The nine invasive species on the EU hit list in Ireland
NINE OF THE 37 species on the EU hit list of invasive aliens occur in Ireland and comprise the following four species of plants and five species of animals.
American Skunk-cabbage, a large ornamental arum with a foul-smelling, skunky odour when it blooms, is a garden escape. It is found scattered around the country and is locally common in boggy and swampy ground by waterways.
Curly Waterweed is native to southern Africa. It grows very quickly, is widespread and is spreading. For the past ten years it has posed a major problem in Lough Corrib, Ireland’s second largest lake, where it has formed dense stands to the exclusion of the local and native waterweeds.
Floating Pennywort is an American alien that is naturalised in rivers, canals and ponds. At present it appears to be confined to Northern Ireland but it is reported to be spreading rapidly. Its floating leaves are either round or kidney-shaped.
Parrot’s-feather comes from the Amazon River. It is an attractive underwater plant used in both indoor aquaria and outdoor garden ponds. Throw-outs and escapes from cultivation grow very quickly forming dense mats that can completely clog slow-moving waterways.
Chinese Mitten Crabs get their name from their hairy claws that give the impression that these natives of China are wearing mittens. They were first discovered in Waterford Harbour in 2005 and are migrating upstream into the lower reaches of the River Suir. It is believed that they probably arrived in Ireland via ship ballast water.
Red-eared Sliders are North American terrapins that used to be sold in pet shops until their sale was banned in 1998. They are mainly naturalised in the Dublin area, especially in park ponds, when unwanted pets were released into waterways by owners.
The Ruddy Duck is another North American alien than has escaped from wildfowl collections. The male has a bright chestnut-red body, black head, white cheeks and a large bright blue bill. It is widespread in Ireland.
The Grey Squirrel is abundant throughout all of the eastern half of the island of Ireland. This North American alien was introduced from England to Co Longford in 1911 and since then it has spread almost nationwide.
And finally, Muntjac are very small deer that are native to south-east China and Taiwan. They are escapes from estate collections and are found mainly in Northern Ireland. Otherwise they are thinly scattered with a larger concentration in Co Wicklow. They are reported to do serious damage to forestry plantations.