A Comparison of Fish and Epibenthic Assemblages on Artificial Reefs With and Without Copper-Based Anti-Fouling Paint

Abstract

Artificial reefs attract fish, but whether or not actual production occurs remains unclear. To examine this question, fish and epibenthic assemblages were compared between reefs with and without copper-based anti-fouling paint treatment. Artificial reefs (n = 60) were constructed approximately 28 km south of Dauphin Island, Alabama, in the Hugh Swingle reef-building zone. Twenty reefs (n = 20) were constructed during October 2005 (Reef Set 1), and forty reefs (n = 40) were constructed during July 2006 (Reef Set 2). Each reef consisted of twelve concrete blocks (20 X 20 X 41 cm) with four break-away sample bricks arranged on a plywood base (1.48 m2) that were placed on the bottom at 20 m depths. Half of the reefs (n = 30) were coated with copper-based anti-fouling paint and the other half (n = 30) were left unpainted. Reef Set 1 was surveyed 1 week, 2, 7, 10, and 14 months after deployment, and Reef Set 2 was surveyed 11 months after deployment. During each survey, two SCUBA divers visually estimated the abundance and size of all fish species. Break-away sample bricks were removed from reefs for later identification and measurement of epibenthic organisms. Copper painted reefs showed significantly lower mean total epibenthos coverage, biomass, diversity, and richness compared to unpainted reefs. Epibenthic assemblages also showed significant patterns of succession over the duration of the study period and no “climax” was reached. Observed patterns in fish recruitment were correlated with epibenthic assemblages on artificial reefs. Mean total fish abundance, diversity, and richness were significantly greater on unpainted compare to painted reefs. Red snapper, Lutjanus campechanus (Poey); wrasse, Halichoeres spp., (Rüppell); bank sea bass, Centropristis ocyurus (Jordan & Evermann); rock sea bass, Centropristis philadelphica (L.); blenny, Blenniidae spp.; and Atlantic spadefish, Chaetodipterus faber (Broussonet), showed significantly higher abundances on unpainted versus painted reefs. Additionally, fish assemblages showed significant seasonal patterns with time. This study showed that epibenthic assemblages affected recruitment of fishes to artificial reefs. Since these epibenthos are known food items for many reef fishes, our findings support the contention that artificial reefs result in increased fish production, not simply attraction.