Abstract

Recruitment is a major factor in the establishment and sustenance of local population structures of reef fishes. Insights on temporal and spatial recruitment variability are crucial to understanding the population dynamics of these commercially and recreationally targeted species. The distribution, abundance and recruitment variation of young-of-the-year mutton snapper (Lutjanus analis), lane snapper (L. synagris), schoolmaster snapper (L. apodus), gray snapper (L. griseus), and yellowtail snapper (Ocyurus chrysurus) were examined in relation to environmental parameters and habitat in the Middle Florida Keys between 2007 and 2019. Interannual variability in juvenile abundance was high, with 3 to 50-fold differences in mean predicted abundance between the highest and lowest producing years by species. Predicted abundances of mutton, lane, schoolmaster, and yellowtail were lowest in 2010, the year of a historic cold spell in South Florida. In contrast, juvenile gray snapper abundance was highest in that year. Strong seasonal trends were seen in abundance indices for all species, with peak predicted abundances all occurring in the fall. Among spatial and environmental variables, within-site differences in distance from shore, aquatic vegetation type, and aquatic vegetation cover were the most important predictors of abundance. Gray, lane, and schoolmaster all had pronounced, positive associations with Halodule wrightii, while yellowtail abundance was significantly explained by Thalassia testudinum cover. Our findings underscore species-specific life history differences among shallow water snappers and provide management- relevant information on year class strength in the Florida Keys.

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