Abstract

Nassau grouper are an important species in the Caribbean both in a fisheries context and because they contribute to tourism through enhanced diving experiences. However, the species has suffered dramatic declines through it range due to overfishing on fish spawning aggregations (FSAs) for the species. These spawning aggregations, occurring during the win-ter months in the central Caribbean, represent the total reproductive output for the species. It is thus important that we gain an understanding of the patterns of connectivity generated by FSA sites, and characterize the processes of egg/larval advec-tion, diffusion, and planktonic ecology (feeding and predation). To do this, we evaluated the ability of a novel plankton sampler, the NetCam, to map the dispersal of Nassau grouper eggs from the FSA immediately post-spawning. The NetCam captures images of items passing through the cod-end of a plankton net. However, it is not clear what proportion of the eggs imaged by the NetCam are Nassau grouper. Using eggs from preserved samples taken during the NetCam deployment, we demonstrate at least 3 distinct size classes of eggs. Based on genetic analysis, these distinct classes belong to separate spe-cies. These findings suggest that images of fish eggs captured by the NetCam can reliably be identified to species, and are thus useful in characterizing the spatial ecology and early life history of Nassau grouper eggs.

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