The Eden Rivers Trust report:
A variety of plants and animals are lurking outside of the Eden Valley ready to infiltrate and take over its waterways, but the Eden Rivers Trust is galvanising action to help prevent this from happening.
Invasive species threaten the native wildlife of our waterways and the cost of their management has been estimated at £1.7 billion in the UK annually.
Some of the invaders of real concern include:
• New Zealand pigmy weed – an aquatic and terrestrial plant that is already choking some of the large water bodies in the Lake District.
• Floating pennywort – an aquatic plant that grows up to 20cm a day and its management currently costs the UK £23.5 million a year. It is not yet known to occur in Cumbria but it has advanced as far north as Middlesbrough and Blackpool.
• Killer shrimp – a voracious invertebrate predator which preys on other invertebrates, fish eggs and small fish. Not in Cumbria yet, but there is a real risk of it hitchhiking on equipment like boats from places like the Norfolk Broads.
• Topmouth gudgeon – a prolific small fish which can cause a dramatic reduction in the number of native fish. It has already been eradicated from one Cumbrian tarn and there are no other known populations in Cumbria at the moment.
• Signal crayfish – discovered for the first time recently in a small tributary in the River Eden system. They can cause serious damage to the river banks with their burrowing and reduce the numbers of a range of other animals that live in the river. It is therefore critical that they do not spread.
• Crayfish plague – a fungal disease that some non-native crayfish can carry. It has already caused the disappearance of the native white-clawed crayfish from many UK rivers. It is possible that the Cumbrian signal crayfish population carries it and certainly populations elsewhere are infected.
• Gyrodactylus salaris – is a fish parasite which has caused the extinction of Atlantic salmon in some Norwegian rivers. If introduced into the UK it could result in enormous environmental and economic damage.
These invaders can be brought into the area by anything used in rivers and lakes, including any equipment used for recreation or work involving waterways.
The Trust is campaigning to encourage anglers in particular to ensure that their equipment is free of any invasive plants, animals or diseases. The campaign highlights that the addition of any plant animal or disease into the River Eden or any of the lakes, streams and becks that feed it, could cause as much damage as pouring a toxic chemical into the river.
There are posters and leaflets, inspired by similar work in America, to support the campaign, giving advice on some simple steps that can be taken to minimise the risk of carrying any hitchhikers between water bodies. The Trust is already working with local angling associations to ensure that the risk of introduction and spread are minimised.
During the summer there will be cleaning stations at several organised angling events to ensure that they are biosecure. The Trust will also be leading work parties over the summer to manage some of the invasive non native plants that currently occupy the river banks and volunteers are always welcome.
Paul Greaves, Invasives Species Officer with Eden Rivers Trust said:
“It is really important that people think about this when moving from one water body to another, otherwise the wildlife and landscape of our rivers could be damaged forever.”
Invasive non native species can have many serious effects on our rivers impacting not only on the plants and animals, but also on people that live next to or enjoy the river. Their introduction can lead to the total loss of the native plants and animals either through competition or through disease. They also have the potential to increase the risk of erosion and flooding. Access and enjoyment of rivers and lakes can also be reduced as a result of their introduction.
Although this campaign targets anglers there is a need for everyone that uses rivers lakes and streams to make sure that their equipment is clean and dry before using it again.
For further information contact Paul Greaves on email invasives@edenrt.org or by telephone on 01768 866788. The campaign posters are attached to this news page as PDF files for download.
