IRSTEA EABX, Aquatic Ecosystems and Global Changes Research Unit, 50 Avenue de Verdun, 33612, Cestas, France.
University of Bordeaux, UMR CNRS EPOC 5805, Allée Geoffroy Saint-Hilaire - CS 50023, 33615, Pessac Cedex, France.
Environ Sci Pollut Res Int. 2020 Feb;27(4):3651-3660. doi: 10.1007/s11356-018-4021-8. Epub 2019 Jan 10.
European sturgeon Acipenser sturio is an anadromous fish species being classified "critically endangered" with only one remaining population in the Gironde-Garonne-Dordogne basin (France). In the global warming context, this paper aims to determine the sensitivity of A. sturio early life phases to temperature and oxygen saturation. Embryos were experimentally exposed to a combination of temperature (12 to 30 °C) and oxygen (30 to 90% O saturation) conditions. Lethal and sublethal effects were evaluated using embryonic mortality, hatching success, malformation rate, yolk sac resorption, tissue development and swimming speed. Embryonic survival peaked at 20 °C and no survival was recorded at 30 °C regardless of the associated oxygen saturation. No hatching occurred at 50% O sat or below regardless of temperature. Malformation frequency appeared to be minimum at 20 °C and 90% O sat. Swimming speed peaked at 16 °C. The temperature optimum of early life phases of A. sturio was determined to be close to 20 °C. Its upper tolerance limit is between 26 and 30 °C and its lower tolerance limit is below 12 °C. Oxygen depletion induces sublethal effects at 70% O sat and lethal effects at 50% O sat. Within the spawning period in the Gironde-Garonne-Dordogne basin, we identified yearly favourable oxythermal windows. Consequences of climate change would depend of the phenological adaptation of the species for its spawning period.
欧洲鲟 Acipenser sturio 是一种洄游鱼类，被列为“极度濒危”物种，在吉伦特-加龙-多尔多涅盆地（法国）仅剩一个种群。在全球变暖的背景下，本文旨在确定 A. sturio 早期生活阶段对温度和氧气饱和度的敏感性。胚胎通过实验暴露于温度（12 至 30°C）和氧气（30 至 90%氧气饱和度）条件的组合中。使用胚胎死亡率、孵化成功率、畸形率、卵黄囊吸收、组织发育和游泳速度来评估致死和亚致死效应。胚胎存活率在 20°C 时达到峰值，无论氧气饱和度如何，在 30°C 时均未记录到存活。无论温度如何，在 50%氧气饱和度或以下时均未孵化。畸形频率似乎在 20°C 和 90%氧气饱和度下最小。游泳速度在 16°C 时达到峰值。A. sturio 早期生活阶段的最佳温度被确定为接近 20°C。其上限耐受温度在 26 和 30°C 之间，下限耐受温度低于 12°C。氧气消耗在 70%氧气饱和度下会产生亚致死效应，在 50%氧气饱和度下会产生致死效应。在吉伦特-加龙-多尔多涅盆地的产卵期内，我们确定了每年有利的氧热窗口。气候变化的后果将取决于该物种产卵期的物候适应。
