Data from: Translocation of wild populations: conservation implications for the genetic diversity of the black-lipped pearl oyster Pinctada margaritifera

Translocation has been widely studied as a tool for conservation management to restore or enhance degraded populations. On the contrary few studies have been conducted on translocation for commercial purposes. In this study we evaluate the genetic consequences of translocation of wild individuals of Pinctada margaritifera on farmed and adjacent wild populations. We tested the hypotheses that translocations would induce high genetic heterogeneity in farmed populations and this heterogeneity would then leak into the adjacent wild populations. In fact, farmed samples exhibit high levels of heterogeneity and low pairwise relatedness compared to wild populations, highlighting the pooling of genetically divergent populations into farms. We also demonstrate that this heterogeneity is transmitted to adjacent wild populations as a result of interbreeding. Adjacent wild populations tend to have higher genetic diversity values and greater pairwise relatedness coefficient with farmed populations than wild populations. Overall pearl culture in French Polynesia promotes the mixing of unrelated individuals in farmed locations and reduces genetic divergence among geographically distant populations as well as among farmed and wild populations of a same lagoon. We also studied for the first time, a farmed population originating from spat collected in a lagoon where release of hatchery produced larvae occurred ten year ago and we were able to identify four distinct genetic groups. These groups contribute highly to reproduction and caused considerable genetic drift in the lagoon, suggesting that hatchery produced larvae are neither sustainable method for pearl culture nor for conserving the diversity of P. margaritifera in French Polynesia.

种群移殖（translocation）作为恢复或改善退化种群的保护管理手段已得到广泛研究。与之相反，针对商业用途开展的种群移殖研究却寥寥无几。本研究针对黑蝶珍珠贝（Pinctada margaritifera）的野生个体移殖行为，评估其对养殖种群及邻近野生种群的遗传影响。本研究验证了两项假说：其一，种群移殖会使养殖种群产生较高的遗传异质性；其二，该异质性会扩散至邻近的野生种群。结果显示，相较于野生种群，养殖样本的遗传异质性更高，且两两亲缘关系更低，这表明养殖场内汇集了遗传背景差异显著的种群。本研究同时证实，这种遗传异质性会通过种间杂交扩散至邻近的野生种群。相较于其他野生种群，邻近的野生种群往往具备更高的遗传多样性，且与养殖种群的两两亲缘系数更高。总体而言，法属波利尼西亚的珍珠养殖活动促使养殖区域内无亲缘关系的个体发生混合，并降低了地理间隔较远种群间的遗传分化，同时也缩小了同一泻湖内养殖种群与野生种群间的遗传差异。本研究还首次对一个养殖种群展开分析：该种群的幼贝采自十年前曾放生过孵化场繁育幼体的泻湖，本研究团队成功鉴定出四个独立的遗传类群。这些遗传类群对泻湖内的繁殖活动贡献显著，并引发了显著的遗传漂变，这表明孵化场繁育的幼体既非珍珠养殖的可持续手段，亦无法有效保护法属波利尼西亚黑蝶珍珠贝的种群多样性。