Invasive fish under control

2002/11/08 Orobengoa, Olatz - Elhuyar Zientziaren Komunikazioa

• Abeltzaintza
• Biologia
• Arrantza
• Ingurumena

Normally, when the new species begins to damage the ecosystem, experts realize that they are facing a new epidemic. And many times it is too late to solve the problem. The control of the new species introduced in an ecosystem is very difficult and costly, so the previous knowledge of species susceptible to being invasive can be much more advantageous. A group of American scientists has developed a mathematical model to know species of potentially invasive fish.

We have taken into account the characteristics of 45 exotic species of fish that inhabit the Great Lakes and analyzed what the invader does. The species appear to have four common characteristics: they resist large margins of salinity and temperature, grow rapidly and have provoked invasions elsewhere.

According to the model made by the scientists, in the ballast of the ships five of the 66 species that can reach from the Black Sea and the Caspian Sea to the Great Lakes have a great probability of being invasive. One of the five species has already passed from the Caspian Sea to the Volga River and may soon also reach the Baltic Sea and the North Sea.

The model is only valid for Great Lakes, since the database of all its fish species is very complete. However, experts consider that it can be a good basis for developing a more general model, since if there is a general system that knows potentially invasive species, actions can be prepared to avoid their introduction and establish stricter controls.