Larval supply: a good predictor of recruitment of three species of reef fish (Pomacentridae)

This study investigated the hypothesis that recruitment variations of coral reef fish directly reflect vanations in larval supply. At Lizard Island, northern Great Barrier Reef, larval supply and recruitment of 3 species of damselflsh (Pomacentrus amboinensis, P. nagasakiensis and Dischistodus perspicillatus) were estimated from light trap and patch reef collections respectively, over 2 con- secutive recruitment seasons, in each of 3 habitats. Comparison of these patterns pooled over species and seasons revealed a good overall correlation between larval supply and early recruitment levels, suggesting that pre-settlement distributions may be the major determinant of early recruitment patterns despite mediating influences from factors such as habitat selection and post-settlement mortality. This result also supports the use of broad recruitment surveys to estimate year-class strength and to hindcast patterns in larval supply. When analysed at the individual species/season level, the abundance of recruits on patch reefs and the abundance of larvae in light trap collections were also significantly correlated, with the exception of one species (l? amboinensis) during one season (1989/90). When the level of comparison was further narrowed to analyse correlations between preand post-settlement fish of individual species in each season, wlthin each habitat, only 7 significant relationships were detected out of a possible 18 habitathpecies combinations. The power of these tests was relatively high (mean = 0.846; SE = 0.03). These relationships provide some evidence for habitat selection suggesting that P. amboinensis preferred the leeward habitat, while D. perspicillatus preferred the windward habitat.