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LIFE MARGAL ULLA - Recovery of populations of Margaritifera margaritifera and Galemys pyrenaicus inn the Ulla river basin (Galicia) Reference: LIFE09 NAT/ES/000514 | Acronym: MARGAL ULLA
In the Ulla river basin, a variety of pressures impact negatively on aquatic species such as the freshwater pearl mussel (Margaritifera margaritifera) and the Pyrenean desman (Galemys pyrenaicus). Threats affecting these species include the degradation of river bed substrate from dredging and siltation, the deterioration of riparian forest and obstacles that make it difficult for juvenile fish from the salmonid family (which act as important hosts to M. margaritifera in their larvae stage) to move upriver.
Both the freshwater pearl mussel and the Pyrenean desman act as biological indicators for the overall state of the Ulla’s fluvial ecosystem. Conservation actions that tackle threats to these species will thus have knock-on benefits for many other species living within the Ulla river basin.
Project data:
Coordinator: XUNTA DE GALICIA. CONSELLERÍA DOMEDIO RURAL. Type of organisation; Public Enterprise Partners: Universidad de Santiago de Compostela, Spain; Aguas de Galicia, Spain Collaborator: Consellería do Medio Rural, Xunta de Galicia, Galicia, Spain.
Project reference: LIFE09 NAT/ES/000514 Duration: 01/10/2010 to 31/08/2015 Total Budget:3.666.981,00 € EU contribution: 1.821.604,00 € Project location: Galicia (España) Project Manager: Jesús SANTAMARINA FERNÁNDEZ
Project Description
Background In the Ulla river basin, a variety of pressures impact negatively on aquatic species such as the freshwater pearl mussel (Margaritifera margaritifera) and the Pyrenean desman (Galemys pyrenaicus). Threats affecting these species include the degradation of river bed substrate from dredging and siltation, the deterioration of riparian forest and obstacles that make it difficult for juvenile fish from the salmonid family (which act as important hosts to M. margaritifera in their larvae stage) to move upriver.
Both the freshwater pearl mussel and the Pyrenean desman act as biological indicators for the overall state of the Ulla’s fluvial ecosystem. Conservation actions that tackle threats to these species will thus have knock-on benefits for many other species living within the Ulla river basin.
Objectives The overall objective of MARGAL ULLA was to help improve the conservation status of the freshwater pearl mussel and Pyrenean desman in the Ulla river basin and to create suitable conditions for the recovery of existing populations. This was achieved by:
- Increasing the level of knowledge available about factors threatening both species;
- Improving habitat issues associated with the decline of both species;
- Implementing measures to recover the hydromorphology of certain sections affected by dams and drawdown flow in order to foster the natural dynamics of the freshwater pearl mussel and help connect potential desman populations; Strengthening existing populations and reintroducing M. margaritifera in suitable areas of the river basin;
- Improving the conservation status of riparian forest in the project area;
- Ensuring the implementation of best practice where the management of the river, its riparian forest habitats and river quality (e.g plants health, bedload and particles) are concerned.
Results The MARGAL ULLA project improved the ecological status of over 75 km of river in the Ulla River Basin. This was achieved by a number of actions. Firstly, nine river barriers were demolished to improve the hydrology of the river. An extensive inventory was carried out to find potential barriers and 14 were then identified. Most of these barriers were very old. Some of them still had existing rights of use even though they had not been used for decades and others were protected for heritage reasons. A decision was made to just take away barriers that weren’t protected and which did not still have existing rights of use. In addition, local opposition to the demolition of other barriers also had to be considered and meant that the number of barriers to be removed was reduced even more.
Secondly, a number of invasive alien species (IAS) were eradicated along 11 sections of the river bank (a total of 25km). In particular the species Robinia pseudoacacia, Arundo donax and Phyloostachys sp. were chopped down. Autochthonous species typical of riverine areas were then planted in 15 different areas. These included Alnus glutinosa, Fraxinus excelsior, Salix atrocinerea, Quercus robur, Betula celtiberica and Corylus avellana.
Finally, project partners limited the sources of pollution into the river – a task that proved to be much more complicated than originally thought. There are two main pollution sources affecting the target species: The first was from previous mining activity. These sites were restored during the project and the water quality has now improved. The second source of pollution, however, comes from cattle and is much more difficult to control. Training and awareness raising activities were organised for cattle breeders during the project to help mitigate this contamination in the long run.
Communication was also key to the success of the project and a lot of effort particularly went into communication with local farmers, who were probably the most difficult stakeholders. Specific dissemination and awareness raising events were organised to explain why the conservation of the projects target species is important. Initially attendance was very low so project partners decided to link the events to a formal training programme for farmers organised by the regional ministry. Farmers are obliged to attend these events in order to receive CAP funds and this approach proved much more effective with attendance increasing significantly (six seminars were organised in 2015 with 189 attendees). A manual on good practice was also produced and disseminated.
The project also hugely improved the information available about Margaritifera margaritifiera and Galemys pyrenaicus in the Ulla River Basin. Project partners mapped the main populations of both species as well as their conservation status. Their habitats were described and significant information on their characteristics was obtained. The main threats were also identified through a detailed analysis of the river’s ecological status which helped to determine the main sources of pollution. All of this knowledge was used to develop new management methods, including detailed conservation measures for the species to improve the protection of key areas. These will be incorporated into the River Basin Management Plan, the main policy instrument for the management of the project area.
The pearl mussel captive breeding programme was also a great success. Almost 30 000 juvenile mussels are now being kept in controlled conditions waiting to be reintroduced into the river (infested salmon juveniles are also regularly released). An intensive capture campaign was designed during the project specifically to catch specimens of G. pyrenaicus using a new tramping system. The success ratio in obtaining mussels seeds increased significantly after the technique was fine-tuned and in total, three breeding seasons were completed rather than just the two originally planned. This action was developed with very limited resources and without previous experience but worked extremely well thanks to great efforts from the project team and excellent collaboration with other European projects.
The beneficiaries have drawn up a detailed After-LIFE Plan to ensure the continuation of the work started in the project. This includes the continuation of the pearl mussel breeding programme which has been guaranteed finances for at least two more years. The water department is also committed to integrating the conservation measures developed within MARGAL ULLA into the River Basin Management Plan.
