THE impact of invasive non-native species to Gloucestershire’s native plants and animals is becoming a threat, according to a report published by Gloucestershire Wildlife Trust.
Plants and animals not native to this country but which have become established here are a major threat to the native wildlife.
The report highlights three species, Himalayan balsam, muntjac deer and American signal crayfish, which are out of control in Gloucestershire and altering long established habitats, pushing some native species to the verge of extinction.
Invasive non-native species are the second most significant threat to wildlife after habitat loss and the evidence can be found here on our doorstep.
Dr Colin Studholme the trust’s director of conservation said: “Movement of plants and animals around the world is having a devastating impact on native wildlife, whether the introductions were deliberate, such as exotic garden plants brought to the UK by the Victorians, or unintentional like zebra mussels which have found their way here in the bilge tanks of ocean going ships”.
It is estimated that ten new species become established in Europe every year and 25 per cent of these can be expected to have a negative impact. The cost to the UK economy from invasive species has been estimated to be a staggering £1.7 billion pounds annually. This includes the cost of controlling non-native species as well as the cost to agriculture, forestry, the water industry and damage to buildings.
Dr Studholme added: “At this time of year most of our river banks are pink with the flowers of Himalayan balsam, a vigorous invasive plant brought in as a Victorian garden plant but which is now rampant in the wild. It out competes native species and can cause bank erosion leading to increased flood risk.”
The report also highlights the impact of the American signal crayfish originally farmed in the UK for food but now on the loose in the wild.
The trust is calling on residents in Gloucestershire to be vigilant and take care to avoid unwittingly spreading these and other undesirable plants and animals.
Crayfish plague can be transferred on contaminated wellies, fishing equipment and boats, while even the tiniest fragment of some non-native aquatic plants - such as New Zealand pygmy weed, can expand to problem proportions if moved from garden ponds into the wild.
The trust also has regular work days to tackle some of these species - notably Himalayan balsam - in areas where they are a threat to special habitats.