Photo: Bianca Killmann
Problems again due to Elodea in the Baldeneysee
In Baldeneysee in Essen, the largest of the six Ruhr reservoirs, it has been native for several years: the waterweed with the botanical name Elodea nuttallii. After three years of manageable growth, this summer the Baldeneysee This summer, the pond is literally overgrown and shimmers green instead of blue in large areas. A nuisance for all water sports enthusiasts who use the Baldeneysee for recreation and training and unfortunately also dangerous. Not only do water sports enthusiasts have to be careful not to get caught in the plant, they also have to avoid colliding with passenger ships.
Invasive species
The narrow-leaved waterweed is actually native to North America, but it has been spreading in Europe for years. Even in native waters such as the Baldeneysee. The popular lake in the Ruhr region is not only a popular destination for excursions, but is also used for sporting activities and competitions on the water. And this is exactly what is becoming a problem due to the proliferation of waterweed.
Fairway for passenger ships
Two mowing boats are supposed to keep the growth of this plant in check, but first the "Nimmersatt" was defective and in the meantime the GPS-controlled second mowing boat also broke down. When mowing, priority is apparently given to the passenger ships' navigation channel. Weiße Flotte Baldeney GmbH is a subsidiary of the city, which in turn also pays for the mowing costs. While in road traffic the "stronger" party is required to show consideration for the "weaker" party, it is apparently the other way round on the Baldeneysee apparently the other way around. This was the result of discussions with water sports enthusiasts. Using the mowed fairway of the passenger ships - a dangerous alternative.
Rapid growth
As the WDR reported, citing the regional association, efforts to curb the growth of Elodea nuttalli using other methods have had little success. Herbivorous fish, water harrows or removal with water pressure were tested as part of a research project. Although the waterweed indicates good water quality and should be seen as a good sign, its proliferation and rapid growth of up to 20 centimetres a day up to the water surface is also dangerous for water sports enthusiasts.
Danger from capsizing
Paddles, oars, sculls and propellers can become entangled and cause an accident. Once the athlete has capsized, the waterweed poses an immediate danger to life and limb if it wraps itself around the moving legs in the water. BaldeneyseeRuhr reported years ago about a young rower who had to be rescued by the DLRG after she capsized because the plants had wrapped themselves around her sculls. A television team from WDR recreated the situation with the student concerned and reported on it.
After three years of moderate growth, the waterweed is now back and stronger than ever.
