Centro de Estudios Avanzados en Zonas Áridas (CEAZA), Coquimbo, Chile; Laboratorio de Ecología y Conducta de la Ontogenia Temprana (LECOT), Coquimbo, Chile.
Laboratorio de Ecología y Conducta de la Ontogenia Temprana (LECOT), Coquimbo, Chile.
Sci Total Environ. 2020 Jun 1;719:137239. doi: 10.1016/j.scitotenv.2020.137239. Epub 2020 Feb 13.
We evaluated the effects of projected, near future ocean acidification (OA) and extreme events of temperature (warming or cooling) on the thermal tolerance of Concholepas concholepas, a coastal benthic keystone species. Three separate trials of an experiment were conducted by exposing juvenile C. concholepas for 1 month to one of two contrasting pCO levels (~500 and ~1200 μatm). In addition, each pCO level was combined with one of four temperature treatments. The control was 15 °C, whilst the other temperatures were 10 °C (Trial 1), 20 °C (Trial 2) and 25 °C (Trial 3). At the end of each trial, we assessed Critical Thermal maximum (CTmax) and minimum (CTmin) via self-righting success, calculated partial thermal tolerance polygons, measured somatic growth, determined transcription of Heat Shock Proteins 70 (HSP70) and measured oxygen consumption rates. Regardless of pCO level, HSP70 transcript levels were significantly higher in juveniles after exposure to extreme temperatures (10 °C and 25 °C) indicating physiological stress. Oxygen consumption rates increased with increasing temperature from 10 °C to 20 °C though showed a decrease at 25 °C. This rate was not affected by pCO or the interaction between temperature and pCO. Juveniles exposed to present-day and near future pCO levels at 20 °C showed similar thermal tolerance polygonal areas; whilst changes in both CTmin and CTmax at 25 °C and 10 °C caused narrower and broader areas, respectively. Temperature affected growth, oxygen consumption and HSP70 transcription in small juvenile C. concholepas. Exposure to elevated pCO did not affect thermal tolerance, growth or oxygen consumption at temperatures within the thermal range normally experienced by this species in northern Chile (15-20 °C). At elevated pCO conditions, however, exposure to warmer (25 °C) or colder (10 °C) temperatures reduced or increased the thermal area, respectively. This study demonstrates the importance of examining the thermal-tolerance edges to better understand how OA and temperature will combine to physiologically challenge inter-tidal organisms.
我们评估了未来近海水体酸化（OA）和温度极端事件（升温或降温）对沿海底栖关键种糙滨螺（Concholepas concholepas）热耐受性的影响。通过将幼年糙滨螺暴露于两种不同的 pCO2 水平（500 和1200 μatm）之一中，进行了三次独立的实验试验。此外，每个 pCO2 水平与四种温度处理中的一种相结合。对照为 15°C，而其他温度分别为 10°C（试验 1）、20°C（试验 2）和 25°C（试验 3）。在每个试验结束时，我们通过自行翻身成功评估了临界热最大值（CTmax）和最小值（CTmin），计算了部分热耐受多边形，测量了躯体生长，测定了热休克蛋白 70（HSP70）的转录水平，并测量了耗氧量。无论 pCO2 水平如何，暴露于极端温度（10°C 和 25°C）后的幼年糙滨螺 HSP70 转录水平显着升高，表明存在生理压力。耗氧量随温度从 10°C 增加到 20°C 而增加，但在 25°C 时减少。该速率不受 pCO2 或温度与 pCO2 之间相互作用的影响。在 20°C 下暴露于当今和未来 pCO2 水平的幼体表现出相似的热耐受多边形区域；而在 25°C 和 10°C 时 CTmin 和 CTmax 的变化分别导致更窄和更宽的区域。温度影响智利北部（15-20°C）该物种通常经历的温度范围内的小型糙滨螺幼体的生长，耗氧量和 HSP70 转录。在升高的 pCO2 条件下，暴露于更高的温度（25°C）或更低的温度（10°C）会分别减少或增加热区。这项研究表明，检查热耐受性边缘对于更好地理解 OA 和温度将如何结合对潮间带生物造成生理挑战非常重要。
