With the collaboration of the Spanish Foundation for Biodiversity, the Charter Provincial Council of Gipuzkoa and the Basque Water Agency (URA), the AZTI-Tecnalia R+D Centre will be studying the re-stocking of the three eel phases (elver, large elver and eel) over the months of May, June and July, respectively, in three streams of the Oria basin. This joint initiative aims to gather the information needed to be able to manage the species and thus contribute to the conservation goals established in the "Management Plan for European Eel of the Autonomous Community of the Basque Country (region)" approved by the European Commission on 1 October 2010.
The studies carried out will enable the survival and growth of these three phases of the European eel to be verified so that tools geared towards the implementation of the plans to recover the species can be developed and applied. In addition to re-stocking, the project will enhance the information on the situation of the elver phase, it will estimate the escapement of the silver eel as well as the mortality caused by hydroelectric installations during the reproduction phase, and will also calculate how much of the Oria basin surface corresponds to wetlands.
Even though the study will take place in a pilot basin (that of the Oria), the information, methodologies, tools and proposals that are developed will potentially be applicable in other basins in the area where the species is distributed, in particular in those of the north of Spain, since they share very similar features with the basins in the pilot project.
A species of great interest
The European eel, the scientific name of which is Anguilla anguilla, is a peculiar species from a biological point of view, of great scientific interest and with a great fishing tradition in many zones of its distribution area, including the Basque Country. Present in nearly all of Europe and North Africa, most of its growth takes place in fresh water and it spawns in the Sargasso Sea.
Eel stocks have undergone a sharp decline throughout Europe over the last few decades as a result of the accumulation of different factors: loss and alteration of its habitats, contamination, obstacles preventing its movement in rivers, overfishing, oceanographic changes, and diseases and parasites.