In recent decades, the number of alien species in Navarre has tripled: Spain

“In recent decades, the number of invasive species in Navarre has tripled”. This is the warning of Rafael Miranda, lecturer at the Zoology and Ecology Department of the University of Navarra and member of the Iberian Ichthyology Society, launched in collaboration between the University and other research centres in Spain and Portugal.

The main objective of the Society and the study of the conservation of autochthonous species in continental aquatic ecosystems: rivers, lagoons and estuaries, in Spain and Portugal. In concrete, the experts involved are focusing on endemic freshwater species - euryhalines and diadromes – fish that can live in both fresh and salty water (such as salmon and eels).

In this sense, it is striving to increase awareness of and interest in autochthonous fish species under threat due to a number of factors. Amongst the most serious, points out Mr Miranda, is the alteration of the habitat caused by hydraulic works, water extraction, industrial waste dumping, the extraction of sand or the canalisation of riverbeds. “Moreover, particularly serious is the introduction of alien species, which causes the greatest impact”, he stressed.

According to the expert, invasive fish fed into our lakes and rivers put the survival of autochthonous Iberian Ichthyofauna in danger: “In fact, biological invasions are the second great cause of loss of biodiversity in the world, being especially damaging to freshwater systems”. This is the case of predatory species such as black bass, pike or catfish, all of which are present in rivers in Navarre. (read more)