What are Invasive species and how do they impact us?

Posted: 23 May 2024

Himalayan balsam

There are over 2,000 plants and animals in the UK that are damaging our natural ecosystems and pose a threat to our water bodies. These are known as invasive non-native species, also known as INNS.

Most are harmless but around 10-15% become INNS which spread and can have a harmful impact on the environment and the economy.

This week is Invasive Species Week, an opportunity to raise awareness of these plants and animals, their impacts, and the simple things that everyone can do to help prevent their spread.

Each year it costs the water industry £7.5 million to manage and control these species. For instance, the spread of zebra and quagga mussels, are a growing concern as they can damage and block pipework, putting a strain on our water resources.

Zebra muscles beside a South Staffs hat for scale What are we doing to tackle INNS? Over the past five years, we have surveyed over 90 of our sites for INNS so we can implement detailed habitat management plans that control and reduce the spread.

This includes Blithfield Reservoir, which provides up to 100 million litres of water each day to more than half a million houses and businesses in parts of the Black Country, East and South Staffordshire and South Derbyshire.

On site we have our Estates team who actively manage several invasive species including: Himalayan balsam, zebra mussels and American signal crayfish.

Jack Corcoran, a member of the team shared: “Our role at Blithfield involves monitoring the water flow at the reservoir regularly and sampling the water on a weekly basis. As well as this, we fulfil stewardships and grants for grassland and woodland habitats, maintain the fish farm and liaise with our stakeholders: Blithfield Anglers and Blithfield Sailing Club."

Jake Garrett, another member of the team, added: "The main invasive non-native species we have at Blithfield are rhododendron, Himalayan balsam, mink and grey squirrel. These are the ones that we have management plans in place for, or we manage through a grant or stewardship.”

Check, Clean, Dry INNS pose a risk to our enjoyment of nature, particularly our water bodies.

For this reason, we have biosecurity measures in place at our sites including the ‘Check, Clean, Dry’ protocol to help stop the spread of INNS. Invasive species are easily spread by damp equipment and clothing so for anyone visiting a water body for angling or sailing, we always encourage ‘Check, Clean, Dry’.

  • Check your equipment and clothing after leaving the water for mud and any aquatic plants or animals, removing anything you find and leaving it at the site.
  • Clean equipment and clothing as soon as possible and before leaving the site, using hot water if possible.
  • Dry everything off for as long as you can before using again as some invasive species can survive for over two weeks in damp conditions.

INNS at homeIt’s not only at our sites where invasive species can pose a threat. You could have invasive species at home.

Some of the plants in your garden or pond can become invasive non-native species if they spread beyond your garden border and these can cause harm to native wildlife.

Using the online ‘Be Plant Wise’ tool, you can choose the right plants for your garden that won’t harm native species and learn how to dispose of your garden waste responsibly.

To find out more about invasive non-native species, click here.