Topmouth Gudgeon: The Empire Strikes Back

Strategic management of invasive freshwater fish on a national scale:

The GB Invasive Species Framework Strategy requires Government Agencies to take rapid action to contain, control and eradicate high risk invasive species. Topmouth gudgeon is one of the most damaging non-native fish species to invade Western Europe. Should topmouth gudgeon become established in UK waters, the impacts on our native species and the fisheries they support would be significant. Colonised sites including isolated ponds, lake complexes, fish farms, wetlands and stream systems presented significant challenges to conservation managers, who had no effective means to respond to this threat. The Environment Agency developed a specialist team to deliver a piscicide based eradication programme. Implemented in 2011, the 5 year programme aims to achieve total removal of the species from England by 2017. This approach proved to be highly effective; of the 21 confirmed sites, 18 have been eradicated. With only 3 confirmed sites remaining, the eradication programme is on schedule for completion by 2017. The techniques and expertise developed through this programme provide us with the capability to manage invasive fish species, but also the potential to respond to new threats from other invasive aquatic species including crustaceans, amphibians and invertebrates.