Underwater Video Monitoring of Groupers and the Associated Hard-Bottom Reef Fish Assemblage of North Carolina

• Autores: Erin J. Burge, Craig Andrews, Benjamin M. Binder, Zachery D. Hart, Amanda C Wood
• Localización: Bulletin of Marine Science, ISSN 0007-4977, Vol. 88, Nº. 1, 2012, págs. 15-38
• Idioma: inglés
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• Resumen

  • Groupers and their associated reef fish assemblage near Cape Fear, North Carolina, were observed using scuba and underwater stationary videography during a 7-mo period. Fifty-seven sites were visited with stationary video and diver point counts of groupers were taken at each site. Primary observations by both techniques were made on gag, Mycteroperca microlepis (Goode and Bean, 1879), and scamp, Mycteroperca phenax Jordan and Swain, 1884, while other grouper species were noted for videos only. Comparisons of gag and scamp density were made using baited and unbaited stationary camera deployments on high- and low-relief ledge habitats. Inferred minimum population sizes by location ranged from 0 to 4 gag, 0 to 13 scamp, and 0 to 2 yellowmouth, Mycteroperca interstitialis (Poey, 1860), using stationary video. Estimated densities by video camera were highest for scamp at 480 ha-1. Gag density was estimated at 145 ha-1 and yellowmouth grouper at 50 ha-1. In total, 68 fish species including groupers were recorded by video and richness by site ranged from 10 to 26 (n = 34; mean 18.9, SD 4.2). Reef fish community structure as measured by mean Bray-Curtis dissimilarity between paired sites was 0.339 (0.219 SD) indicating a substantial overlap in species composition between most sites. Given the economic importance of the snapper-grouper complex and the desire to develop non-extractive (or reduced impact) survey techniques, stationary video observations hold promise for monitoring changes in reef fish assemblages.