Institute of Life, Earth and Environment (ILEE), Research Unit in Environmental and Evolutionary Biology (URBE), rue de Bruxelles 61, Namur B-5000, Belgium.
Profish Technology, 18, rue des scabieuses, Naninne 5100, Belgium.
Comp Biochem Physiol A Mol Integr Physiol. 2021 Apr;254:110876. doi: 10.1016/j.cbpa.2020.110876. Epub 2020 Dec 20.
Hydropower plants (HPPs) are a source of "green" energy but also a threat to migrating fish such as the European eel (Anguilla anguilla) owing to the disruption of river connectivity and the obstruction of downstream migration. The impact of HPP are well-documented in terms of fish survival and damages but there is no available information concerning the condition of surviving and unharmed fish. The aim of this study is to assess the impact of the passage through HPP on the survival, the physiological and health status of adult eels. Two trials were carried with variants of the Kaplan turbine - one of the most common types in Europe. After a deliberate passage through the turbines, we studied direct mortality, external and internal damages, stress and immune biomarkers such as plasma cortisol and glucose levels, alternative complement (ACH50), lysozyme and peroxidase activities, and total immunoglobulin (Ig) content. Our results showed a lower survival and a higher external and internal damages rates in the HPP groups. Glucose levels, ACH50, lysozyme and peroxidase activities and TIgc were also affected by the passage depending on HPP characteristics. Those findings suggest a greater energy expenditure and a disruption in innate immunity due to this passage. HPPs can not only have an impact in terms of direct mortality and injuries but also affect the physiological and health condition of the surviving eels. This impact may explain the delayed mortality observed in telemetric studies and the passage through many HPPs may compromise the ability of adult eels to migrate successfully to the ocean.
水力发电站（HPP）是一种“绿色”能源，但也对洄游鱼类（如欧鳗 Anguilla anguilla）构成威胁，因为这会破坏河流的连通性并阻碍下游洄游。关于鱼类的生存和损害，HPP 的影响已有充分的记录，但对于幸存和未受伤害的鱼类的状况，尚无可用信息。本研究旨在评估鱼类通过 HPP 对成年鳗鱼的生存、生理和健康状况的影响。本研究进行了两次试验，使用了欧洲最常见的涡轮机之一——卡普兰涡轮机的变体。在故意通过涡轮机后，我们研究了直接死亡率、外部和内部损伤、应激和免疫生物标志物，如血浆皮质醇和葡萄糖水平、替代补体（ACH50）、溶菌酶和过氧化物酶活性以及总免疫球蛋白（Ig）含量。我们的研究结果表明，在 HPP 组中，鳗鱼的存活率较低，外部和内部损伤率较高。葡萄糖水平、ACH50、溶菌酶和过氧化物酶活性以及 TIgc 也因 HPP 的特征而受到通过的影响。这些发现表明，由于这种通过，鳗鱼的能量消耗增加，先天免疫受到破坏。HPP 不仅会直接导致死亡率和伤害，还会影响幸存鳗鱼的生理和健康状况。这种影响可能解释了遥测研究中观察到的延迟死亡率，以及通过多个 HPP 可能会削弱成年鳗鱼成功洄游到海洋的能力。
