Keys to a successful reintroduction of the only in Spain

Nine unique species in the natural heritage españolEspaña is the EU country's most biodiverse, but half of the species are amenazadasReservas for insects: wher

Keys to a successful reintroduction of the only in Spain
Nine unique species in the natural heritage españolEspaña is the EU country's most biodiverse, but half of the species are amenazadasReservas for insects: where they are and why they are important

The only or sturgeon (Acipenser sturio) has always been considered a fish iconic of our rivers and coasts. Today, however, there are no populations of this species in Spain as a result of a rapid regression took place during the second half of the TWENTIETH century. A project, coordinated by the Foundation Conde Salazar, from the Escuela Técnica Superior de Ingeniería de Montes, Forestal, and Natural Environment of the Polytechnic University of Madrid (UPM), has been studied, precisely, the feasibility of the reintroduction of the only in the Guadalquivir, the Guadiana and the Minho.

From the technical point of view, the basin of the Miño-Sil , a priori, seems to be the most suitable, since there is an abundance of areas of river natural, and booked potential desovaderos . "It is important to highlight, also, their greater proximity to the Gironde estuary (France), where it resists the last wild population of only, and to the basins of the Garonne and the Dordogne (France), chosen for releasing specimens bred in captivity", says one of the experts who collaborated on the project ONLY, Clive Dove.

For this researcher, the recovery of the species in Spain requires, in the first place, the introduction of a conservation programme that guides your actions towards the protection of critical locations for spawning and feeding only, for example. As well as supporting your reintroduction in the natural environment thanks to the joint efforts of the administrations, research centres and commercial farms of sturgeons. Of course, in his opinion, it would also have to monitor constantly to the released individuals, to prevent poaching, and recapture them from time to time, in order to assess the success of the initiative. "Only the sum of the frameworks european, national and regional appropriate, the financial resources needed, the social support , the scientific potential that we possess and the degree of technological development that has reached the fish " allow re-observed sollos on the slopes of the cantabrian, atlantic and mediterranean, underlines the Dove.

different stages of The complex life cycle only develop in the river, the estuary and the sea

"You should create at least two facilities (or breeding stock) in Spain to overcome adversities such as episodes pathological , flood , glitches or pollution of aquifers, which, although rare, can not be completely eliminated", he says.

incidental Catches in Galica

Both in 2017 as a 2018 have been identified incidental catches of only in the waters of corunna. In the first case it was a juvenile released in 2010 in the framework of the above programme of conservation French of the species, operating from four decades ago. The second sturgeon, in return, he had to dial and place a microchip. In this way, the researchers rely on to increase the "not yet well-defined details" of your biology from the data collected.

The only, by your late sexual maturation and its size, is very vulnerable to modifications of their habitat

"Given the surface and location of marine protected areas within the european network Natura 2000 , both in Galicia and in the rest of Spanish territory, and French is plausible to pose a connectivity of habitats only between southwestern France and the bay of Biscay," notes Dove. The National Strategy of River Restoration has also removed "half a hundred obstacles, such as dams and weirs of different size, in the slope of the cantabrian during the last decade, added the researcher.

In April, the Ministry for the Ecological Transition, which supports, in addition, the project ONLY through the Biodiversity Foundation, signed an agreement by which France ceded to Spain sturgeons for work of "raising awareness". The agreement, as confirmed from the UPM, and could be expanded and include copies to be loose and experimental in 2019 within another program: the Life+ Migratoebre , who works in the area of the mediterranean, where it has also been noted the historical presence of the species.

Updated Date: 11 September 2019, 23:01

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