Overview
- Volunteer and club-led removal efforts intensified Tuesday at Schiersteiner Hafen with mowing boats, grapples and hand raking to free training lanes and moorings.
- The outbreak is driven by Elodea species — chiefly Elodea nuttallii and Elodea canadensis — with E. nuttallii listed by the EU as an invasive species and largely displacing the other locally.
- Warm temperatures, low water and nutrient-rich inflows let light reach the riverbed in sheltered arms, which fuels rapid, metre-long Elodea growth in harbour basins and side channels.
- Clubs report repeated multi-day operations cost thousands of euros, force event cancellations and leave volunteers at capacity because plants regrow fast from small fragments.
- Authorities say chemical controls are largely prohibited, no local predator exists, and the Waterways and Shipping Office warns drifting plants foul buoy chains and raise maintenance costs, so managers expect recurring clearances.