Invasive species have cost UK economy more than £5bn over past 50 years

The grey squirrel, European rabbit and Japanese knotweed are among the newcomers placing a financial strain on the economy. And they warn that the cost ‑ one of the highest in Europe ‑ will only get worse as more foreign species head for our shores.

Scientists from Queen’s University Belfast say the European rabbit destroys farmland. Aggressive Japanese knotweed damages buildings and can seriously hit their value.

Dr Ross Cuthbert, from the university’s School of Biological Sciences, said: “We have found the majority of costs were caused by direct damages, whereas very little was spent on the actual management of invasive species, and especially prevention of future invasions.

“Worryingly, we also found that invasion costs are increasing rapidly over time and are likely to continue rising as more arrive in the UK. These costs are also severely underestimated.”

Invasive species are plants or animals that have been introduced to an area by humans, creating ecological or economic havoc.

The UK has an estimated 3,000-plus non-native variants.

The researchers hope their work, in the NeoBiota journal, will raise awareness of “the huge economic burden invasive species have on the UK economy” and prompt better investment in biosecurity.