Lower Saxony bans swimming in Lake Steinhude over blue-green algae

A high concentration of blue-green algae has prompted the Hanover region to close Lake Steinhude to swimmers. The ban also covers the Großer Ricklinger Teich, the Ricklinger Bad and the Ricklinger Siebenmeterteich.

Health department measurements showed a sharp increase in cyanobacteria, the region said. The swimming ban at the Ricklinger Dreiecksteich remains in force as well. Signs at the lakes identify the restrictions, which will apply until further notice.

Strong algae growth can make water look bluish-green and cloudy, with visibility below one metre and streaks on the surface. Wind direction largely determines where the algae gather along the shore.

Germany’s official bathing season runs from May 15 to September 15. Health department staff will continue to check water quality regularly through mid-September to limit possible risks. Cyanobacteria can multiply in warm weather and favorable environmental conditions.

Contact with contaminated water can cause skin or mucous membrane irritation, allergic reactions, nausea, vomiting and diarrhea. The algae can be especially dangerous for dogs, which may die after drinking affected water or chewing sticks contaminated with it.