THE DREISSENA POLYMORPHA IN SPAIN
Since the first signs of the presence of the zebra mussel in August 2001 were detected in the lower Ebro, the expansion has been constant and today, fifteen years later, we can say that most of the basins, except Duero and Sil, are Are affected to a greater or lesser extent.
We consider that in a period of 5 years D.p. It will have conquered the entire hydrological system of the country. If we add to this species other invading bivalves (fluminea-Asian curvilinear clams), which have already been introduced into the main rivers, the situation becomes complex and difficult to solve.
Damage produced, both environmental and economic, is difficult to assess, as there is no accurate data. The European Commission has estimated losses of all species considered exotic and invasive by some 12,000 million euros. If we consider that dreissena polymorpha is one of the most aggressive and with the greatest capacity for expansion, we can give an idea of the scope of the problem.
Main sectors affected
We must establish two differentiated parameters, although closely linked in their origin: ecological and economic damages.
In the first, we can ensure that many native species have disappeared or are about to disappear. These represent a serious imbalance for biotic factors.
On the economic side, we highlight the impact on industries that use water as an essential element for their normal operation (hydroelectric, nuclear power plants, etc.). Irrigation systems are another of the sectors most affected. Although not mentioned, drinking water networks are another important threatened districts
The distribution on the map has been prepared by the Ecowater Technologie team, based on their own research and with the collaboration of public and private organizations. The map is updated every three months. The last one was made in November 2016. We are also developing the risk maps that we will be presenting shortly.
SYSTEMS AFFECTED OR WITH HIGH RISK OF INVASION