Improving the conservation status of target species

Purpose
Three of the project’s target species have a poor conservation status and without measures these species risk becoming extinct in Sweden. The sea lamprey has declined drastically over a long period of time and today reproduction occurs in only a few watercourses in southern Sweden. The two mussel species, the pearl mussel and the thick-shelled mussel, are dependent on host fish for their reproduction. Due to migration barriers and loss of habitat for mussels and their host fish, many mussel populations are unable to reproduce properly. By creating special habitats for sea lamprey, known as backwaters and sediment banks, and infesting host fish with mussel larvae, we will improve the conservation status of these species.

Objective
The objective is to create backwaters (sediment banks) in Vramsån, Kävlingeån, Bråån, Råån, Rönne å and Ätran to improve the habitats for sea lamprey. It is unclear whether they are present in more rivers and whether there is successful reproduction. Therefore, e-DNA will be used to investigate whether there are conditions for reproduction in more watercourses along the west coast.

The aim for the mussels is to infest host fish with mussel larvae in 17 water bodies where they are present today. In this way, we can help reproduction in these rivers. Together with the removal of migration barriers and restoration of habitats, these measures will help improve the conservation status of the pearl mussel and the thick-shelled mussel.

More info to come.