Jones Peter E, Svendsen Jon C, Börger Luca, Champneys Toby, Consuegra Sofia, Jones Joshua A H, Garcia de Leaniz Carlos
Centre for Sustainable Aquatic Research (CSAR), Department of Biosciences, Swansea University, Singleton Campus, Swansea SA2 8PP, UK.
National Institute of Aquatic Resources (DTU-Aqua), Technical University of Denmark, Kemitorvet, Building 201, DK-2800 Kongens Lyngby, Denmark.
Conserv Physiol. 2020 Dec 30;8(1):coaa126. doi: 10.1093/conphys/coaa126. eCollection 2020.
Artificial barriers cause widespread impacts on freshwater fish. Swimming performance is often used as the key metric in assessing fishes' responses to river barriers. However, barrier mitigation is generally based on the swimming ability of salmonids and other strong swimmers because knowledge of swimming ability for most other freshwater fish is poor. Also, fish pass designs tend to adopt a 'one size fits all' approach because little is known about population or individual variability in swimming performance. Here, we assessed interspecific and intraspecific differences in the sustained swimming speed ( ) of five freshwater fish with contrasting body sizes, morphologies and swimming modes: topmouth gudgeon, European minnow, stone loach, bullhead and brown trout. Significant variation was identified at three organizational levels: species, populations and individual. Interspecific differences in were as large as 64 cm s, upstream populations of brown trout showed mean 27 cm s higher than downstream populations, and species exhibited high individual variation (e.g. = 62% in European minnow). Sustained swimming speed ( ) increased significantly with body size in topmouth gudgeon, European minnow and brown trout, but not in the two benthic species, bullhead and stone loach. Aerobic scope had a significant positive effect on in European minnow, stone loach and brown trout. Sustained swimming speed ( ) decreased with relative pectoral fin length in European minnow and brown trout, whereas body fineness was the best predictor in stone loach and bullhead. Hence, swimming performance correlated with a diverse range of traits that are rarely considered when predicting fish passage. Our study highlights the dangers of using species' average swimming speeds and illustrates why a 'one size fits all' approach often fails to mitigate for barrier effects. We call for an evidence-based approach to barrier mitigation, one that recognizes natural variability at multiple hierarchical levels.
人工障碍物对淡水鱼造成了广泛影响。游泳能力通常被用作评估鱼类对河流障碍物反应的关键指标。然而，障碍物缓解措施一般是基于鲑科鱼类和其他游泳能力强的鱼类的游泳能力制定的，因为对于大多数其他淡水鱼的游泳能力了解甚少。此外，鱼类通道设计往往采用“一刀切”的方法，因为对于游泳能力的种群或个体差异知之甚少。在此，我们评估了五种具有不同体型、形态和游泳模式的淡水鱼——高体鳑鲏、欧洲 minnows、石爬鮡、杜父鱼和褐鳟——的持续游泳速度（ ）的种间和种内差异。在三个组织水平上发现了显著差异：物种、种群和个体。种间差异高达 64 厘米/秒，褐鳟的上游种群平均持续游泳速度比下游种群高 27 厘米/秒，并且物种表现出较高的个体差异（例如欧洲 minnows 中变异系数 = 62%）。在高体鳑鲏、欧洲 minnows 和褐鳟中，持续游泳速度（ ）随体型显著增加，但在两种底栖鱼类杜父鱼和石爬鮡中并非如此。有氧代谢范围对欧洲 minnows、石爬鮡和褐鳟的持续游泳速度有显著的正向影响。在欧洲 minnows 和褐鳟中，持续游泳速度（ ）随相对胸鳍长度的增加而降低，而在石爬鮡和杜父鱼中，身体细长程度是最佳预测指标。因此，游泳能力与一系列在预测鱼类通道时很少考虑的特征相关。我们的研究强调了使用物种平均游泳速度的危险性，并说明了为什么“一刀切”的方法往往无法减轻障碍物的影响。我们呼吁采用基于证据的障碍物缓解方法，这种方法要认识到多个层次水平上的自然变异性。
