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Project „Restoration of habitats of freshwater pearl mussel”

Pearlriver/Pärlijõgi river
At the beginning of the 20th century, the pearl mussel was widespread and in abundance. In Central-Europe pearl mussel populations have decreased dramatically by the end of 20th century (up to 90%), and this trend is ongoing. Now it has captured the whole European populations.

Habitat (fast-flowing cool rivers and streams) damage and loss are the main threats to the pearl mussel.

Historically widespread freshwater pearl mussel is today in Estonia present in only one river and the population there is small and decreasing. The average age of this population is 60 years and reproduction does not take place. The species is addressed as one of the rarest and most endangered animal species in Estonia.

The target of the Project
The project bases upon the action plan prepared for the protection of Freshwater Pearl Mussel (FPM) in the period of 2014–2018 and tackles most urgent practical restoration works foreseen with the action plan. The target of the project is to preserve the FPM population in the Pärlijõgi river (former Pudisoo river), it is achieved with restoration of habitats of trout and salmon, reducing sediment inflow from the catchment, minimizing the beaver population (all priority I actions). To achieve it, it is necessary to involve the local community and exchange experiences among experts. FPM is a species with long lifespan, so the project does not set an aim to increase the population or achieve successful breeding within the project frame. The aimed result are minimized population of beavers, improved waterquality and improved habitats for host species.

Project partnership
Project beneficiary is Republic of Estonia Environmental Board and the project partners are Estonian Forest Management Centre (RMK) and Norwegian Institute of Nature Research (NINA).

Roles of the Partners
Republic of Estonia Environmental Board was project coordinator and was responsible for project results achievement and for freshwater pearl mussel experts training for future conservation work in Estonia. (Republic of Estonia) Environmental Board carried out all project activities, involved local community and publicity into project, co-operated with freshwater pearl mussel experts abroad.

State Forest Management Centre (RMK) is responsible for practical nature conservation management on state owned land, ie in the current project the task of RMK is restoration of freshwater pearl mussel habitats in state owned land. The future maintenance of the restored areas on state property will be the task of RMK, that is the reason why the experts of RMK will be included in the experience exchange program planned in the frame of the project. RMK contributes to the project its specialists, who will be prepared during the Project for future freshwater pearl mussel artificial growing in Estonia and for future restoration works on state land.

The role of NINA in the frame of the project is consulting the practical restoration activities planned within the project and to provide necessary knowledge to replicate the best practice proved efficient in Norway. It is planned to involve experts from NINA to the practical actions and trainings in Estonia as well as to introduce the work done in Norway to Estonian specialists. NINA contributes the project its expertise in management of freshwater pearl mussel in Norway.

Donor partnership achievements
Through donor partnership of Norwegian Institute for Nature Research (NINA) Republic of Estonia Environmental Board specialists learned new information about freshwater pearl mussel and its natural conservation methods. Specialists’ knowledge and practical skill levels approved. At the beginning of the project, Environmental Board did not have any FPM specialists, after finishing the project however Environmental Board has at least 2 specialists and 1 expert, who are able to plan and manage FPM conservation work and artificial breeding in the future. NINA had new data about small FPM populations and practical experiences about how to work with small and old FPM populations. On the other hand, NINA also got to know Estonian natural conservation methods and could use good Estonian practices in Norway (managing of protected areas and species, co-operation with local landowners etc.).

State Forest Management Centre and Environmental Board donor partnership in this project was necessary for specialists and experts educating about freshwater pearl mussel and for the future natural conservation work projects planning. Since State Forest Management Centre has to carry out active conservation work on protected areas and for protected species, the knowledge that was learned during the project is very useful for those activities.

Summary of the Project results
1. Suitable conditions for freshwater pearl mussel (FPM) procreation are created in Pärlijõgi (former Pudisoo) river. In 15 km river line are suitable conditions for FPM – project results have revealed that FPM procreation in Pärlijõgi river is active, FPM is producing glohides and host fishes are infected with FPM larvae. In the future, it is necessary to continue improving FPM juveniles microhabitat quality, to increase survivability ratings of FPM juveniles in Pärlijõgi river.
2. As a beaver hunt result, beaver population density in Pärlijõgi river is decreased: in 2016 altogether 3 beaver broods (about 10 beavers) were living in the river.
3. Local community awareness about FPM is raised – landowners and other local community members are aware about species rareness, dangers to FPM population and why/how to protect the species. Public awareness about FPM is raised – approximately 90 people are involved indirectly (volunteers who participated in Estonian Fund for Nature work-camps, participants of FPM inventory methods workshop, participants of beaver hunt workshop) and about 30 people are involved directly (local landowners and other co-operation partners).
4. Good ecological condition of Pärlijõgi river is restored (reduced fine sediments and beavers activity impact, increased passage opportunities for FPM host fish, restored natural conditions in partly straightened river part) on 15 km river line, including FPM habitat restoration (beaver dams and other obstacles removed, wooden dams created into inflows for fine sediment pollution reducing) on 12 km river line, where mussels are present.

Duration and cost of the project: 09.07.2014- 30.04.2016; 227116,10 €.

Pärlijõgi river/Pearlriver
Photo: Kaido Haagen


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