Effects of habitat on settlement, growth, predation risk and survival of a temperate reef fish

Abstract

We measured adult density, settlement, post-settlement survival, recruitment success, predation risk and growth rate of the cunner Tautogolabrus adspersus in 4 distinct habitat types (rocky reef, cobble, seagrass and sand) in St. Margaret's Bay, Nova Scotia, Canada. Settlement was not affected by habitat type or by adult density. Post-settlement survival, recruitment success (defined as the density of juveniles present after an arbitrary period following settlement) and adult density varied with habitat and were positively correlated with habitat complexity. This pattern was diametrically opposed to the pattern of predation risk, which was negatively correlated with habitat complexity. Growth of juvenile cunner different between habitats but was unrelated to habitat complexity. Since the initial pattern of settlement was dramatically altered within a very short time, we concluded that habitat-mediated post-settlement processes play an important role in the population dynamics of cunner. The results of this study demonstrate the importance of habitat in determining growth rates, rates of post-settlement mortality and recruitment success.