The relationship between large predatory fish and recruitment and mortality of juvenile coral reef-fish on artificial reefs

Predation on recently settled reef fishes is thought to potentially alter their patterns of recruitment. This paper describes observations of recruitment and mortality of pomacentrid recruits on artificial reefs constructed at two distances from natural reefs with differing numbers of large predatory fish. Subsequent patterns of recruit abundance ( < 3 wks old) on the artificial reefs were not obscured by post-recruitment mortality due to predation. These results motivated an experiment designed to assess whether predation pressure on artificial reefs was representative of predation pressure on natural reefs. The results indicated that prey on artificial reefs were less likely to encounter large predatory fish than prey on natural reefs. Tethered fish disappeared at a greater rate on natural reefs than on artificial reefs, and such losses were minimal within cages that excluded large predatory fish. These findings highlight the potential for predation pressure to vary among different habitat types and a need for care when choosing the habitats in which to study the effects of predation. Copyright (C) 1997 Elsevier Science B.V.