ASFB Home > 2003 > Biological Invasions: Consequences for Parasites, Pathogens, Emerging Diseases, and Fisheries in the Marine Environment.

Reef-induced circulations and their influences on the distribution of presettlement fishes

Michael J. Kingsford¹, Scott C. Burgess¹, and Kerry Black²

¹School of Marine Biology and Aquaculture, James Cook University, Queensland 4811, Australia
²ASR Ltd Marine and Freshwater Consultants, PO Box 13048, Hamilton, New Zealand
Email: Michael.Kingsford@jcu.edu.au

Currents near coral reefs have the potential to influence the dispersal characteristics of coral reef fishes. Our aim was to identify retention ‘hotspots’ for fish larvae based on knowledge of near-reef circulations at One Tree Island, Great Barrier Reef. We used oceanographic data and hydrodynamic models to develop sampling designs stratified by oceanography. We focused on (1) whether the presence or absence of eddies could be used to predict the relative abundances of larvae around the reef and (2) whether areas near the reef had higher concentrations than areas away from the reef where reef-induced retention features do not occur. We also considered possible differences relating to passive and active taxa and whether fishes were reef or pelagic as adults. Net tows were restricted to surface waters because of the time constraints of tidal cycles. We concluded that eddies do not generate predictable differences in relative concentrations, but they influence trajectories to favour nearshore retention. Highest concentrations of the most abundant taxon (mullids) were caught at sites that were on the windward side of the reef. These data suggest that neustonic eggs and larvae are retained near the windward sides of reefs more effectively than on the leeward, despite the presence of eddies and strong tidal currents.

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