Fish community turnover in a dammed Andean River over time

ABSTRACT We describe the change in fish community of Porce River Magdalena Basin, Colombia, following construction III hydropower reservoir based on 13 years monitoring data. The results show a clear reduction number native species, which have been supplanted by colonizing non-native especially reservoir. Four species detected prior to dam apparently disappeared, but 12 new were registered post-construction. analyzed spatial changes beta diversity aquatic environments surrounding dam. environment generated presents unique composition and contributes significantly total system. Altogether three distinct assemblages emerged formation there are now six where had previously three. This dramatic change, already visible within decade construction, highlights just how strong an impact has habitats rapidly communities react this hotspot for endemic diversity. Our findings demonstrate importance revealing damming river ecosystems informs potential complementary inventories elsewhere basin.