Abstract

Few artificial reefs (ARs) have received intensive, long-term study. In 1999, a small “patch” (~177 m2) AR was created in an undisclosed location 72 km off the coast of Georgia, United States, in 26 m of water. Ten-sec videos (77,593) were recorded hourly by up to six diurnally operated cameras viewing ~ 360o. Through September 2008, 106 taxonomic identifications included 40 benthic resident species, 34 mid-water visitors, 12 benthic cryptic species, and 12 supra-benthic nomads. The six benthic "resident" fishes/groups (Haemulon aurolineatum, Rhomboplites aurorubens, Balistes capriscus, Chaetodipterus faber, Centropristis sp. and Mycteroperca sp.) exhibited unexpectedly low presence (range: 4 - 50%). A Generalized Additive Model explained more deviation in residents’ presence (26.4 ± 2.4%; mean ± SE) than a Generalized Linear Model (18.9 ± 2.7%), among 13 covariate terms across species. Year, the interaction between temperature and salinity and season each explained more variance than water temperature or salinity, suggesting that yearly and seasonal conditions may have contained multiple factors not among those measured. Significant inter-annual trends in presence between 2000 and 2008, were shown by C. faber (Atlantic spadefish) downward during the spring seasons and by R. aurorubens (vermilion snapper) upward during the summer seasons. Despite their low short-term presence and high variability, the frequency of observations of resident fishes of the patch reef remained relatively stable over eight years. This study reinforced the utility of fixed remote video for assessment of long- and short-term temporal trends.

PDF Preview