Buttermere is now the last pristine lake in North Cumbria

8th August 2023 - General Catchment

West Cumbria Rivers Trust and the National Trust ask water users to be vigilant of aliens 

West Cumbria Rivers Trust and the National Trust are asking locals and visitors to the Lake District to be vigilant about the problem of ‘aliens’. Not the little green men from outer space, but alien species non-native to Britain. They are appealing for all water users to help them by being aware of the issue and taking steps to help stop the spread.

Invasive non-native species (INNS) such as New Zealand Pigmyweed are incredibly adaptable and the smallest fragment can easily attach itself to a piece of clothing or equipment such as a boat, paddleboard, wetsuit, or angling equipment. In moving from one body of water to another, adventure seekers can accidentally introduce the aliens into waters previously unaffected, wreaking havoc on the water’s ecosystems. Once introduced, within a short period of time, the species can dominate the waterway forming dense mats, depleting oxygen for other plants, fish and invertebrates and restricting access for recreational water users. This non-native species is already present in Bassenthwaite Lake, Derwent Water and, to the dismay of local conservation bodies, it’s been recently found in Crummock Water – hitherto a pristine lake. Buttermere is now the only lake unaffected in the Derwent catchment, and the trusts need everyone’s help to ensure it stays that way.

West Cumbria Rivers Trust and the National Trust are working together to devise a plan of control for New Zealand Pigmyweed in Crummock Water and to raise better awareness of INNS in Cumbria. It is especially important that people using the waterbodies are aware of the issue and know how they can help to stop the spread. Every time you exit a waterbody, remember to follow these steps:

Check all clothing, footwear and equipment for plant fragments and living organisms before leaving a waterbody. Pay particular attention to any crevices!

Clean and wash all equipment on site, leaving all organisms and plant fragments behind. OR wash on a hard standing surface away from a draining system.

Dry all equipment and clothing thoroughly before heading to the next waterbody. Some species can survive for two weeks in damp conditions. 

Izzie Mullin, WCRT’s Invasive Species Project Officer, said:

“We want everyone in the Lake District to be able to enjoy our lakes, tarns and rivers, but we can only keep these fantastic natural resources accessible to people if they are in healthy conditions. We need the help of everyone who comes through our area to be aware of the issue and help us #SpreadTheWordNotTheWeed and prevent the introduction of new INNS.”

Joe Bagnall, the National Trust’s Riverlands Ranger said:

“The importance of a healthy and functional natural environment cannot be overstated for the benefit of all our well-being, therefore it is the National Trust’s goal to ensure that the fantastic lakes and rivers in our care are kept in healthy conditions allowing people to enjoy them forever.”

Those who live locally who want to do more to help protect our wonderful waters are encouraged to get in touch with West Cumbria Rivers Trust who are looking for biosecurity guardians to help keep an eye out for any new introductions to Derwent Water. Please contact Izzie Mullin at izzie@westcumbriariverstrust.org for more information.