Data from: Congruent patterns of connectivity can inform management for broadcast spawning corals on the Great Barrier Reef

Connectivity underpins the persistence and recovery of marine ecosystems. The Great Barrier Reef (GBR) is the world's largest coral reef ecosystem and managed by an extensive network of no-take zones; however, information about connectivity was not available to optimize the network's configuration. We use multivariate analyses, Bayesian clustering algorithms and assignment tests of the largest population genetic data set for any organism on the GBR to date (Acropora tenuis, >2500 colonies; >50 reefs, genotyped for ten microsatellite loci) to demonstrate highly congruent patterns of connectivity between this common broadcast spawning reef-building coral and its congener Acropora millepora (~950 colonies; 20 reefs, genotyped for 12 microsatellite loci). For both species, there is a genetic divide at around 19°S latitude, most probably reflecting allopatric differentiation during the Pleistocene. GBR reefs north of 19°S are essentially panmictic whereas southern reefs are genetically distinct with higher levels of genetic diversity and population structure, most notably genetic subdivision between inshore and offshore reefs south of 19°S. These broadly congruent patterns of higher genetic diversities found on southern GBR reefs most likely represent the accumulation of alleles via the southward flowing East Australia Current. In addition, signatures of genetic admixture between the Coral Sea and outer-shelf reefs in the northern, central and southern GBR provide evidence of recent gene flow. Our connectivity results are consistent with predictions from recently published larval dispersal models for broadcast spawning corals on the GBR, thereby providing robust connectivity information about the dominant reef-building genus Acropora for coral reef managers.

种群连通性是海洋生态系统存续与恢复的核心支撑。大堡礁（Great Barrier Reef, GBR）是全球规模最大的珊瑚礁生态系统，由覆盖广泛的禁捕区网络管护；但此前尚无可用的连通性数据以优化该管护网络的布局配置。本研究依托大堡礁迄今针对任一生物类群构建的最大规模种群遗传数据集，该数据集以指状轴孔珊瑚（Acropora tenuis）为研究对象，涵盖超过2500个珊瑚群体、50余处礁体，对10个微卫星位点（microsatellite loci）完成基因分型；同时整合其同属物种米氏轴孔珊瑚（Acropora millepora）的相关数据，该物种包含约950个珊瑚群体、20处礁体，对12个微卫星位点完成基因分型。本研究运用多元分析、贝叶斯聚类算法以及种群遗传归属检验方法，证实这两种同步喷卵型造礁珊瑚之间存在高度一致的连通性模式。两个物种均在南纬19°附近呈现遗传分界，这大概率反映了更新世时期的异域分化过程。南纬19°以北的大堡礁礁体基本属于泛交种群（panmictic），而南部礁体则呈现显著的遗传分化，具有更高的遗传多样性与种群遗传结构，其中以南纬19°以南近岸与远岸礁体间的遗传细分最为突出。大堡礁南部礁体所呈现的较高遗传多样性这一整体一致的模式，大概率是通过向南流动的东澳洋流（East Australia Current）实现的等位基因积累所导致的。此外，大堡礁北部、中部与南部的珊瑚海（Coral Sea）海域礁体与陆架外礁体间存在遗传混合信号，这为近期的基因流提供了佐证。本研究得到的连通性结果与近期发表的大堡礁同步喷卵型珊瑚幼虫扩散模型预测结果一致，从而为珊瑚礁管理者提供了关于优势造礁珊瑚属——轴孔珊瑚属（Acropora）的可靠连通性数据。