Protect our waterways from invasive species


The RYA and its joint environment campaign with British Marine, The Green Blue, are supporting Invasive Species Week (13-17 May), giving clubs a chance to get involved and protect the UK’s waters from non-native species.

Around 2,000 non-native plants and animals from all over the world have been introduced to the UK by people. Water users may unknowingly be spreading them from one water body to another as animals, eggs, larvae and tiny plant fragments can easily be carried on equipment, shoes and clothing. Some can survive out of water in damp conditions for more than two weeks.

Invasive non-native species can block up waterways, make navigation difficult and cause irreparable damage to the environment. Once in a waterway they can disperse rapidly, adversely affecting recreational facilities, reducing fish populations and restricting navigation.

Everyone can help to prevent their spread by following the Check Clean Dry routine and by putting up a sign to remind fellow boaters to do the same. Sharing a photo of biosecurity in action on social media under #InvasivesWeek will also help to promote your club.

Since the launch of the Check, Clean, Dry campaign in 2011, The Green Blue has provided a wealth of information and guidance to inland and coastal clubs about the steps they can take to minimise the spread of non-native species.

How can I get involved?

  • Put up a Check, Clean Dry sign to nudge fellow boaters into action.
  • Share a photo on social media under #InvasivesWeek to promote your club’s activities.
  • Remind your club members that they may be unknowingly helping to spread invasive species from one water body to another.
  • Access the free online training to learn more about non-native species, how to identify them and how you can prevent them from spreading.
  • Become a Check, Clean, Dry champion and contact The Green Blue for free materials you can share with other members of your club to raise awareness.

Some of the species threatening our environment


Carpet sea squirt - Fact Sheet   

  • While each individual organism is tiny (1mm long), carpet sea squirt grows in colonies which can cover several square kilometres and any other species in its way.

American lobster - Fact Sheet  

  • Much larger and more aggressive than the European species, American lobster could threaten native lobsters and other economically important species, such as brown crabs, through competition and disease.

Slipper limpet - Fact Sheet 

  • These form chains and stacks which can contain up to 15 individuals.
  • They can starve and smother native shellfish and be a serious pest to oyster and mussel beds.

Freshwater and riparian

Floating pennywort - Fact Sheet

  • Originally introduced as an ornamental pond plant, floating pennywort can be spread if unwanted plants are not properly disposed of, or by recreational water users on boats, clothing and equipment.
  • The plant rapidly forms dense mats which affect oxygen levels in the water, crowd out and kill off native wildlife, and damage habitat.

Killer shrimp - Fact Sheet

  • This is established in a small number of waterbodies in England and Wales.
  • The killer shrimp can be spread by recreational water users on boats, clothing and equipment.
  • It is a voracious predator regarded as one of the most damaging invasive species in Europe.
  • In addition to harming native species, it can reduce the quality of fisheries and impact on recreational water use.

For more information, visit Follow the campaign on Twitter @CheckCleanDry and @TheGreenBlue #InvasivesWeek