Blue-green algae prompt caution at Lake Constance

Localized blue-green algae accumulations have appeared along Lake Constance, prompting Vorarlberg’s Environmental Institute to advise caution, ORF reported. The affected spots are the Wocherhafen harbor and Seecamping in Bregenz, as well as Kaiserstrand and the harbor in Lochau.

Bathing visitors and young children should avoid these areas, said Gerhard Hutter, head of water quality at the institute. Dog owners should be especially careful because cyanobacteria can be dangerous if swallowed with the water. Possible symptoms of poisoning include vomiting, diarrhoea and nausea.

Blue-green algae can produce toxins, but not all do. Scientists have not fully established why some cyanobacteria produce toxic substances and others do not, Hutter said.

The accumulations are not unusual and can occur in Lake Constance depending on the weather, temperatures and currents. They often appear in summer but can also occur in autumn. Rain, such as that in recent days, can make them disappear relatively quickly.