Habitat‐Specific Growth in Juvenile Pinfish

Abstract

AbstractUnderstanding how certain fish species utilize estuarine habitats is critical for future conservation and management efforts. Habitats with various types of structure, including seagrass, marsh, oyster reef, and nonvegetated bottom, provide transient juvenile fishes with food and refuge from predation. Relative growth rates and survival of species like the pinfish Lagodon rhomboides should depend on the distribution and relative abundance of such habitats within and among bay systems. In many bays, marsh makes up a larger proportion of habitat area than the more often‐studied seagrass, but habitat‐specific comparisons of fish growth have rarely included marsh. Using field enclosures, we compared relative growth of juvenile pinfish in marsh, oyster, and nonvegetated bottom habitats in Grand Bay National Estuarine Research Reserve, Mississippi. Mean growth rates of pinfish juveniles in two summer experiments were 0.39, 0.20, and 0.04 mm/d in marsh, oyster, and nonvegetated bottom habitats, respectively. Growth in marsh habitat was significantly higher than growth in oyster and nonvegetated bottom habitats and was consistent across the two summers of our experiments. From available literature, juvenile pinfish densities are consistently higher in vegetated habitats (marsh and seagrass) than in nonvegetated habitats. Our results indicate that marsh habitat may also provide better foraging options for juvenile pinfish. When combined with evidence from other studies, our results suggest that marsh habitat provides a critical nursery function for juvenile pinfish, especially in estuaries such as Grand Bay, where seagrass habitat is limited.