Small spatial scale population genetic structure in two limpet species endemic to the Kermadec Islands, New Zealand

Persistence of marine species in isolated habitats requires either continuing recruitment from distant sources or self-recruitment from the local population. Species endemic to small isolated oceanic islands such as the SW Pacific Kermadec Islands (New Zealand) are reliant on self-recruitment for continued existence. Population genetic studies in such isolated habitats can provide data on the extent to which dispersal limits the occurrence of organisms and determines their genetic structure. We used randomly amplified polymorphic DNA markers (RAPDs) to examine genetic structuring and connectivity among populations of 2 intertidal limpets endemic to the Kermadec Islands. Significant genetic differentiation and limited connectivity were observed among populations of these limpets separated by less than 1 km, suggesting that a large proportion of successfully recruiting larvae do not disperse far from their population of origin. Patterns of connectivity may be explained partly by the geographic distance among populations, but the data suggest that other barriers to gene flow, most likely associated with local hydrographic features, contribute to the observed patterns of small-scale population genetic structuring.