River Rönne å

River Rönne å is located in the western part of Skåne and flows into Skälderviken in the Kattegat. The river is Skåne’s second largest watercourse with a catchment area of 1 890 km² and a length of 83 kilometers. Two kilometers of the river have Natura 2000 status, and a further 19 kilometers are proposed as a new Natura 2000 site, including 15 kilometers of the tributary Bäljane å. In addition, 13 kilometers of two other tributaries of River Rönne å have Natura 2000 status.

River Rönne å has a rich fish fauna with 17 known species, including salmon, sea lamprey and river lamprey,

Rich fish fauna, birds and bats
River Rönne å has a rich fish fauna with 17 known species, including salmon, sea lamprey and river lamprey, which are priority species in the project. The river is also one of Sweden’s most important watercourses for the critically endangered European eel. The river contains weak populations of the threatened large mussels, the pearl mussel and the thick-shelled mussel. The area is also of high value for terrestrial fauna and flora, especially birds such as the white-tailed godwit, kingfisher, lesser spotted woodpecker and common tern. Mammals observed include several bat species and otters.

Obstacles in the water
The river flows from Ringsjöarna through an agricultural landscape with deciduous forest to Skälderviken. At Klippan, about 38 kilometers from the coast, the hydromorphology changes, and the river changes from calm flowing to more flowing with several rapids. The rapids have been exploited by humans and for a long time hydroelectric power has been produced at several power stations. This has meant that migratory fish species have been prevented from reaching their spawning grounds in the upper parts of River Rönne å and that sediment, animals and plants have not been transported down to the sea from the Ring Lakes and tributaries along the river. The LIFE CONNECTS project will remove the three remaining hydropower plants in River Rönne å’s main channel, which means that migratory fish species and other animals will have free access to the upper parts of the river.

Restoration improves habitats
In Improve Aquatic LIFE, habitats will be restored where they have historically been cleared and straightened. By recreating more natural habitats, the project’s target species and many other species will benefit. Sea lamprey and river lamprey habitats will be restored downstream from spawning areas, as physical changes to the waterways have reduced the availability of such habitats. These species require both flowing and slack water environments, which provide spawning and nursery areas respectively. The availability of calm-flowing areas is currently in short supply and the project will therefore restore rearing habitats for lamprey downstream of the more flowing spawning areas.

In addition, floodplains will be reactivated to restore a more natural hydrology. The result will be improved water quality, reduced nutrient transport and a better ability to cope with the effects of climate change on water flows.

Host fish help mussels
Both the pearl mussel and the thick-shelled mussel depend on host fish to reproduce. To improve the survival of the species, host fish infected with mussel larvae will be released into various water bodies. For example, the pearl mussel population in the Klingstorpabäcken tributary, which currently does not have a functioning breeding population, may benefit from this measure.

Strategically working on habitat restoration, hydrological restoration and increased connectivity will significantly improve hydrology, habitat quality, biodiversity and fish production. It will improve fish and mussel habitats and contribute to an improved conservation status of both habitats and species.