Spatio-temporal variation in the genetic composition of wild populations of pearl oyster (Pinctada margaritifera cumingii) in French Polynesia following 10 years of juvenile translocation

The genetic impact of the cultural practice of spat collection and translocation between genetically distinct stocks of black-lipped pearl oyster, Pinctada margaritifera cumingii, was studied by comparing samples collected in the 1980s and 2000s from seven atolls in French Polynesia. An AMOVA revealed homogenization of the previously genetically distinct wild stocks of Tuamotu-Gambier and Society archipelagos (the indices of genetic differentiation among archipelagos and among populations within archipelagos, respectively, Phi(CT) and Phi(ST), decreased from 0.032* and 0.025*, respectively, to 0.006(NS) and 0.007(NS)). These results suggest high success of spontaneous reproduction in farms, probably due to the very high density of cultivated pearl oysters, and underline the importance of genetic monitoring of future hatchery produced stocks.