A Tale of Three Rivers: An investigation into fish biodiversity and water quality in three rivers in southern Sweden

Sammanfattning

Riverine biodiversity is affected by anthropogenic activities through increased environmental and chemical pollution. This paper attemps to examine if fluctuation in water chemistry in closely located sites of similar water quality are also correlated to changes in fish biodiversity and community composition. This study focused on the Vramsån, Vinneå, and Mjöån in Southern Sweden. Fiver years of water quality data was examined and compared with eDNA raw data report from May 2025 as reported by MIX Research. Water quality varied between the three rivers. Biodiversity did not vary significantly between rivers. The highest alpha diversity was found at the furthest downstream sites for each river. There was no clear correlation between water chemistries studied and biodiversity. Furhter funding and studies are needed for European river preservation and restoration to understand the risk of continued biodiversity loss and what factors may influence it including water quality, sedimentation, and pollution (including agricultaral runoff, PFAS, heavy metals, and pharmaceuticals).