Freshwater Pearl Mussel and its habitats (LIFE04/NAT/SE/00023)
Freshwater Pearl Mussel and its habitats (LIFE04/NAT/SE/00023)
Key features of the case study
Drivers
Main concerns: Ecological concerns
Legal requirements: Natura 2000
Opportunities: Broader management plan (Swedish national conservation plan)
95 % of the Fresh Pearl water mussel population in Central Europe has fallen. The specie is classified by IUCN as endangered and is included in the EU habitat directive. Sweden is home to a large part of the remaining population (a core area) and therefore have an international responsibility for the species’ long-term survival’.
Pressures
Hydrological regime modification
Artificial barries upstream from the site
Artificial barries downstream from the site
Alteration of instream habitats
Sedimentation and sediment input
Nutrients pollution
Micropollutants
Acidification
Humans activities
Mainly forestry
Agriculture
Global objectives
Species enhancement and habitats improvement were the main objectives of the project by developing and testing methods to achieve a favourable conservation status for the freshwater pearl mussel (Margaritifera margaritifera) in Sweden. However, freshwater mussel was not the only target specie of the project. A freshwater mussel population decrease highlights a deterioration of the environnment, the improvement of freshwater mussels habitats will thus benefit other aquatic species such as host fish.
Specific goals (process oriented)
In order to achieve the conservation of Margaritifera margaritifera, the project aimed to :
1. eliminate the migration obstacles to host fish along ten watercourses
2. improve the river bed in eight watercourses
3. manage the banks along two small rivers
4. Re-introduce young mussels (test in one stream)
Site description
Measures selection
Description
Several measures were implemented aiming to restore the Margaritifera margaritifera population using different means:
1. Water flow quantity improvement Repairing a dam that regulates the water flow into the stream Lillsjöbäcken to avoid water shortage in summer
2. Sedimnt flow quantity improvement Blocking of 17 ditches with wood and ground materials to reduce negative impact from siltation
3. Longitudinal connectivity improvement Removing obstacles Fixing incorrectly placed road culverts Building bypasses around migration obstacles
4. In-channel structure and substrate improvement Deposit of gravel and small stones in fast-flowing river sectionsn (restoration of around 1 300 m2 of stream grounds across eight sites through )
5. Riparian zone improvement Removal of spruce and other vegetation which impact on streams, in favour of deciduous trees along two shoreline sites (a total of 4.5 hectares buffer zone have been thinned and cleared along the streams Sollumsån and Bratteforsån)
6. Specie enhancement Reintroduction of freshwater pearl mussels (1 000 mussels collected from a nearby watercourse in the same basin.)
Constraints
Every measures were not implemented as foreseen due to different constraints. Some actions were actually compromised due to historic cultural values, and one action was postponed due to disagreement with landowner. Furthermore, the planned deposit of gravel was less than anticipated due to research which revealed lower need.
Success criteria
The mussel recruitment is expected within the coming 10–20 years. None measurable criteria were actually set in the frame of the LIFE project due its too short time frame. However, measurable criteria with regards to the Margaritifera margaritifera recruitment have been set in the frame of the swedish national conservation plan (XX).
Ecological response
Other biota
Due to the complex life cycle of the freshwater mussel, it will take 5-10 years (at least) before it is possible to assess the real conservation impact of the implemented actions. However, the first monitoring highlights an increase of freshwater pearl mussel larvae on the fish geals.
Hydromorphological response
Monitoring before and after implementation of the project
Before
Biotic, chemistry and hydromorphologic studies were carried before restoration in order to select suitable sites by evaluating the viability and the size of the population:
1. BOTIC: Monitoring freshwater pearl mussel and host fish. Electricfishing were carried to evaluate the host fish population (and to assess mussel larvae parasites on fish geals) and mussels inventories were done by using an Aquascope or peep box (monitoring according to the standard method recommended by the Swedish Environmental Protection Agency)
2. HYDROMORPHOLOGIC: Monitoring riverbed substrates by documenting the rate of sedimentation of riverbeds, the distribution of substrate size from silt to boulder, the turbidity of the water and the level of sedimentation (June-September)
3. WATER QUALITY (especially pH)
After
Those assessments were also carried after restoration. The post-monitoring, carried on by the County Administrative Board, still runs for the Margaritifera margaritifera population and also electric fishing. Besides, the University of Karlstad is currently monitoring the sedimentation of the river beds. Sedimentation samples were taken before and after the restoration to see whether the siltation/sedimentation has decreased. This monitoring aimed to evaluate the success and efficiency of the measures but also of the forest owners information (bad forestry management is common sources to sedimentation in streams).
Reference site
Socio-economic aspects
COOPERATION
The project involved the following partners: County Administrative Boards in the counties of Kalmar, Västmanland, Örebro and Västra Götaland, the Swedish Forest Agency, the Karlstad University and the City of Göteborg. All partners were great actors and carried out most of the fieldwork. The Forest Agency were a great resource of carrying out the knowledge improvement and information to landowners. Furthermore, the project has increased the cooperation between authorities and other actors such as NGOs and has contributed to the national Actionplan for Margatifera margatifera. All those factors are important for a long nature conservation perspective.
INTERACTION
Description and objectives
Consultation and dialogue played a key role in the project process. The fresh pearl mussel status is actually largely dependent on external factors related to land use outside and upstream of the mussel sites. Therefore, the project managers wished to actively involve stakeholders (mainly forestry owners and other landowners) aiming to increase their awareness which could lead to change of practices.
Goals achievement
Those changes and their related effects cannot be evaluated in a short term but must be assessed in a long term perspective. An increase of knowledge about aquatic conservation will obviously lead to the consideration and the respect of forest streams. Nevertheless, some local changes were noticed such as wider bufferzone along the water, use of temporary bridges when driving the machines etc. Project managers still persuades forest owners to integrate water ressources management in the forest planning in order to protect sensitive areas and valuable habitats.
COMMUNICATION
Description and objectives
Information and education were also part of the project focusing on several audiences such as public, restoration practitionners, forestry owners and others landowners. The objectives were mainly to increase the knowledge and consideration of the aquatic conservation within the forest sector and to collect all the experiences and knowledge in a manual.
Efforts were thus devoted to education by the following means:
1. Seminars and conferences such as the “Aquatic Conservation with Focus on the freshwater pearl mussel Margaritifera margaritifera” held on August 12–14, 2009
2. Several information materials such as brochures, field signs, home page, poster and a film
3. A manual that summarizes the project practical experiences in order to share and increase restoration knowledges “Restoration of freshwater pearl mussel Streams” (Degerman et al., 2009)
Goals achievement
The project has improved the knowledge and understanding for aquatic conservation The conference allowed a great knowledge exchange between several experts and succeed by building a national and international network around aquatic conservation (especially for Margaritifera margaritifera). The swedish experience and knowledges, summarized in the manual, is now shared and used in several countries. The manual has successfully been communicated and is currently used both as a practical tool for planning restoration work and also as an inspiration for aquatic conservation. Nevertheless, project managers must be aware that communication and information is a constantly ongoing action.
OTHERS FEEDBACKS/ LEARNINGS
Inputs of LIFE/INTERREG
LIFE helped the project managers to implement a broad range of measures by making a large amount of money quickly available but also by giving access to a large network (contacts with other LIFE Nature projects). On the other hand, the LIFE bureaucracy led to a heavy administrative part,
Project improvements
Limits faced
The timeframe of the project seemed to be too short. The success of the Margaritifera margaritifera enhancement can not be evaluated yet. It will take at least 5-10 years before the specie will recover.
Others lessons
The importance of gathering all the actors/stakholders of the catchment area and create an interaction with them
The importance of information and education of actors within landuse (mainly foresty)
The importance th have an agreement and dialog with the landowners,
Remember to document and save all photos and monitoring information
Good with a detailed action plan
Follow-Up
The Margatifera margatifera conservation continues through the national swedish conservation plan. The LIFE project actually added lots of technical, scientific inputs in this broader management plan.
Contact person within the organization
Contact_Name Sofi Alexanderson Contact role Project manager/coordinator Contacts_OrganisationName WWF Contacts_OrganisationType NGO-Foundation Contact_Phone-Number 00 466247449 Contact_Email sofi.alexanderson@wwf.se
Extra background information
Restoration of freshwater pearl mussel Streams (Degerman et al., 2009): http://www.wwf.se/source.php/1257735/Restoration%20of%20FPM%20streams.pdf)
National conservation plan : http://www.naturvardsverket.se/Documents/publikationer/620-5429-5.pdf (swedish)
References
Website1 http://www.wwf.se/vrt-arbete/stvattenvtmarker/flodprlmussla/1127105-flodprlmusslan Website2 www.wwf.se/fpm LIFE Web Summary http://ec.europa.eu/environment/life/project/Projects/index.cfm?fuseaction=search.dspPage&n_proj_id2616&docType=pdf
LIFE Layman’s report http://www.wwf.se/source.php/1268431/Freshwater_pearl_mussel.pdf
Related Measures
- Remove barrier
- Narrow water courses
- Improve/Create water storage
- Reduce undesired sediment input
- Install fish pass/bypass/side channel for upstream migration
- Modify culverts, syphons, piped streams
- Develop riparian forest
