Pyrenees. Polluted mountain lakes: the edifying observation of researchers in Toulouse
By Hugues-Olivier Dumez
Published on
The results of the study are chilling. The crystal clear water of high mountain lakes is not as pure as it seems. Researchers from Toulouse have been detected more than 140 chemical molecules, some of which are toxicin several lakes Pyrenees. Analyzes were carried out in particular in the Massif du neouvielle (Hautes-Pyrénées), known for its rich flora and fauna. But also in Ariege and in the Bearn. The study was made public in early April 2022.
Insecticides, herbicides, fungicides,…
Contacted by News Occitania, Dirk Schmellerteacher atNational School of Agronomics of Toulouse, evoke the presence of insecticides, herbicides, fungicides, etc. We already knew that the oceans and rivers were polluted by human activity, but high mountain lakes? ” The DDT, a pesticide now banned, was found in Antarctica,” recalls the scientist. “Chemicals can be transported through the atmosphere to very remote places.”
The phenomenon is well known. “The novelty in this study is not only the great diversity of the molecules found, it is above all the favorable that they represent for the ecosystem commented Dirk Schmeller.
A source of concern for the environment
The results are indeed a source of concern for the environment. The Toulouse researchers have nominated themselves to the zooplankton, an animal plankton that feeds on living matter. “It’s a biological barrier that protects amphibians,” he explains, citing, for example, pathogenic fungi with phosphorus. And to add:
Because of this adequate, we note a reduction, even the local extinction, of the micro-crustaceans capable of ingesting significant quantities of phosphorus. Or they act as filters in the water. Consequently, the ecosystem is weakened by this pollution. The disappearance of crustaceans leads to an imbalance in the ecosystem with in particular the profusion of algae.
An impact on water quality
It also mentions an impact on water quality. This increase in pathogens could lead to a risk for humans. “Some molecules are known to be carcinogenic,” he warns. These mountain waters meet good in our faucet!
In general, Dirk Schmeller said he had observed changes over the past fifteen years. Algae growth, cloudy water,… “The cyanobacteria multiply,” he explains. “Our winters are no longer cold enough, the water in mountain lakes is no longer as pure as it once was”.
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