in habitat, and (2) varied in distance from an inlet but shared the same habitat. The SIMCZ contained more ovigerous females than surrounding locations, but there were few other differences, probably because of variation in habitats. Compared with other submerged aquatic vegetation (SAV)-dominated areas, the SIMCZ contained more legal-sized males. One potential effect of the lack of commercial fishing inside the SIMCZ may be a preponderance of relatively large males. The SIMCZ also contained more females, especially ovigerous females, even compared with adjacent SAV-dominated areas with similar proximity to Barnegat Inlet. Taken together, these results suggest that the SIMCZ is unique as an SAV-dominated area important for adult male and female blue crabs, particularly females that are members of the current spawning stock.