PROJECT DESCRIPTION
BACKGROUND
The European sturgeon (Acipenser sturio) is one of the five priority fish species listed in Directive 92/43/EEC. Once found throughout the seas and great rivers of Europe, this migratory species is now on the brink of extinction as a result of the degradation of water courses and intensive fishing. The Gironde-Dordogne-Garonne catchment has the last breeding area known to be left in the world. A previous LIFE project for this species has already allowed the various key sites in the catchment, such as spawning areas and foraging areas for juveniles, to be identified, as well as the impact of fishing in the estuary. This project also succeeded in 1995 in carrying out the first-ever breeding in captivity. Some of this offspring was subsequently released in the wild.
OBJECTIVES
Based on the results of its predecessor, this project aimed at concentrating its efforts on those measures which are crucial to the species survival. It was planned to:
Improve the conditions of captive breeding, in order to have a breeding stock sufficient to ensure regular reproduction for release purposes. Carry out information campaigns towards fishermen to restrict mortality due to accidental catches. Negociate management prescriptions for the sturgeon and its habitats with users, socio-economic interest groups and local stakeholders, in order to come to effective conservation measures. Elaborate a strategy for sturgeon recovery at the Union level, in collaboration with a network of partners abroad.
RESULTS
Although the status of the species has not improved, the project still managed to:
Improve the knowledge of the species, its habitats, its diet and the dynamic of its populations; the studies carried out by the project confirmed and refined the results of the previous project on the identification of area occupied by juveniles and on the sturgeon diet. They have also permit to define concrete management and protection measures to be integrated in the future management plan of the Natura 2000 site. Limitate mortality cases through accidental captures in the sea, in the estuary and in the river: a survey of 2500 fishing ships and of professional fishing organisations in the whole Atlantic area has been carried out and information materials giving advices on how to behave in case of an accidental capture was distributed. The project has also revealed that, on the short term, the main threat was poaching. Therefore, training of agents in charge of the fishing surveillance was organised. Prevent the threat relative to the accidental introduction of Acipenser baeri in the wild: 27 tonnes (representing approximately 8000 individuals) of Siberian sturgeon (Acipenser baeri) were accidentally released from a private farm in the Gironde estuary during the December 1999 storm. Only 7 tonnes (1045 fishes) were recaptured during the following weeks and it was estimated that 3200 fishes spread over the Gironde catchment. The major risks of accidental introductions of exotic species are diseases, food and habitat competition and hybridisation. To limit such threats, several actions were carried out though not planned at the beginning: capture of escaped fishes, monitoring and evaluation of the species dissemination risk, elaboration of an identification sheet to avoid mixing-up both species and study of the A. baeri's diet to estimate competition risks. Carry out awareness actions: two main campaigns were carried out targeting citizens and fishermen. 285 posters (4x3 m) were displayed in the main cities of the west of France and 5000 stickers "SOS sturgeon" were distributed. A press pack was also published in the main regional newspaper (550 000 readers). Unfortunately, some results could not be achieved despite the effort done during the project. Indeed, It was planned to develop some artificial food and to produce alevins in the breeding centre in order to plan reintroduction in the wild. Works were carried out as planned but they did not allowed the full understanding of the Sturio's diet needs, nor the deformities observed in captivity. The species
Accipenser baeri, serving as model for the study, is far less sensitive than the sturio and the captive stock of sturio were too scarce to allow direct experimentation on this species. Studies on that subject have carried on after the project. Concerning reproduction, the results are also poor, mainly because of a lack of captive adult females . Moreover, the difficulties in breeding this species have not been solved during the project despite efforts made. Monitoring of the population as well as action results were also carried out. The situation of the sturio has been judged worrying and the population in such at threat that restoration measures are required. In 2001, the population amounted for around 4000 individuals with 300 dying accidentally each year. The latest species reproductions occurred in 1994 in the wild and in 1995 in the breeding centre. Moreover, the captive stock is decreasing, and even if breeding techniques are improving, chances of obtaining an artificial reproduction are weak. A European network was established during the project gathering various institutions and NGOs (the French ministry of environment, UICN, WWF, Ramsar…) in order to carry on actions for this highly threatened species following the LIFE–project.
