Faulks Leanne K, Gilligan Dean M, Beheregaray Luciano B
Department of Biological Sciences, Molecular Ecology Lab, Macquarie University Sydney, NSW, Australia.
Industry and Investment New South Wales, Batemans Bay Fisheries Office Batemans Bay, NSW, Australia.
Evol Appl. 2011 Jul;4(4):589-601. doi: 10.1111/j.1752-4571.2011.00183.x. Epub 2011 Jan 27.
Habitat fragmentation is one of the leading causes of population declines, threatening ecosystems worldwide. Freshwater taxa may be particularly sensitive to habitat loss as connectivity between suitable patches of habitat is restricted not only by the natural stream network but also by anthropogenic factors. Using a landscape genetics approach, we assessed the impact of habitat availability on population genetic diversity and connectivity of an endangered Australian freshwater fish Macquarie perch, Macquaria australasica (Percichthyidae). The relative contribution of anthropogenic versus natural in-stream habitat structures in shaping genetic structure and diversity in M. australasica was quite striking. Genetic diversity was significantly higher in locations with a higher river slope, a correlate of the species preferred habitat - riffles. On the other hand, barriers degrade preferred habitat and impede dispersal, contributing to the degree of genetic differentiation among populations. Our results highlight the importance of landscape genetics to understanding the environmental factors affecting freshwater fish populations and the potential practical application of this approach to conservation management of other freshwater organisms.
栖息地破碎化是导致种群数量下降的主要原因之一，威胁着全球的生态系统。淡水生物类群可能对栖息地丧失特别敏感，因为适宜栖息地斑块之间的连通性不仅受到自然溪流网络的限制，还受到人为因素的限制。我们采用景观遗传学方法，评估了栖息地可利用性对濒危澳大利亚淡水鱼麦夸里鲈（Macquaria australasica，鲈科）种群遗传多样性和连通性的影响。人为与自然河道内栖息地结构对麦夸里鲈遗传结构和多样性形成的相对贡献十分显著。在河流坡度较高的地方，遗传多样性显著更高，河流坡度与该物种偏好的栖息地——浅滩相关。另一方面，障碍物会破坏偏好的栖息地并阻碍扩散，导致种群间的遗传分化程度增加。我们的研究结果凸显了景观遗传学对于理解影响淡水鱼种群的环境因素的重要性，以及该方法在其他淡水生物保护管理中的潜在实际应用价值。
