Exotic pets released into the wild are putting native animals at risk by spreading disease and competing for resources.

A new report has warned that a lack of information on the types of species traded in Ireland means that a proper risk assessment cannot be carried out. It also called for a national database of traded pets to be set up.

The National Biodiversity Data Centre said that invasive species cost the economy as much as €261m a year. Worryingly, one in four 'high risk' species have been recorded in the last decade.

Pets which grow very large, reproduce easily or require specialised care are the most likely to be introduced into the environment.

They can prey on native wildlife, compete with plants and animals for resources, and introduce and spread diseases.

Even pets not considered exotic, such as cats, rabbits, goldfish and other fish species, can have major negative impacts on native biodiversity.

The report - 'Ireland's invasive and non-native species - trends in introductions' - noted that with increased globalisation there was an increase in movement of non-native species across the world.

"Invasive non-native species are a threat to our biodiversity ecosystem functions and have a cost to our economy," it said.

"Of the 377 recorded non-native species in Ireland that were risk assessed, the majority (66pc) are at risk of low impact, 21pc ranked with a risk of medium impact and 13pc ranked as having a risk of high impact.

"The trend in introductions has increased dramatically since the beginning of the 20th Century and has accelerate further in the last decade. Most of the species are native to North America and Asia."

It added that the vast bulk of species were plants, and that most (67pc) were on land, followed by 21pc in freshwater environments and 12pc in marine.

The implications are "immense, insidious and usually irreversible", said the World Conservation Union, because of their impact on wildlife, economic activity and human health.

Among the species listed as high risk were the American mink, Asian clam, grey squirrel, harlequin ladybird, giant hogweed and feral ferret.

The report also found:

Some 377 species were assessed as being recorded up to 2012. Another 342 have not yet been recorded in Ireland, but were considered likely to arrive in the future;

127 species are assessed as being high or medium risk;

Of the 48 high-risk species, 12 were recorded in the last decade. Another three medium-risk species were also recorded since 2000;

The highest number of high-impact species are from Asia (29pc), followed by North America (20p), Europe and the UK (16pc), Eurasia (15pc) and Australia (8pc);

'Citizen science' is key to detection, with members of the public reporting many new species found in the last decade.

The report found that the "process of biological invasion" was changing constantly with new species arriving to our shores on a regular basis.

The initial response is crucial, including early detection and early warning systems.

While a rapid eradication programme is needed in many cases, prevention of the spread of some species including the Harlequin ladybird "may not be feasible once the species becomes established".

The report makes 10 recommendations, but said the "reality" for policy-makers was that "limited resources" were available to prevent and respond to threats.

It also warned about the need for a database of invasive species, including exotic pets.

"One significant recent development has been the increased reporting in the wild of traded pet species that have the potential to become invasive in Ireland.

"An openly accessible database of these traded species should be available to better assess the risk of future introductions to the wild."

Irish Independent