Potential effects of climate change on living species are a widely debated topic. Species with temperature-dependent sex determination can be particularly impacted by warmer temperatures because unbalanced sex ratios could threaten population viability. In sea turtles, sex ratio estimates have highlighted the potential feminization of current populations, which tends to increase since warmer temperatures would generate more females. Here, we evaluated temporal variation in sex ratios of green turtles from feeding grounds of the Southwest Atlantic Ocean (SWA) using data from a 7-year time frame, from 2010 to 2016. We also evaluated natal origins of female and male green turtles from SWA based on mitochondrial DNA. Sex ratios of juvenile and adult green turtles were generally female-skewed across collection years. We identified 11 haplotypes in northeast SWA, and the haplotype composition of females and males was slightly different. Likewise, the estimated the natal origins of females and males were divergent. Ascension Island was estimated to be the main source of females while Guinea Bissau was estimated to be the main source of males. Studies evaluating natal origins of females and males independently are rare, this study provides one of the first assessments of the kind for green turtles in the SWA.

中文翻译：

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西南大西洋觅食地绿海龟的性别比和出生起源

气候变化对生物物种的潜在影响是一个备受争议的话题。具有温度依赖性性别决定的物种可能会受到温度升高的特别影响，因为不平衡的性别比例可能会威胁种群生存能力。在海龟中，性别比估计突出了当前种群潜在的女性化趋势，由于温度升高会产生更多的雌性，这种趋势往往会增加。在这里，我们使用 2010 年至 2016 年 7 年时间范围内的数据评估了西南大西洋 (SWA) 觅食地绿海龟性别比的时间变化。我们还评估了来自SWA 基于线粒体 DNA。幼年和成年绿海龟的性别比例在整个收集年份中普遍偏向雌性。我们在SWA东北部鉴定出11个单倍型，雌性和雄性的单倍型组成略有不同。同样，估计的女性和男性的出生起源是不同的。阿森松岛估计是女性的主要来源，而几内亚比绍估计是男性的主要来源。独立评估雌性和雄性出生起源的研究很少见，这项研究提供了对 SWA 中绿海龟的首批评估之一。