Invasive non-native plant and animal species are the second greatest threat to biodiversity worldwide after habitat destruction. Ireland is no exception, and many species that have newly arrived to Ireland has disrupted local ecosystems and threaten our native biodiversity. New regulations have been introduced in the European Union and transposed into Irish law, to mitigate the threat posed by invasive alien species.  There are many contenders for Ireland’s most unwanted species, but  here we have profiled 10 species which we feel are particularly unwelcome.

Coypu

Coypu
The Coypu (Myocastor coypus) is a large, herbivorous, semi-aquatic rodent native to South America. It can weigh 5-9kg and is about 1m in length from head to tail. It has dark fur and a white muzzle, a long cylindrical tail and small ears. It also has distinctive bright orange-yellow incisor (front) teeth, and webbed hind feet. Coypu were introduced into other European countries for fur farming in the 19th Century, but they are very recent arrivals to Ireland, having been recorded in the wild only since 2010.  Where coypu have become established in Europe they can quickly build up large populations, impacting significantly on riverside vegetation and undermining riverbanks and flood defenses through burrowing (Photograph: Shutterstock).