DAMAGING invasive species have been highlighted in a report published by Gloucestershire Wildlife Trust.
The report highlights three species which are particularly out of control in Gloucestershire - Himalayan balsam; muntjac deer and American signal crayfish.
Non-native species are the second most significant threat to wildlife after habitat loss and some are pushing native species to the verge of extinction.
On top of this the cost to the UK economy from invasive species has been estimated to be a staggering £1.7 billion pounds annually.
The Wildlife Trust is calling on residents of Gloucestershire to be vigilant and take care to avoid unwittingly spreading these and other undesirable plants and animals.
Crayfish plague, carried by American signal crayfish, can be transferred on contaminated wellies, fishing equipment and boats.
Dr Colin Studholme the Trust's Director of Conservation explained: "The future for our native white-clawed crayfish looks bleak.
“We can expect it to be extinct in the wild in a decade apart from at a few remote sites which have been specially selected and to which remnant populations are being moved out of harm's way".
Dr Studholme added: "We are also very concerned about the rapid spread of muntjac deer which are present in most of Gloucestershire's ancient woodlands and have a taste for bluebell bulbs"
"They also have a habit of browsing young tree and shrub shoots which prevents regeneration, changes the long term structure of the woodland and impacts on a whole range of other species.
The Trust also stressed that even the tiniest fragment of some non-native aquatic plants can expand to problem proportions if moved from garden ponds into the wild.
The Trust has regular work days to tackle some of these species - notably Himalayan balsam - in areas where they are a threat to special habitats.
It is estimated that ten new species become established in Europe every year and 25% of these can be expected to have a negative impact.
More information can be found at http://www.gloucestershirewildlifetrust.co.uk/