Carbonell Ellgutter Jennifer A, Bik Ingrid Maria, Renssen Hans, Rosell Frank, Hawkes Lucy A, Reinhardt Stefanie
Department of Natural Sciences and Environmental Health, Faculty of Technology, Natural Sciences and Maritime Sciences University of South-Eastern Norway Bø Telemark Norway.
Section of Grid Licensing The Norwegian Water Resources and Energy Directorate Oslo Norway.
Ecol Evol. 2025 Jul 9;15(7):e71750. doi: 10.1002/ece3.71750. eCollection 2025 Jul.
Climate change poses a significant threat to species with temperature-dependent sex determination, such as sea turtles. Their conservation often involves relocating nests to hatcheries, which is also crucial on the Pacific coast of Guatemala, where virtually no hatchlings emerge from natural nests. Populations there rely heavily on hatcheries, yet nest temperature monitoring in relation to environmental and management factors is rarely conducted. Research is needed to improve artificial nest management and hatchery design. This study investigated how distance to the hatchery wall, number of eggs, position in the nest, development period, season, and weather conditions influenced temperature variation in Olive Ridley Turtle () nests. We generally found nest temperatures within viable ranges and near the pivotal temperature for Olive Ridleys. The pivotal temperature of Olive Ridley was exceeded 6%-21% of the time during the thermosensitive period of all nests (starting days 9-15 and ending days 33-37 of incubation), and the upper thermal tolerance limit was rarely reached. However, nests closer to concrete walls were up to 1°C warmer than those farther away, and 30-40 more eggs per nest raised average temperatures by 0.7°C. These findings suggest that distance to hatchery walls and egg numbers per nest can be tools to manipulate nest temperatures and sex ratios. The sex ratios in this study were slightly female-biased. However, optimal sex ratios remain poorly understood, and reliance on ex situ incubation may reduce population adaptability to environmental changes. Ex situ nest conditions in our study displayed lower temperatures than potential in situ conditions, which exceeded the lethal threshold in 86% (-test, < 0.001) of the measurements. Our study emphasizes the need for careful hatchery management to safeguard sea turtles against the effects of climate change but also to avoid the consequences of overcompensation due to mismanagement.
气候变化对具有温度依赖型性别决定的物种，如海龟，构成了重大威胁。它们的保护工作通常包括将巢穴转移到孵化场，这在危地马拉太平洋沿岸也至关重要，因为那里几乎没有幼龟从自然巢穴中孵化出来。当地的种群严重依赖孵化场，但很少有人针对环境和管理因素进行巢穴温度监测。因此，需要开展研究以改善人工巢穴管理和孵化场设计。本研究调查了孵化场墙壁的距离、卵的数量、在巢穴中的位置、发育时期、季节和天气条件如何影响丽龟巢穴的温度变化。我们通常发现巢穴温度处于可行范围内，且接近丽龟的关键温度。在所有巢穴的热敏期（孵化开始的第9 - 15天至结束的第33 - 37天），丽龟的关键温度有6% - 21%的时间被超过，且很少达到热耐受上限。然而，靠近混凝土墙壁的巢穴比远离墙壁的巢穴温度高出1°C，每个巢穴多30 - 40枚卵会使平均温度升高0.7°C。这些发现表明，到孵化场墙壁的距离和每个巢穴的卵数可以作为控制巢穴温度和性别比例的手段。本研究中的性别比例略微偏向雌性。然而，最佳性别比例仍知之甚少，而且依赖异地孵化可能会降低种群对环境变化的适应能力。我们研究中的异地巢穴条件显示的温度低于潜在原地条件下的温度，在86%（t检验，P < 0.001）的测量中，原地温度超过了致死阈值。我们的研究强调需要谨慎管理孵化场，以保护海龟免受气候变化的影响，同时避免因管理不善导致过度补偿的后果。
