Battle plan to repel nature's invaders

David Adam, The Guardian 29 May 08;

Foreign invaders with their sights on Britain's native plants and animals will be countered by a special rapid response unit, under plans announced by the government yesterday.

The Department for Environment, Food and Rural Affairs (Defra) said non-native species such as floating pennywort and American mink damage Britain's wildlife and cost the economy some £2bn a year. Under the plan, Defra says efforts to spot such invaders will be better coordinated and action to repel them taken earlier.

The plans for England, Scotland and Wales include educating people on the dangers of such species and a web-based directory showing which invasive plants and animals are found in specific areas and how they spread.

According to a study in 2005, there are more than 3,000 non-native species now wild in Britain, with some 2,721 in England alone - of which two thirds are plants. Climate change is expected to bring more foreign species, as rising temperatures encourage them to establish themselves in new areas.

Jeff Rooker, minister for sustainable food and farming and animal health, said: "The introduction of species over thousands of years has shaped British wildlife and the countryside that we love. But non-native species that are invasive can have a serious impact on native wildlife and are estimated to cost the British economy at least £2bn a year. "

Some of Britain's best loved wildlife, including bluebells, red squirrels and water voles, are threatened by invasive species. Water voles have declined by 90% since 1990 because of habitat loss and the spread of American mink which prey on them. British bluebells are threatened because they hybridise with Spanish bluebells. The red squirrel has suffered since the introduction in the 19th century of the stronger, more adaptable, grey squirrel.

Some invaders pose a risk to human health. The oak processionary moth has hairs that cause irritation, while giant hogweed sap causes blistering. Invasive non-native species can also affect agriculture, forestry and fisheries, Defra said.

The strategy also aims to co-ordinate existing programmes to tackle invasive species which have established themselves, Defra said. It is being launched as ministers and officials from around the world meet for the Convention on Biological Diversity in Bonn, Germany, to discuss attempts to halt the loss of biodiversity by 2010. Invasive species are considered to be one of the greatest threats - along with habitat loss - to wildlife worldwide.

A report this month from environment group WWF and the Zoological Society of London said that more than one in four of all individual animals, birds and fish on the planet have disappeared in just over 30 years.

Experts have put the cost of removing the invasive Japanese knotweed from Britain at £1.6bn. The plant has no natural enemies here and causes problems through rapid invasion of habitats, exclusion of other plants, and damage to property.
The invaders

Azolla fern
A fast growing floating aquatic plant, capable of spreading completely over lake surfaces in a matter of months.

Marsh frog
The amphibian giant that can grow to 17cm long has hopped across the channel.

Red-eared terrapin
Originally from the US, these foot-long former pets can terrorise ducklings.

American mink
Farmed until the 1980s, hungry escaped minks are blamed for the collapse in water vole numbers.

Japanese knotweed
Known in Japanese as Itadori, which means simply "strong plant". Gardeners across the country will agree.

Defra launches invasive species strategy
Caroline Gammell, The Telegraph 28 May 08;

Rising global temperatures are fuelling the growth of invasive foreign plants and animals in Britain and putting hundreds of native species at risk, the Government has warned.

The spread of these non indigenous species is considered the second biggest threat to British wildlife - after habitat loss - and costs the economy between £2 and £6 billion a year.

Iconic native plants and animals, such as bluebells, red squirrels and water voles, are all under threat.

The problem is expected to get worse as warmer temperatures encourage the migration of these hostile species, which include floating pennywort, American mink and Chinese mitten crab.

Agriculture, forestry and fisheries are all affected by the spread of such plants and animals, the Government said.

The Department for Environment, Food and Rural Affairs today launched its strategy to combat the problem, raising awareness of the offending plants and animals and plans to develop a "rapid response" to control the invasive species.

The scheme, which will affect England, Scotland and Wales, includes an online directory of where the foreign plants and animals can be found and how they spread.

Environment Minister Jeff Rooker said: "Non-native species that are invasive can have a serious impact on native wildlife and are estimated to cost the British economy at least £2 billion a year.

"And with climate change the threat becomes greater. For the first time we now have a co-ordinated plan to tackle this."

There are more than 3,000 foreign species flourishing in the wild in Britain and 66 per cent are plants. Although not all are invasive, those that are tend to colonise and dominate an area.

Hottentot Fig, originally from South Africa, grows up to a metre a year and one plant can spread to a 50 metre area if not controlled.

It chokes other native plants and threatens coastal habitats and is considered a particular problem on the Lizard Peninsula in Cornwall.

Japanese knotweed grows rapidly, dominating other plants and also causes damage to properties, growing through tarmac and floors.

The cost of removing the weed from Britain has been estimated by the plant charity Plantlife to be £1.56 billion so far.

Indigenous water voles have declined by 90 per cent since 1990 because of a combination of habitat loss and the spread of American mink which preys on them, while British bluebells are under threat because they cross-breed with Spanish bluebells.

The introduction of the grey squirrel in the 19th century is one of the best known examples of invasion by a foreign species, its ability to carry the squirrelpox virus which is lethal to red squirrels.

The native squirrel is now restricted to Scotland, Cumbria, Northumbria, the Isle of Wight and the islands of Poole Harbour.

White-clawed crayfish have suffered since the North American signal crayfish was introduced for commercial farming in the 1970s.

The foreign species carries crayfish plague which is deadly for the indigenous species and competes for habitat and food. White-clawed crayfish are now listed as globally threatened by the International Union for Conservation of Nature.

Dr Debbie Pain, director of conservation at the Wildfowl and Wetlands Trust where the Defra scheme was launched, said her organisation had struggled to control the American Azolla fern.

"Sadly we face a constant battle as species encroach from neighbouring waterways. Much of the problem is the lack of awareness of the damage some species can do."

Eladio Fernandez-Galiano, head of the Biological Diversity Unit at the Council of Europe added: "Invasive alien species is one of the rising threats for biological diversity.

"In these times of climate change, more and more species will arrive and spread in our native ecosystems changing their character and singularity."