Quantifying dispersal between marine protected areas by a highly mobile species, the bottlenose dolphin, Tursiops truncatus

Ecol Evol. 2018 Aug 23;8(18):9241-9258. doi: 10.1002/ece3.4343. eCollection 2018 Sep. . Nykänen M1, Dillane E1, Englund A1, Foote AD2, Ingram SN3, Louis M4,5,6, Mirimin L7, Oudejans M8, Rogan E1. Author information 1 School of Biological, Earth and Environmental Sciences University College Cork Cork Ireland. 2 School of Biological Sciences Molecular Ecology Fisheries Genetics Lab Bangor University Bangor UK. 3 School of Biological and Marine Sciences Plymouth University Plymouth UK. 4 Centre d'Etudes Biologiques de Chizé UMR 7372 CNRS-Université de La Rochelle La Rochelle France. 5 Observatoire Pelagis UMS 3462 CNRS-Université de La Rochelle La Rochelle France. 6 Scottish Oceans Institute University of St Andrews St Andrews UK. 7 Department of Natural Sciences School of Science and Computing Galway-Mayo Institute of Technology Marine and Freshwater Research Centre Galway Ireland. 8 Kelp Marine Research Hoorn The Netherlands. Abstract The functioning of marine protected areas (MPAs) designated for marine megafauna has been criticized due to the high mobility and dispersal potential of these taxa. However, dispersal within a network of small MPAs can be beneficial as connectivity can result in increased effective population size, maintain genetic diversity, and increase robustness to ecological and environmental changes making populations less susceptible to stochastic genetic and demographic effects (i.e., Allee effect). Here, we use both genetic and photo-identification methods to quantify gene flow and demographic dispersal between MPAs of a highly mobile marine mammal, the bottlenose dolphin Tursiops truncatus. We identify three populations in the waters of western Ireland, two of which have largely nonoverlapping core coastal home ranges and are each strongly spatially associated with specific MPAs. We find high site fidelity of individuals within each of these two coastal populations to their respective MPA. We also find low levels of demographic dispersal between the populations, but it remains unclear whether any new gametes are exchanged between populations through these migrants (genetic dispersal). The population sampled in the Shannon Estuary has a low estimated effective population size and appears to be genetically isolated. The second coastal population, sampled outside of the Shannon, may be demographically and genetically connected to other coastal subpopulations around the coastal waters of the UK. We therefore recommend that the methods applied here should be used on a broader geographically sampled dataset to better assess this connectivity. KEYWORDS: MPAs; bottlenose dolphins; connectivity; photo‐identification; population structure PMID: 30377497 PMCID: PMC6194238 DOI: 10.1002/ece3.4343 Free PMC Article