Dirk Schmeller, teacher-researcher attached to the National Polytechnic Institute of Toulouse, co-signed a study in April with his collaborator and companion Adeline Loyau, revealing the presence of 151 toxic molecules in eight altitude lakes in the Pyrenees.
Measuring devices, pipettes, landing net… The German scientist, specialized in functional ecology, and three members of his team carry out a battery of tests at an altitude of more than 1,600 m above Aulus-les-Bains , at the bottom of an Ariège valley.
If the glaciers, which will have disappeared in the Pyrenees by 2050, are the most telling witnesses of climate change, “the lakes are a source of life and are very sensitive, so they are a good indicator”, says Dirk Schmeller, 51 years old.
“These are the sentinels of global warming, he adds. I have been going to the mountains for a while, I see all the changes, and to validate these changes, I need to do scientific analyses”.
– The action of man –
In all, the researcher, based near Saint-Girons, in Ariège, since 2007, and his team go three times a year to each of the 28 Pyrenean lakes to take measurements.
The evolution of temperature, acidity, oxygen level is studied, but also that of the biodiversity present in these stretches of water of less than one hectare.
Using his specialization in zoology, Mr. Schmeller examines zooplankton, at the forefront of changes in the ecosystem, and performs surprising tests using swabs on tadpoles.
The aim is to detect diseases that are symptomatic of the degradation of water quality.
“The proportion of potentially toxic algae has also increased, this is an effect of global changes induced by human action, the introduction of fish, rising temperatures, pollution”, lists Dirk Schmeller, whose Pyrenean works began in 2007.
Among these major problems, the massive presence of two toxic molecules, diazinon and permethrin, used in particular as repellents against insects, and brought to altitude by herds in the mountain pastures or by hikers.
To carry out his analyses, the scientist integrates specialists from several disciplines into his teams: chemistry, microbiology, zoology, but also the study of water quality, as is the case for Pauline Benzi, doctoral student associated with the experience, which she considers “consistent” with the need to protect the environment.
– Alert launcher –
While contemplating the clear water of the Alate pond, perched at an altitude of 1,868 m and overlooked by the rounded Ariège peaks, Dirk Schmeller also deplores the presence of DDT, an insecticide banned since the 1970s, carried by the rains .
“We even find some at the North and South Poles, of course we find some here”, asserts this scientist with graying hair, who specifies that sunscreen, conveyed by tourists, is another polluting factor.
Dirk Schmeller and Adeline Loyau were delighted with the positive media coverage of their study. According to them, “environmental, animal and human health are linked. If we destroy mountain lakes, we take more risks of being sick!”
The researcher also tries to warn about this danger, by sharing behind the scenes of his research and popularizing it on a YouTube channel.
“Faced with climate change, the loss of biodiversity, everyone must be ready to change their way of life, our way of consuming, our comfort, our luxury”, he believes.
“It is important for us to raise awareness among all audiences because we cannot continue as we are doing,” he adds.