Larval production drives temporal patterns of larval supply and recruitment of a coral reef damselfish

We examined the relative influence of planktonic processes and larval production on the larval supply and recruitment of the damselfish Pomacentrus arnboinensis during 2 summers at Llzard Island, northern Great Barrier Reef. Larval production was quantified by monitoring the nest sites of males in windward, lagoon and leeward habitats. Larval supply was estimated using light traps deployed in nearshore waters adjacent to the 3 habitats. Recruitment patterns were back-calculated from the otoliths of newly settled fish collected from small art~ficlal patch reefs constructed in each of the 3 habitats. Temporal patterns of spawning, larval supply and recru~tment were correlated when the spawning pattern was lagged by a period equivalent to the incubation time of eggs and the average planktonic life. This coupling occurred despite a change in the pattern of spawning between summers from occasional, large episodes to frequent, smaller pulses spread throughout the summer. Once regular cycles were removed from the data sets by ARIMA (integrated auto-regressive movingaverage) modelling, correlations between patterns declined or became non-significant. This suggests that reproduction has an important influence on the timing of recruitment, but that the magnitude of these events is largely determined within the plankton.