Ecological Evaluation of Sedge Island Marine Conservation Area in Barnegat Bay : Final Report, 2013

Abstract

Conservation zones are important for maintaining the sustainability of ecosystems and populations of economically important species. The relative ecological value, especially for economically important species, of the Sedge Island Marine Conservation Zone (SIMCZ) in Barnegat Bay, NJ was assessed by comparing the following inside the SIMCZ with areas outside the conservation zone: (1) abundance and species diversity of fish and select decapod crustaceans in three habitats (seagrass, macroalgae, and unvegetated) using throw traps, (2) population structure of adult blue crabs using commercial-style traps, and (3) brood production of adult female blue crabs. Throw trap sampling indicates that blue crabs are most abundant in seagrass as compared to unvegetated habitats. Overall, blue crabs are more abundant outside the SIMCZ than inside but the difference does not apply to each habitat, suggesting the habitats inside and outside the SIMCZ are at least equivalent. Inside and outside the conservation area, species diversity is enhanced in both structured habitats as compared to unvegetated areas and is similar inside the SIMCZ as compared to outside. Again, this suggests the SIMCZ is at least equivalent to a comparative area outside the conservation zone. The SIMCZ has greater abundance of adult blue crabs, a sex ratio that is more skewed towards males, and a greater proportion of ovigerous females that are about to spawn and show signs of recent spawning. This suggests that the SIMCZ may provide refuge from fishing, particularly for male blue crabs, and may be an important area for spawning females.