''In the last few decades, the number of exotic species in Navarre has increased threefold, issue ''.
The department of Zoology and Ecology of the University of Navarra collaborates with the Iberian Society of Ichthyology in the conservation of native fishes.
"In the last decades, the issue of exotic species in Navarra has multiplied by three". So warns Rafael Miranda, professor of the department of Zoology and Ecology of the School of Sciences of the University of Navarra and member of the Iberian Society of Ichthyology, launched with the partnership of the academic center and other centers and researchers from Spain and Portugal.
The main goal of the Society is the study and conservation of native fishes of continental aquatic ecosystems: rivers, lagoons and estuaries of Spain and Portugal. Specifically, its experts focus on endemic freshwater species, euryhalines and diadromous -fishes that can live in fresh and salt water, such as salmon and eels-.
In this sense, he works to increase the knowledge and interest in native fish threatened by various factors. Among the most serious, Rafael Miranda points out the alteration of the habitat due to hydraulic works, water extraction, industrial waste dumping, aggregate extraction or channelization of watercourses. "In addition, the introduction of exotic species, which cause the greatest impact, is particularly serious," he stresses.
According to the expert, exotic fish released into our lakes and rivers endanger the survival of the native Iberian ichthyofauna: "In fact, biological invasions are the second leading cause of biodiversity loss in the world, being especially harmful in freshwater systems". This is the case of predatory species such as black bass (or American perch), pike or catfish, all of which are present in Navarre's rivers.
The middle and lower stretches of Navarre's rivers, colonized
Likewise, the researcher of the University of Navarra -treasurer of the new Iberian Society of Ichthyology- stresses that there are other species that do not have such visible effects but can cause very serious damage to similar native fish, with which they compete for food or habitat: "This is the case of the alburno -possibly introduced as live bait from France- which in 20 years has become the dominant species in all the middle and lower stretches of the Ebro basin and which, by competing with the madrilla, has caused the latter to plummet throughout the area."
As a result, Rafael Miranda recalls that invasive fish species "have already colonized a large part of the middle and lower stretches of Navarre's rivers". To try to stop their expansion, the experts consider it essential to promote citizen participation in public and private initiatives aimed at the protection, conservation and recovery of these fish and their environment: "It is everyone's task to extend a more manager behavior regarding water -which is a scarce good-, and the care of our rivers, avoiding their pollution and favoring the sustainable exploitation of resources," concludes the researcher.