The distribution of asp (Leuciscus aspius) in Sweden is limited and primarily associated with water bodies in the Mälardalen, Emån, Dalälven, Lake Vänern, the Göta River, and the Motala Ström water system. Previous surveys have confirmed the presence of the species in the Gullspång River, but whether stable spawning occurs in the system has remained unclear. On behalf of Fortum, an eDNA survey of the fish fauna in the Gullspång River was conducted, with a particular focus on asp during its spawning period. The study aimed to map the species’ distribution and identify potential spawning sites to better understand its ecology and reproductive success.
The results of the study showed a high detection rate of asp at several surveyed locations, indicating that the species is present in the river during the spawning period. A total of 19 fish species were identified, including salmon (Salmo salar) and brown trout (Salmo trutta), which were commonly detected, confirming that the Gullspång River continues to serve as an important reproduction area for several migratory species. The survey also demonstrated that eDNA is a highly sensitive and effective method for detecting species in running waters, enabling more detailed and non-invasive monitoring of fish populations.
The collected data can be used to guide further targeted surveys at locations with high asp detection rates to clarify the species’ spawning success and habitat preferences. This study provides a valuable foundation for future conservation efforts and management programs and can contribute to ensuring long-term monitoring and sustainable management of the asp population in the Gullspång River.
