Oyster Grow-Out Cages Function as Artificial Reefs for Temperate Fishes

Abstract

We compared relative fish density, growth, and disappearance rates (mortality plus emigration) at three oyster grow-out sites, six natural rocky reefs, and one artificial reef purposely built for fish habitat. All sites were located within Narragansett Bay, Rhode Island. Trap surveys were conducted in the summer and autumn of 2004 and 2005 with a range of trap types designed to sample juvenile and adult fishes. Cunners Tautogolabrus adspersus were more abundant on natural rocky reefs and the artificial reef than on oyster grow-out sites, whereas scup Stenotomus chrysops and tautogs Tautoga onitis displayed the opposite pattern and were most abundant on aquaculture sites. The relative density of black seabass Centropristis striata was similar in all habitats. A mark-recapture study on scup indicated that this species grew at higher rates on natural rocky reefs but had a lower disappearance rate from aquaculture sites. Based on these criteria, the oyster grow-out cages provide good-quality habitat for fishes typically associated with hard-bottom habitats. Habitat restoration programs for these fishes should thus consider use of grow-out cages alongside other types of artificial reefs.