At the beginning of June, the first surveys of the protected freshwater pearl mussel were carried out in the Likan and Fämtan Rivers in Värmland. Although no mussels were found this time, the surveys provided important knowledge – and hope for the mussel remains alive.
First step towards new knowledge about the freshwater pearl mussel
Over two days, seven dedicated participants searched for Freshwater pearl mussels in the Likan and Fämtan rivers in northern Värmland. With aquascopes, flashlights – and in some cases snorkels and masks – the lower parts of the systems were searched for the rare species. Although no mussels were found this time, the effort was far from in vain.
– “We are pleased that the project is now underway and that we have started the first inventories of freshwater pearl mussel in Likan and Fämtan,” says Sandra Woronin, project manager for Improve Aquatic LIFE and coordinator at the county administrative board in Värmland.
Mussel inventory with snorkel and mask.
Photo: Sandra Woronin
An ecosystem with potential
It is already known that the Freshwater pearl mussel occurs further up the Klarälven water system, on the Norwegian side in Trysilelva. However, the larger Swedish tributaries have never been fully inventoried before, making this year’s work an important milestone. Since both salmon and trout – which can act as host fish for the mussel’s larvae – are found in Likan and Fämtan, hopes that the mussel can also be found here are well-founded.
As the freshwater pearl mussel is found higher up in the system of Klarälven, there is a good possibility that it could also be found in the larger tributaries.
Valuable insights
Despite the lack of mussels this time, the inventories provided important knowledge that forms a valuable basis for further work within the Improve Aquatic LIFE project, where the Freshwater pearl mussel is a priority target species.
– As the Freshwater pearl mussel is found higher up in the Klarälv system, there is a good chance that it could also be found in the larger tributaries. So far, only the lower parts closest to the Klarälven have been surveyed and although no mussels have been found yet, there are still large areas left to explore. And in addition to the inventory results, the surveys also provide valuable information about the substrate, flow conditions and surrounding environment , notes Sandra Woronin.
The seabed is being carefully examined.
Photo: Sandra Woronin
Restoration for the future of habitats
Both the Likan and Fämtan rivers have been affected by past log drivning and other human impacts. Therefore, several restoration actions are planned for the future – including removing migration barriers, restoring floodplains and re-wetting wetlands. These measures will improve habitats for both fish and mussels, and restore the ecological connectivity of the systems.
In the fall, work will continue with inventories further up the rivers. With more knowledge about the environments and continued commitment, there is a good chance that the possible presence of Freshwater pearl mussel in River can soon be confirmed.