Temporal and spatial patterns in the recruitment of coral-reef fishes in Barbados

We monitored the recruitment of 8 fish taxa at 10 d intervals for 1 yr on 5 fringing coral reefs along a 15 km stretch of the west coast of Barbados, using benthic standard monitoring units of recruitment of fishes (SMURFs). SMURFs are designed to sample taxa that settle onto coral rubble, including cryptic species, and to minimize post-settlement predation. We deployed SMURFs in reef habitat to separate meso-scale processes from the small-scale influences of benthic habitat. Recruitment of most taxa occurred year-round, but was highly variable, with on average more than 50% of recruits collected on only 14% of the sampling dates, indicating the importance of frequent sampling. Temporal patterns within taxa were concordant across reefs, indicating coast-wide synchronous settlement, but differed among taxa. Within reefs, 2 taxa settled more frequently on SMURFs surrounded by non-preferred substrate, 1 exhibited the opposite pattern, and the remaining 5 showed no substrate associations. Recruitment to individual SMURFs was seldom correlated among taxa. Among reefs, recruitment of 4 taxa was consistently lower on the central coast and higher at the north and south ends, consistent with a previously identified tidally induced flow regime that reduces onshore larval transport near the center of the west coast; the remaining taxa exhibited other spatial patterns, challenging the generality of the role of hydrodynamics. Overall, this study expands the taxonomic range of recruitment studies, shows spatially coherent (over kilometers) but temporally variable (over tens of days) recruitment and reveals substantial diversity in patterns among concurrently settling taxa.