Non-native species cost economy £1.7bn

Invasive non-native species such as grey squirrels and Japanese knotweed cost the British economy £1.7 billion every year, a new report suggested.

The researchers found that when such species take hold, crops, ecosystems and livelihoods can suffer.

The cost to the Scottish economy is £251 million a year and to the Welsh economy £133 million, according to the study, The Economic Cost of Invasive Non-Native Species to the British Economy.

Costs to the English economy are significantly higher at £1.3 billion because more invasive non-native species (inns) have become established there.

The rabbit is the most economically damaging species, followed by Japanese knotweed.

Other creatures in the top 20 include the rat, the house mouse and the mink, along with plants such as the rhododendron and giant hogweed.

The research was carried out by international scientific organisation CABI for the Scottish Government, Defra and the Welsh Assembly Government.

Ministers said the report showed early action was the best way to tackle invasive non-native species.

Richard Benyon, Defra Minister for the Natural Environment, said: "Invasive non-native species have a significant impact on the British economy and damage our own wildlife. The costs of controlling these species will rise unless society takes steps to prevent them taking hold and spreading.

"It becomes increasingly difficult and costly to control invasive non-native species as they become more established. Taking early action may seem expensive, but this report shows that it is the most effective approach, saving money in the long run and helping our native wildlife to thrive."

An inns has the ability to spread rapidly and become dominant in an area or ecosystem and all are species that have been released either deliberately or accidentally outside of their natural range.

The total cost of inns to the British agriculture and horticulture sector alone is around £1 billion a year.

The study investigated the impact of five species, the Asian long-horned beetle, carpet sea squirt, water primrose, grey squirrel and coypu, an aquatic rodent.

It found early action provided a significant economic benefit compared to the cost of management if the species were to become more widely established.

Roseanna Cunningham, Scottish Government Minister for Environment and Climate Change, said: "We all know about the serious threat to our native wildlife from invasive non-native species, and this report confirms the huge cost to businesses and individuals in Great Britain every year.

"A better understanding of the negative impacts of invasive non-native species can help us raise awareness to help prevent introductions in the first place and to better respond to problems."

Jane Davidson, Minister for Environment, Sustainability and Housing in the Welsh Assembly Government, said: "We in the Welsh Assembly Government are committed to protecting and enhancing our biodiversity and to understanding its relationship with, and impact on, our economy.

"This report will help us to prioritise and target where actions can have the most impact, and will assist us in prioritising our resources for action in the future."