Great Lakes Institute for Environmental Research, University of Windsor, 401 Sunset Ave., Windsor, ON, N9B 3P4, Canada.
Heredity (Edinb). 2018 Jun;120(6):533-546. doi: 10.1038/s41437-017-0038-x. Epub 2018 Jan 10.
The globally invasive Round Goby (Neogobius melanostomus) was introduced to the Great Lakes around 1990, spreading widely and becoming the dominant benthic fish in many areas. The speed and scope of this invasion is remarkable and calls into question conventional secondary spread models and scenarios. We utilized nine microsatellites to identify large-scale genetic structure in Round Goby populations in the eastern Great Lakes, and assessed the role of colonization vs. secondary transport and dispersal in developing this structure. We identified three clusters, corresponding with Lake Huron, eastern Lake Erie, and western Lake Erie plus eastern Lake Ontario, along with three highly divergent populations. Bottleneck analysis identified founder effects in two divergent populations. Regression analyses of isolation by distance and allelic richness vs. distance from the initial invasion site were consistent with limited migration. However, some populations in eastern Lake Erie and Lake Ontario showed anomalously low genetic distance from the original site of colonization, consistent with secondary transport of large numbers of individuals via ballast water. We conclude that genetic structure of Round Goby in the Great Lakes principally resulted from long-distance secondary transport via ballast water with additional movement of individual via bait buckets and natural dispersal. The success of Round Gobies represents an interesting model for colonization characterization; however, those same attributes present significant challenges for conservation and fisheries management. Current management likely prevents many new species from arriving in the Great Lakes, but fails to address the transport of species within the lakes after they arrive; this is an issue of clear and pressing importance.
全球入侵的圆鳍鱼（Neogobius melanostomus）于 1990 年左右被引入五大湖，广泛传播，并成为许多地区占优势的底栖鱼类。这种入侵的速度和范围是显著的，这对传统的二次传播模型和情景提出了质疑。我们利用九个微卫星来确定五大湖东部圆鳍鱼种群的大规模遗传结构，并评估了定居与二次运输和扩散在形成这种结构中的作用。我们确定了三个聚类，分别对应休伦湖、伊利湖东部和伊利湖西部加上安大略湖东部，以及三个高度分化的种群。瓶颈分析确定了两个分化种群的奠基者效应。隔离距离与距离初始入侵点的等位基因丰富度的回归分析与有限的迁移一致。然而，伊利湖东部和安大略湖的一些种群与原始定居点的遗传距离异常低，这与通过压载水大量运输个体的二次运输一致。我们得出结论，五大湖圆鳍鱼的遗传结构主要是通过压载水的远距离二次运输形成的，而个体通过诱饵桶和自然扩散进行了额外的移动。圆鳍鱼的成功代表了一个有趣的定居特征模型；然而，这些相同的特征给保护和渔业管理带来了重大挑战。目前的管理可能阻止了许多新物种进入五大湖，但未能解决它们到达后的物种在湖泊内的运输问题；这是一个明显而紧迫的问题。
