The Gullspång River is home to one of the few naturally reproducing populations of wild freshwater Atlantic salmon (Salmo salar), which is of significant conservation value both nationally and internationally. To assess the status and distribution of this population, MIX Research Sweden AB conducted an eDNA survey of the fish fauna in the Gullspång River on behalf of Fortum. The study aimed to identify the presence of the Gullspång salmon and provide a more comprehensive understanding of the ecosystem’s composition.
The survey covered 13 sampling locations, with results showing salmon detections at 11 out of 13 sites, confirming the species’ continued presence and reproductive potential in the river. A total of 19 fish species were identified, with brown trout (Salmo trutta) being the most frequently detected species, further highlighting the river’s importance as a spawning and nursery habitat for migratory fish. In addition to salmon and trout, red-listed species such as European eel (Anguilla anguilla) and burbot (Lota lota) were documented, along with species covered by conservation action plans, including vimba bream (Vimba vimba) and ide (Leuciscus idus).
The results demonstrate that eDNA is a powerful and non-invasive method for assessing biodiversity in running waters, enabling large-scale surveys with high precision. This study provides crucial information for future conservation efforts, where regular monitoring can ensure that appropriate measures are taken to protect the habitat and long-term survival of the Gullspång salmon. The collected data can serve as a foundation for targeted restoration actions and management decisions aimed at strengthening ecosystem functionality and preserving threatened and protected species in the Gullspång River.
