Our work River work Tackling Invasive Species Invasive species are a serious problem to our native flora and fauna. Some can also be a threat to people and property. The Foundation's habitat teams tackle invasive animal and plant species on an almost daily basis. Our Giant hogweed programme has almost eliminated this poisonous plant on the Wye and good headway is being made on the Usk. Japanese knotweed is a problem plant too. It has the ability to grow through concrete, so is a threat to people's homes. More details on our Giving Up The Weed project. Of the fauna, the American signal crayfish is perhaps top of the list of concerns for us. It significantly reduces biodiversity in rivers and can carry a disease that kills our native, endangered Whiteclaw crayfish. We also have to deal with other invasive fauna such as mink. By far the most effective way of minimising the damaging effects of invasive species is to prevent them entering our rivers in the first place. The Foundation raises awareness amongst those that use the rivers for recreations (anglers and canoeists) to the threat that alien species pose and how to prevent their spread. We are very grateful to Esmee Fairbairn Foundation, Natural England, Environment Agency, Natural Resources Wales, Brecon Beacons Trust and Keep Wales Tidy for their help in this area of our work.