Non-native Invasive Species 

These are plants and animals from other countries that have been introduced and have become established outside of their normal habitat or native country.

Some non-natives are completely harmless however others, known as invasive or alien species, have the ability to cause damage to the environment, the economy, our health and the way we live. Non-natives can be transported to Great Britain in a number of ways including via recreational boating activity by hitching a ride on boat hulls, propellers or in ballast and bilge water. The spread of invasive species is becoming a major issue in both marine and inland waters around the world because they compete with native plants and wildlife and can cause major changes to waterways.

Fast-growing species like Zebra mussels are already causing problems in many areas, blocking engine cooling water intakes resulting in engines over-heating. Didemnum vexillum, known as the Carpet Sea Squirt, has a smothering effect; covering aquatic habitats in thick sheet-like growths and interfering with fishery and aquaculture operations.  Once established, non-native species become extremely difficult and expensive to eradicate.

As recreational boaters, there are a number of actions that we can take to minimise the risk of introducing or spreading non-native species around Great Britain. The presence of the ‘killer shrimp’ at Grafham Water highlights the potential issues that non-native species can cause for recreational boaters. It has also demonstrated how successful management techniques and good working relationships can help ensure that recreational boating activity can continue whilst limiting the further spread of a particular alien invader.

The RYA has been working closely with the GB Non Native Species Secretariat, the Environment Agency, Natural England, the Countryside Council for Wales, Marine Scotland and Invasive Species Ireland to develop guidance for recreational boaters on minimising the spread of non-native species. This guidance provides clear advice on simple steps that we can all take to limit the spread of these species by recreational boaters. It also contains advice on what to do if you find that a non-native invasive species has appeared in your local water.

For more information on how non-native species can affect biodiversity, human health and the economy, read this informative article by the European Environment Agency.

Further information on non-native invasive species can be found on the GB Non Native Species Secretariat website. Advice on boating best practice can be found on The Green Blue website.