Wherever you go in the UK you will find invasive species. On the UEA campus, as well as the grey squirrels and rabbits, the 2009-2011 Biodiversity audit found many of these species.
Many cause several problems, like outcompeting the native species. However, never before has an invasive species caused enough problems for the sale of it to be banned in UK. From April 2014, any retailer who sells water fern, parrot feather, floating pennywort, Australian swamp stonecrop or water primrose may face a £5,000 fine or up to six months in prison.
These plants are often inadvertently introduced when they are bought as ornamental plants for the garden and then allowed to spread into the wild. One of the plants, floating pennywort (Hydrocotyle ranunculoides) was introduced to Britain from North America in the 1980s. It can grow up to 20 cm a day and therefore has potential to block rivers and waterways. In 2009 the Enviromental Agency started a campaign to clear it from the Trent and Tame rivers in Tamworth.
Environment Minister Richard Benyon announced the ban on 29 January, stating that it would save Britain millions of pounds worth of damage as well as allow fishers and anglers better access to rivers and lakes.