Abstract

As anthropogenic impacts increase, it is critical to understand how the consequences will affect commercially important fisheries species. Many of these species, like yellowtail snapper (Ocyurus chrysurus), depend on seagrass beds as critical nursery habitat. Since 2002, a non-native seagrass, Halophila stipulacea, has become widespread throughout the Caribbean, arriving in St. Thomas in 2013. The impacts of H. stipulacea on juvenile yellowtail snapper habitat is not well understood, yet, has the potential to disrupt essential fish habitats and reduce important fishery resources. Previous studies have demonstrated that H. stipulacea can reduce juvenile fish abundance, species diversity, and condition factor, suggesting that H. stipulacea may have a strong negative affect on growth and survival of juvenile reef fishes. In this study we analyzed the impacts of H. stipulacea on the settlement, mortality, and health of juvenile yellowtail snapper. Preliminary results suggest that there is a higher settlement frequency in H. stipulacea seagrass beds than in Syringodium filiforme seagrass habitats, however not than Thalassia testudinum seagrass habitats. Additionally, individuals caught in H. stipulacea seagrass habitats had a significantly higher condition factor, measurement of health, than individuals caught in native S. filiforme, but no significant difference than individuals caught in native T. testudinum. These data can be used in ecosystem-based fisheries management to better understand the best management practices for H. stipulacea in order to properly allocate resources for a more sustainable future for Caribbean reef fishes.

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