Published Thursday, 30 May 2013
Floating pennywort, an invasive species in NI, grows 20cm a day. (© GBNNSS)
The figure was announced on Thursday as Environment Minister, Alex Attwood launched the first ever Invasive Alien Species Strategy for Northern Ireland.
Examples of invasive alien species include Japanese knotweed, floating pennywort and Zebra mussels.
An invasive alien species is a species that has been introduced to a country where it is not native that has since become a nuisance through rapid spread and increase in numbers, often to the detriment of native species and the economy.
A range of invasive species have historically been introduced into Northern Ireland intentionally before their harmful impacts were known whilst others have arrived as hitchhikers.
The problem is economical as well as environmental and the ecological effects are often irreversible and once established, they can be extremely difficult and costly to control and eradicate.
They are a risk to our unique flora and fauna, our economic interests such as forestry, fishing, and farming, our health, and our recreational interests.
In the past 20 years we have also seen an increase in the numbers of invasive aquatic plants and invasive marine species being detected in our environment.
Environment Minister Alex Attwood
"Increasing awareness of the threat of invasive species and the need to tackle them is key to achieving success," Minister Attwood said.
"In Northern Ireland we have been subject to the impacts of invasive species that have been introduced over hundreds of years.
"Our ancestors in Victorian times, for example, introduced several invasive plant species such as Japanese knotweed and Giant hogweed which are now widely established."
He said the key to solving the problem is government, community and environment groups working together, after pennywort has been eradicated from two sites in Northern Ireland through a series of partnership projects.
Other catchment control projects are ongoing in a number of sites across the region.
Floating pennywort, one of the most invasive aquatic plants, was first detected in Northern Ireland in 2002. It can grow at a rate of 20 centimetres a day enabling it to quickly take over a water body if it is not controlled.
Sites in Northern Ireland which have been invaded by floating pennywort, such as Glastry Clay Pits on the Ards Peninsula, have demonstrated the serious impact this plant can have on our freshwater environment if it is not tackled quickly and further introductions prevented.
Japanese knotweed, which can spread by tiny fragments, grows rapidly enabling it to out-compete our native plants. It has also been shown, in some cases, to cause damage to properties, growing through tarmac and floors and costs millions of pounds each year to control.
One of the most well known examples of an invasive species is the grey squirrel, which arrived from America in the 19th century and has endangered the life of the native red squirrel.
© UTV News