© Jeannot Ries / RTL Télé Lëtzebuerg
The recent warmer temperatures have introduced a new phenomenon during the summer over the past few years. Every year around this time, blue algae become an irritant for those hoping to swim in Luxembourg's lakes and rivers.
The phenomenon is not limited to Luxembourg, but the Grand Duchy experiences cyanobacteria every year. This year, the first incident was discovered in the Moselle river in the middle of August. This past week, the news came that blue algae were found in the upper part of the Upper-Sûre lake.
Guess who's back: Blue algae: swimming prohibited at "Romwiss" at Upper-Sûre lake
Officially, there are only three body of waters approved for swimming in Luxembourg: the Upper-Sûre lake, the Weiswampach lake, and the "Baggerweieren" ponds in Remerschen. All three of these lakes were rated as having an excellent water quality, as per EU norms, for the season from 1 May to 30 September.
But blue algae are steadily becoming a local phenomenon and a headache. Blue algae blooms release toxins that can cause skin rashes, nausea, vomiting, stomach pains, and fever. In severe cases, blue algae can lead to liver and brain damage. Consequently, where a body of water is found to produce blue algae, both humans and pets such as dogs should avoid any contact with the water.
Last year, blue algae saw the Upper-Sûre lake completely closed to swimming activities, but this year, only the area by 'Romwiss' is affected. This does not necessarily mean that the other parts of the lake and other lakes in Luxembourg haven't got blue algae blooms. The toxin concentrations are simply low enough not to constitute a risk to swimmers.
But how exactly does cyanobacteria produce itself? Experts say these blue algae flourish in hot weather and dry conditions.
The Echternach lake is considered a special situation. The lake is not considered as officially-approved bathing water, but remains popular among those doing watersports.
However, given its lack of classification, the lake is not subject to intense supervision for blue algae. If a specific case of blue algae were to be found, the Sanitary Inspectorate would have to decide how to react.
