Michel Roggo's Image

Michel was diving near the water’s surface when he spotted a huge pike disappearing into the mass of aquatic plants below, called watermilfoil. He followed for a closer look and noticed that some supported thick clusters of zebra mussels. Glancing up he found himself immersed in an ‘underwater jungle with an endless view’.

Watermilfoils and zebra mussels are both prolific breeders easily spread by human activity. They have colonised fresh water far beyond their place of origin, causing harmful changes in the areas they are introduced into. Zebra mussels’ filter feeding increases water clarity, significantly reducing plankton densities and disrupting ecosystems.