Considered one of the world’s most dangerous invasive alien species (IAS) for its economic impact and impact on ecosystems, the zebra mussel is already present in eight of Spain’s fifteen hydrographic borders, after adult specimens were found in Segura. basin.
Segura Hydrographic Confederation (CHS), view Talav reservoir (Albacete)He will be emptied up to a certain level (the zebra mussel lives at a depth of about 2-5 meters) to cause the existing specimens to dry out and thus prevent their spread.
According to the data of the Ministry of Ecological Transformation, the zebra mussel is also found on the borders of the Andalusian Mediterranean Basin, Guadalquivir; Guadalete and Barbat; from Tinto, Odiel and Piedras; Júcar, Ebro and Catalonia River Basin Region.
Miño-Sil, Galician Coast, Eastern Cantabria, Western Cantabria, Duero, Tagus, Guadiana, that is, the “silica” part of Spain was liberated.
According to Concha Durán, head of the Júcar Hydrographic Confederation Technical Service and expert on this invader, it makes sense for the zebra mussel to settle in “calcareous” Spainbecause it needs calcium carbonate to form its shell.
Zebra mussel in ‘top ten’ of the most dangerous ISS on the planet due to major socioeconomic and ecosystem impacts (does not pose a danger to human health) and her getting anywhere is always “bad news,” Durán complained.
The Segura boundary was one of the few borders still unaffected, possibly due to the control exercised over boats and species monitoring, according to Durán, who stressed the need to be “hard” when spotted.
“brutal” ecological impact
In addition to unloading, Stopping the use of the Talave reservoir (fishing and navigation) Durán says he’s conducting an extensive study to see how far the zebra mussel population has progressed.
“After years of experience, my advice is this: You must be very tough in the beginning, when something can be done. Only then can you learn to live with the problem,” he added.
This species is grouped into “very large” clumps that form balls that can block any water intake. Major damage to hydroelectric power plants, irrigation devices, municipal buildingsand such.
At an ecological level, its impact is “brutal” because when it lands on any solid surface, including other crustacean species whose survival is threatened.. Also having a “very strong” filter consumes a lot of phytoplankton and it can change an entire ecosystem.
According to Francisco Oliva, professor at the University of Murcia and coordinator of the Life Invasaqua project, if a population’s settlement is confirmed, what is expected is that it will disperse at a similar rate and with similar characteristics to that seen in nearby basins. , to fight against IAS.
he gave high reproductive capacity (one specimen may release more than a million larvae per year) and absence of certain predatorsIn a basin like Segura, socio-economic impact could be disastrous for agriculture.
Some confederations have already spent more than 30m euros on the direct management of the species and, A study at the Ebro Hydrographic Confederation estimates indirect losses at more than 1,600 million. explained why the zebra mussel.
Ban boating and fishing
Reservoir level reduction and extensive sampling to determine the true extent of the population, Temporary prohibition of activities that could lead to the spread of larvae into other reservoirs or water systems, such as boating or sport fishingOlive commented.
“It is very likely that this species will colonize the Segura basin via the Tajo-Segura transfer. Scientists and technicians have for years, filter stream “It constantly reaches the Talave reservoir from areas infected by zebra mussels in the Júcar river basin,” he complained.
“We found the first adult individual a few weeks ago. So far, only larvae with significant morphological damage (non-viable individuals) and very low concentrations have been detected,” said the head of the Segura Hydrographic Confederation’s Water Quality Service. , Sonia Hernandez.
“Fortunately, we caught it at a very early stage of colonization and only isolated individuals were seen.Explaining that for the water level to drop 6 or 7 meters, the reservoir will be partially emptied and the samples in the region will die from drought, Hernández said, “Then they will continue training.” comprehensive checks both in the affected reservoir and downstream.