Connectivity, the demographic linking of local populations through the dispersal of individuals, is one of the most poorly understood processes in population dynamics, yet has profound implications for conservation and harvest strategies. For marine species with pelagic larvae, direct estimation of connectivity remains logistically challenging and has mostly been limited to single snapshots in time. Here, we document seasonal and interannual patterns of larval dispersal in a metapopulation of the coral reef fish Amphiprion polymnus. A 3-year record of larval trajectories within and among nine discrete local populations from an area of approximately 35 km was established by determining the natal origin of settled juveniles through DNA parentage analysis. We found that spatial patterns of both self-recruitment and connectivity were remarkably consistent over time, with a low level of self-recruitment at the scale of individual sites. Connectivity among sites was common and multidirectional in all years and was not significantly influenced by seasonal variability of predominant surface current directions. However, approximately 75% of the sampled juveniles could not be assigned to parents within the study area, indicating high levels of immigrations from sources outside the study area. The data support predictions that the magnitude and temporal stability of larval connectivity decreases significantly with increasing distance between subpopulations, but increases with the size of subpopulations. Given the considerable effort needed to directly measure larval exchange, the consistent patterns suggest snapshot parentage analyses can provide useful dispersal estimates to inform spatial management decisions. © 2012 Blackwell Publishing Ltd.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We thank Chris McKelliget, Vanessa Messmer, Juan David Arango, Jennifer Smith, Agnes Rouchon and the Motupore Island Research Centre staff for assistance in the field. Nuria Raventos assisted with otolith analyses. The ARC Centre of Excellence for Coral Reef Studies, the National Science Foundation (OCE 0424688), the Coral Reef Initiatives for the Pacific (CRISP), the TOTAL Foundation, Populations Fractionees et Insulares (PPF EPHE) and the Connectivity Working Group of the global University of Queensland-World Bank-Global Environmental Facility project, Coral Reef Target Research and Capacity Building for Management provided financial support. Special thanks to Motupore Island Research Centre, Dik Knight and Loloata Island Resort for logistic support.
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics