Temporal patterns in the larval supply of summer-recruiting reef fishes to Lee Stocking Island, Bahamas
Thorrold, S.R.; Shenker, J.M.; MojicaRaymond, J.; Maddox, E.D.; Wishinski, E.
Marine Ecology Progress Series 112(1-2): 75-86
Moored plankton nets were used to monitor the supply of settlement-stage reef fishes to benthic habitats on Great Bahamas Bank in the vicinity of Lee Stocking Island, Exuma Sound, Bahamas. A total of 55 771 fishes, representing 53 taxa, were captured in 79 d of sampling from June to September 1992. Reef fish larvae were extremely abundant in the samples, particularly the families Labridae, Apogonidae, Balistidae, Ophichthidae and Scaridae. Almost all fish were taken in night collections, and discrete tide sampling suggested most settlement-stage fishes were moving onshore during flood tides. Vertical distributions were taxon specific, with some taxa concentrated in surface nets while others were more abundant in mid-water collections. Larval supply of a number of taxa occurred almost entirely during several days around the new moon in early July, while other families showed more consistent, although still episodic, replenishment patterns. Time series analysis found evidence of semi-lunar cycling in the larval supply of scarids and ophichthids, lunar cycling in gobiids, bothids and apogonids, and acyclic replenishment in clupeids, blennioids, labrids and balistids. Cross correlations between larval supply and meteorological and hydrographic variables found significant associations in the families Gobiidae, Apogonidae, Blennioidei and Labridae. Significant correlations were driven by a large pulse of replenishment of all these taxa coinciding with a relaxation of southeast trade winds. This event apparently caused a reversal in the direction of longshore currents and generated significant onshore current flow. Settlement-stage larvae may have been transported from the northern region of Exuma Sound to Lee Stocking Island. Alternatively, larvae may have been entrained from offshore waters in the southern Sound and advected across the shelf to reef areas.