Banks Sam C, Piggott L Maxine P, Williamson Jane E, Bové Ulysse, Holbrook Neil J, Beheregaray Luciano B
Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia.
Ecology. 2007 Dec;88(12):3055-64. doi: 10.1890/07-0091.1.
Understanding the scale of marine population connectivity is critical for the conservation and sustainable management of marine resources. For many marine species adults are benthic and relatively immobile, so patterns of larval dispersal and recruitment provide the key to understanding marine population connectivity. Contrary to previous expectations, recent studies have often detected unexpectedly low dispersal and fine-scale population structure in the sea, leading to a paradigm shift in how marine systems are viewed. Nonetheless, the link between fine-scale marine population structure and the underlying physical and biological processes has not been made. Here we show that patterns of genetic structure and population connectivity in the broadcast-spawning and long-distance dispersing sea urchin Centrostephanus rodgersii are influenced by physical oceanographic and geographic variables. Despite weak genetic differentiation and no isolation-by-distance over thousands of kilometers among samples from eastern Australia and northern New Zealand, fine-scale genetic structure was associated with sea surface temperature (SST) variability and geography along the southeastern Australian coast. The zone of high SST variability is characterized by periodic shedding of eddies from the East Australian Current, and we suggest that ocean current circulation may, through its influence on larval transport and recruitment, interact with the genetic consequences of large variance in individual reproductive success to generate patterns of fine-scale patchy genetic structure. If proven consistent across species, our findings suggest that the optimal scale for fisheries management and reserve design should vary among localities in relation to regional oceanographic variability and coastal geography.
了解海洋种群连通性的规模对于海洋资源的保护和可持续管理至关重要。对于许多海洋物种而言，成年个体为底栖生物且相对不活动，因此幼体扩散和补充模式是理解海洋种群连通性的关键。与先前的预期相反，最近的研究常常发现海洋中意外低的扩散和精细尺度的种群结构，这导致了对海洋系统看法的范式转变。尽管如此，精细尺度的海洋种群结构与潜在的物理和生物过程之间的联系尚未建立。在这里，我们表明，产卵扩散且远距离传播的海胆罗氏刺冠海胆（Centrostephanus rodgersii）的遗传结构和种群连通性模式受物理海洋学和地理变量的影响。尽管来自澳大利亚东部和新西兰北部的样本在数千公里范围内遗传分化较弱且不存在距离隔离，但精细尺度的遗传结构与澳大利亚东南海岸的海表温度（SST）变异性和地理特征相关。高SST变异性区域的特征是东澳大利亚海流周期性地脱落涡旋，我们认为洋流循环可能通过其对幼体运输和补充的影响，与个体繁殖成功率的巨大差异所产生的遗传后果相互作用，从而产生精细尺度的斑块状遗传结构模式。如果经证明在物种间具有一致性，我们的研究结果表明，渔业管理和保护区设计的最佳尺度应根据区域海洋学变异性和海岸地理特征在不同地区有所不同。
