Abstract

To examine the role of cyclic environmental parameters and stochastic hydrodynamic events on the delivery of fish larvae to shallow coral reefs along a major western boundary current, a series of light traps was deployed over shallow coral reefs along the upper Florida Keys every other night for six months from May-October of 2002 and 2003. Wind speed, current velocity, and water temperature were measured concurrently. In total, 27,649 larval fishes from 55 families, encompassing pelagic, mesopelagic, seagrass and reef species, were collected during the two year time series. Besides small silvery fishes in the families Clupeidae, Engraulidae, and Atherinidae, the collections were dominated by the families Pomacentridae, Chaenopsidae, Tripterygiidae, Gerreidae, Labrisomidae, Opistognathidae, Scaridae, Labridae, Scorpaenidae, Lutjanidae, Monocanthidae, and Sphyraenidae. The temporal nature of larval delivery in the study area appears both cyclic and episodic. Physical data indicated that 2 - 3 mesoscale eddies associated with the Tortugas Gyre passed through the study area each year, each with a residence time of several days. Such eddies caused a weakening or reversal of the mean northeast flow. The relative influence of these mesoscale features was taxon specific. Results from this study will improve our understanding of the dynamics of larval fish supply and how it is affected by physical environmental factors.

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