Data from: Historical and contemporary factors shape the population genetic structure of the broadcast spawning coral, Acropora millepora, on the Great Barrier Reef

Effective management of reef corals requires knowledge of the extent to which populations are open or closed and the scales over which genetic exchange occurs, information which is commonly derived from population genetic data. Such data are sparse for Great Barrier Reef (GBR) corals and other organisms, with the studies that are available being mostly based on a small number of sampling locations spanning only part of the GBR. Using 11 microsatellite loci, we genotyped 947 colonies of the reef-building coral Acropora millepora from 20 sites spanning almost the full length of the GBR (~12 degrees of latitude and ~1,550 km). The results show a major divide between the southernmost central to southern offshore populations and all other sampled populations. We interpret this divide as a signature of allopatric divergence in northern and southern refugia during the Pleistocene glaciations, from which the GBR was subsequently recolonised. Superimposed on this pattern is a cross-shelf genetic division, as well as a separation of inshore populations south of the Cape Clifton Front at ~21.5-22°S. Most inshore populations north of this, as well as mid-shelf populations in the northern and far northern GBR are open, exchanging recruits frequently. In contrast, inshore populations south of the Cape Clifton Front and offshore populations in the central and southern GBR are largely self-seeding, at least within the spatial resolution that was achieved given our sampling intensity. Populations that have been impacted by recent disturbance events causing extensive coral mortality show no evidence of reduced genetic diversity.对礁珊瑚实施有效管理，需明确其种群开放或封闭的程度，以及基因交流发生的尺度，而这类信息通常源自种群遗传学数据。大堡礁（Great Barrier Reef, GBR）珊瑚及其他生物的此类数据较为匮乏，现有相关研究大多仅基于覆盖大堡礁部分区域的少量采样点。本研究采用11个微卫星位点（microsatellite loci），对覆盖大堡礁近乎完整纬度跨度（约12个纬度，直线距离约1550千米）的20个采样点的947个米氏鹿角珊瑚（Acropora millepora）造礁珊瑚群体进行了基因分型。研究结果显示，最南端的中南部近海种群与其余所有采样种群之间存在显著的遗传分化。我们将该分化现象归因于更新世冰期（Pleistocene glaciations）期间南北避难所种群的异域分化（allopatric divergence），大堡礁后续的种群重建即源于此。在此基础之上，还存在跨陆架的遗传分化，以及分布于南纬约21.5°-22°的克利夫顿角锋面（Cape Clifton Front）以南的近岸种群的分化。该锋面以北的多数近岸种群，以及大堡礁北部和极北部的陆架中部种群均为开放种群，频繁进行幼体交换。与之相反，克利夫顿角锋面以南的近岸种群以及大堡礁中南部的近海种群则大多为自播种群，该结论至少在本研究采样强度所达到的空间分辨率范围内成立。近期受导致大规模珊瑚死亡的扰动事件影响的种群，未表现出遗传多样性降低的迹象。