计算毒理学和暴露中心Michael B. Mahon课题组近日取得一项新成果。经过不懈努力，他们报道了冷暖河川鱼类生物多样性分化趋势。这一研究成果发表在2025年9月24日出版的国际学术期刊《自然》上。

在这里，课题组人员协调了美国联邦生物监测数据集，其中包括27年（1993-2019）的389个物种和2992个地点，以分析鱼类生物多样性的趋势。在寒冷的河流(过去的夏季河流温度低于15.4°C)，鱼类丰度和丰富度在27年间分别下降了53.4%和32%，独特性增加。周期性（大体型、晚熟）鱼类数量增加，而机会型（小体型、代时间短、“r选择”）鱼类数量减少，这可能是由于本地或引进的猎用鱼数量激增所致。在温暖的溪流中(溪流温度高于23.8°C)，鱼类丰度和丰富度在27年间分别增加了70.5%和15.6%，群落均质化。小型机会性鱼类取代了大型周期性鱼类。中间溪流(溪流温度15.4-23.8 °C)，代表平均流，随着时间的推移，鱼类生物多样性的变化很小。变暖和引进鱼类之间的相互作用与当地鱼类生物多样性退化率的增加有关。鉴于这些变化在相对较短的时间跨度内的规模，迫切需要遏制鱼类引入和水温升高引起的鱼类生物多样性退化。

据介绍，在世界范围内，淡水系统包含超过18,000种鱼类，这些鱼类对这些生态系统的功能至关重要，也是人类重要的文化和经济资源；尽管如此，鱼类生物多样性在全球范围内仍处于危险之中。在美国，河流和溪流中鱼类群落面临的主要威胁包括气候变化、入侵性鱼类引进和人类放养的鱼类。

附：英文原文

Title: Diverging fish biodiversity trends in cold and warm rivers and streams

Author: Rumschlag, Samantha L., Gallagher, Brian, Hill, Ryan, Schfer, Ralf B., Schmidt, Travis S., Woods, Taylor, Kopp, Darin, Dumelle, Michael, Rohr, Jason R., De Laender, Frederik, Hoffman, Joel, Behrens, Jonathan, Lepak, Ryan, Jones, Devin K., Mahon, Michael B.

Issue&Volume: 2025-09-24

Abstract: Worldwide, freshwater systems contain more than 18,000 fish species1,2,3, which are critical to the functioning of these ecosystems4 and are vital cultural and economic resources to humans5,6,7; despite this value, fish biodiversity is at risk globally8,9. In the USA, leading threats to fish communities in rivers and streams include climate change and invasive fish introductions and game fish stocking by humans10,11,12,13,14. Here we harmonized US federal biomonitoring datasets with 389 species spanning 27 years (1993–2019) and 2,992 sites to analyse trends in fish biodiversity. In cold streams (past summer stream temperatures below 15.4°C), fish abundance and richness declined by 53.4% and 32% over 27 years, respectively, and uniqueness increased. Periodic (large-bodied, late-maturing) fishes increased, and opportunists (small-bodied, short generation time, ‘r-selected’) decreased, possibly due to proliferation of native or introduced game fishes. In warm streams (stream temperatures greater than 23.8°C), fish abundance and richness increased by 70.5% and 15.6% over 27 years, respectively, and communities homogenized. Small opportunistic fishes replaced large periodic fishes. Intermediate streams (stream temperatures 15.4–23.8°C), representing the average stream, had minimal changes in fish biodiversity through time. Interactions between warming and introduced fish were associated with increased rates of degradation to local fish biodiversity. Given the magnitude of these changes in a relatively short time span, there is an urgent need to curb degradation of fish biodiversity caused by fish introductions and warming water temperatures.

DOI: 10.1038/s41586-025-09556-0

Source: https://www.nature.com/articles/s41586-025-09556-0