Luxembourg's Ministry of Health has announced that cyanobacteria, also called "blue algae", have been discovered in various places along the Moselle river, particularly in slow-moving areas.

These bacteria are normally present in these waters, but under certain conditions they develop excessively and form coloured carpets (greenish-blue coloration or "mashed pea" colour).

Under these conditions, these bacteria can produce toxins that can cause health problems for humans and animals. These problems depend on the amount of toxins absorbed: skin

irritations, headaches, nausea, gastroenteritis, cramps, paralysis, liver damage...

The exact cause of this excessive bacterial proliferation is not known, but often results from inappropriate nutrient intake for these bacteria in the presence of a high water temperature.

It is therefore recommended for both people and animals to avoid contact with water where these coloured carpets are (swimming, water sports) and avoid swallowing this water.