Abstract

Anthropogenic effects and severe tropical weather have critically compromised some of Florida’s natural coastal habitats, including oyster reefs, seagrasses, and mangroves. Many ecologically and economically important reef fishes in Florida waters depend on healthy estuarine ecosystems for nursery habitat before undergoing ontogenetic shifts to deeper habitats as they increase in size and age. Gray snapper typify this pattern of estuarine-dependency as they rely on mangroves and seagrass beds during early life. We examined gray snapper recruitment potential among estuarine and coastal systems from four regions along the west Florida shelf in an effort to link habitat with recruitment. Juvenile snapper (n = 324) were sampled with a 6.1 m otter trawl and a 21.3 m center bag seine using a stratified random sampling protocol within systems monthly from August through December in 2006. Juvenile density was significantly different among sampling regions and habitat types (ANOVA, p < 0.01). Fish age was estimated from daily-formed opaque zones in lapilli. Growth functions computed from size-at-age data were significant among regions (ANCOVA test for slopes, p < 0.001). Results suggest region-specific differences in recruitment potential exist among estuarine and coastal systems along the west Florida shelf. Future work will involve a second year of trawl and seine sampling to examine interannual differences. We also will examine otolith element and stable isotope signatures among regions in an effort to link inshore recruitment dynamics with eventual recruitment to adult populations offshore.

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