Jones Karina, Jensen Michael, Burgess Graham, Leonhardt Johanna, van Herwerden Lynne, Hazel Julia, Hamann Mark, Bell Ian, Ariel Ellen
College of Public Health, Medical and Veterinary Sciences, James Cook University of North Queensland, Townsville, Australia.
Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, Queensland, Australia.
PeerJ. 2018 Sep 28;6:e5651. doi: 10.7717/peerj.5651. eCollection 2018.
A solid understanding of the spatial ecology of green turtles () is fundamental to their effective conservation. Yet this species, like many marine migratory species, is challenging to monitor and manage because they utilise a variety of habitats that span wide spatio-temporal scales. To further elucidate the connectivity between green turtle rookeries and foraging populations, we sequenced the mtDNA control region of 278 turtles across three foraging sites from the northern Great Barrier Reef (GBR) spanning more than 330 km: Cockle Bay, Green Island and Low Isles. This was performed with a newly developed assay, which targets a longer fragment of mtDNA than previous studies. We used a mixed stock analysis (MSA), which utilises genetic data to estimate the relative proportion of genetically distinct breeding populations found at a given foraging ground. Haplotype and nucleotide diversity was also assessed. A total of 35 haplotypes were identified across all sites, 13 of which had not been found previously in any rookery. The MSA showed that the northern GBR (nGBR), Coral Sea (CS), southern GBR (sGBR) and New Caledonia (NC) stocks supplied the bulk of the turtles at all three sites, with small contributions from other rookeries in the region. Stock contribution shifted gradually from north to south, although sGBR/CS stock dominated at all three sites. The major change in composition occured between Cockle Bay and Low Isles. Our findings, together with other recent studies in this field, show that stock composition shifts with latitude as a natural progression along a coastal gradient. This phenomenon is likely to be the result of ocean currents influencing both post-hatchling dispersal and subsequent juvenile recruitment to diverse coastal foraging sites.
深入了解绿海龟的空间生态学对于其有效保护至关重要。然而，与许多海洋洄游物种一样，由于绿海龟利用跨越广泛时空尺度的多种栖息地，对其进行监测和管理具有挑战性。为了进一步阐明绿海龟繁殖地与觅食群体之间的连通性，我们对来自大堡礁北部（GBR）超过330公里的三个觅食地点（蚬贝湾、绿岛和低岛）的278只海龟的线粒体DNA控制区进行了测序。这是通过一种新开发的检测方法进行的，该方法针对的线粒体DNA片段比以前的研究更长。我们使用了混合群体分析（MSA），该分析利用遗传数据来估计在给定觅食地发现的遗传上不同的繁殖群体的相对比例。还评估了单倍型和核苷酸多样性。在所有地点共鉴定出35种单倍型，其中13种以前在任何繁殖地都未发现。混合群体分析表明，大堡礁北部（nGBR）、珊瑚海（CS）、大堡礁南部（sGBR）和新喀里多尼亚（NC）的种群为所有三个地点的大部分海龟提供了来源，该地区其他繁殖地的贡献较小。种群贡献从北向南逐渐变化，尽管sGBR/CS种群在所有三个地点都占主导地位。组成的主要变化发生在蚬贝湾和低岛之间。我们的研究结果与该领域最近的其他研究一起表明，种群组成随着纬度的变化而自然地沿着沿海梯度变化。这种现象可能是洋流影响孵化后幼体扩散以及随后幼体向不同沿海觅食地补充的结果。
