Rafferty Anthony R, Johnstone Christopher P, Garner Jeanne A, Reina Richard D
School of Biological Sciences, Monash University, Melbourne, Australia.
West Indies Marine Animal Research and Conservation Service, Frederiksted, St Croix, US Virgin Islands.
R Soc Open Sci. 2017 Oct 4;4(10):170196. doi: 10.1098/rsos.170196. eCollection 2017 Oct.
Unprecedented increases in air temperature and erratic precipitation patterns are predicted throughout the twenty-first century as a result of climate change. A recent global analysis of leatherback turtle hatchling output predicts that the nesting site at Sandy Point National Wildlife Refuge (SPNWR) will experience the most significant regional climate alterations. We aimed to identify how local air temperatures and precipitation patterns influenced within-nest mortality and overall hatchling output at this site between 1990 and 2010. We show that while the greatest mortality occurred during the latest stages of development (stage three), the rate of embryo mortality was highest during the initial stages (stage zero) of development (approx. 3.8 embryos per day per clutch). Increased mortality at stage three was associated with decreased precipitation and increased temperature during this developmental period, whereas precipitation prior to, and during stage zero had the greatest influence on early mortality. There was a significant decline in overall hatching success (falling from 74% to 55%) and emergence rate (calculated from the number of hatchlings that emerged from the nest as a percentage of hatched eggs) which fell from 96% to 91%. However, there was no trend observed in local temperature or precipitation during this timeframe, and neither variable was related to hatching success or emergence rate. In conclusion, our findings suggest that despite influencing within-nest mortality, climatic variability does not account for the overall decline in hatchling output at SPNWR from 1990 to 2010. Further research is therefore needed to elicit the reasons for this decline.
由于气候变化，预计整个21世纪气温将前所未有的升高，降水模式也将变得不稳定。最近一项对棱皮龟幼龟产量的全球分析预测，桑迪角国家野生动物保护区（SPNWR）的筑巢地将经历最显著的区域气候变化。我们旨在确定1990年至2010年间，当地气温和降水模式如何影响该地点巢内死亡率和幼龟总产量。我们发现，虽然最高死亡率发生在发育的最后阶段（第三阶段），但胚胎死亡率在发育的初始阶段（零阶段）最高（约每窝每天3.8个胚胎）。第三阶段死亡率的增加与该发育时期降水量减少和温度升高有关，而零阶段之前和期间的降水对早期死亡率影响最大。总体孵化成功率（从74%降至55%）和出壳率（根据从巢中孵出的幼龟数量占孵化卵数量的百分比计算）显著下降，出壳率从96%降至91%。然而，在此期间未观察到当地温度或降水的趋势，且这两个变量均与孵化成功率或出壳率无关。总之，我们的研究结果表明，尽管气候变异性影响巢内死亡率，但它并不能解释1990年至2010年间SPNWR幼龟产量的总体下降。因此，需要进一步研究以找出产量下降的原因。
