I first set foot in the Pyrenees in 2006. Two years later, I began a large-scale survey of mountain lakes and amphibian populations: from east to west, I covered more than 100 mountain lakes located in the eastern Pyrenees to the Béarn region (Pyrénées-Atlantiques).
For our various projects, we came back to sample the same lakes at least once a year. Over time, we noticed changes, in particular the increased growth of algae cyanobacteria and sometimes dinoflagellates, the blue-green algae that turn many lakes green. Back in 2012, we informed the Pyrenees National Park (PNP) about our observations.
