Biophysical and Population Genetic Models Predict the Presence of "Phantom" Stepping Stones Connecting Mid-Atlantic Ridge Vent Ecosystems
Biophysical and Population Genetic Models Predict the Presence of "Phantom" Stepping Stones Connecting Mid-Atlantic Ridge Vent Ecosystems
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DOI：
10.1016/j.cub.2016.06.062
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发表时间：
2016-09-12
期刊：
影响因子：
9.2
通讯作者：
Reusch, Thorsten B. H.
中科院分区：
文献类型：
--
作者：
Breusing, Corinna;Biastoch, Arne;Reusch, Thorsten B. H.
深海热液喷口是零星分布的生态系统，居住着属于教科书元种群的专门动物种群。许多喷口相关的物种有自由游泳，分散的幼虫，可以建立远程种群之间的连接。然而，由于深海采样不足，迄今使用的分子工具分辨率有限，而且难以直接测量幼虫扩散情况，因此对热液喷口之间的连通模式仍然知之甚少。迫切需要更好地了解连通性，以制定健全的深海采矿环境管理计划。在这里，我们调查了幼虫扩散和当代连接的生态重要的喷口贻贝（Bathymodiolus属）。通过使用高分辨率海洋建模和种群遗传学方法，即使假设一个很长的远洋幼虫的持续时间，我们的物理模型的幼虫漂移表明，到达地方超过150公里，从源站点是不可能的，种群之间的传播需要中间的栖息地（“幻影”垫脚石）。扩散模式表现出很强的时空变异性，使预测人口的连通性具有挑战性。贻贝种群仅通过额外的垫脚石连接的假设得到了基于中性遗传标记的当代迁移率的支持。人口结构的分析证实，存在两个南方和两个杂交北方贻贝谱系，表现出实质性的，但不完整的，遗传分化。我们的研究提供了深入了解喷口动物可以分散在相距甚远的喷口栖息地，并表明扰动喷口网站的duponization将受到偶然事件，除非连接是明确考虑在保护区的选择。
Deep-sea hydrothermal vents are patchily distributed ecosystems inhabited by specialized animal populations that are textbook meta-populations. Many vent-associated species have free-swimming, dispersive larvae that can establish connections between remote populations. However, connectivity patterns among hydrothermal vents are still poorly understood because the deep sea is undersampled, the molecular tools used to date are of limited resolution, and larval dispersal is difficult to measure directly. A better knowledge of connectivity is urgently needed to develop sound environmental management plans for deep-sea mining. Here, we investigated larval dispersal and contemporary connectivity of ecologically important vent mussels (Bathymodiolus spp.) from the Mid-Atlantic Ridge by using high-resolution ocean modeling and population genetic methods. Even when assuming a long pelagic larval duration, our physical model of larval drift suggested that arrival at localities more than 150 km from the source site is unlikely and that dispersal between populations requires intermediate habitats ("phantom" stepping stones). Dispersal patterns showed strong spatiotemporal variability, making predictions of population connectivity challenging. The assumption that mussel populations are only connected via additional stepping stones was supported by contemporary migration rates based on neutral genetic markers. Analyses of population structure confirmed the presence of two southern and two hybridizing northern mussel lineages that exhibited a substantial, though incomplete, genetic differentiation. Our study provides insights into how vent animals can disperse between widely separated vent habitats and shows that recolonization of perturbed vent sites will be subject to chance events, unless connectivity is explicitly considered in the selection of conservation areas.