How to avoid spreading invasive species

Updated:15 October 2010

Invasive non-native species are plants and animals from other countries that are introduced to Great Britain by people and have the ability to cause damage to the environment, the economy, our health and the way we live.
Invasive non-native species can be easily spread on equipment and in water, for example as small fragments of plants which can regenerate, as tiny (sometimes microscopic) larva and as eggs. It is important that this spread is controlled to minimise their impacts. Some of the ways in which they can be spread around the inland waters of Great Britain is via boat hulls or propellers, on dinghy trailers, or within bilge or engine cooling water systems.
The risk of spreading invasive species can be limited by following some simple rules:
* Inspect and clean your boat and kit before and after use. Be careful to check all kit, including ropes and chains. Be particularly vigilant when moving your boat from one water body to another.
* Do not move fouled equipment from one area to another.
* Drain all the water from your boat before you leave a sailing site, including any caught in buckets or sails, etc. Invasive species can remain alive for long periods (up to a week or more) if kept moist, so care should be taken over any area of a boat able to harbour moisture.
* Inspect and clean your trailer before and after use; always remove any visible plant, fish, animal matter and mud and put it in the bin.
* For boats kept in the water permanently, hull fouling is the main means of transfer. Clean your hull regularly to minimise the risk. Consider pulling your boat out if you don’t need it for a while.
* Try not to run through water plants and weed; this chops up the plants and can spread them further.
* Be aware of any additional signage or information on non-native species posted around water bodies.

If an invasive species is found to be present at your sailing club then it is important to contain the problem and prevent spread to other water bodies around the UK. There is usually no reason why recreational boating cannot continue in the event of an alien outbreak providing the following guidelines are adhered to:
* Inspect all boats leaving the lake and wash them down thoroughly with high pressure freshwater hoses; it is vital that no invasive species leave the site. If you are sailing Moths be aware that the trampoline can present a key problem area.
* Inspect all trailers leaving the site and wash them down with freshwater; the space between the wheels and the trims needs particular attention.
* All washdown water must be returned to the lake and NOT enter the sewerage / drainage system; this is essential to prevent spread through the waste water system.
* If dealing with a mobile invasive species, try to limit the amount of time dinghies and trollies spend in the shallows when being taken off the water; this will limit the opportunities for the alien species to attach to your kit.
If you think you have a problem with an alien species then please contact your local Environment Agency office for advice and send a photo to so that a record can be taken.

Further advice on how to limit the spread of non-native species around inland waters is available from the RYA and BMF funded environmental initiative The Green Blue (

(Article published 6th December 2010)

The Environment Agency (EA) has confirmed the identification of ‘Dikerogammarus villosus’ or the ‘killer shrimp’ in two more locations in the UK; Cardiff Bay and Eglwys Nunydd Reservoir in Port Talbot.

Given that the killer shrimp has now appeared in Wales it is really important that we boaters do our bit to limit any further spread around the country.

Corus Sailing Club at Port Talbot and the Cardiff Bay Yacht Club and Cardiff Yacht Club in Cardiff Bay are continuing to operate as normal however, all water users are making strenuous efforts to confine the problem and boats leaving the club premises are being washed down with freshwater first.

The RYA is fully supportive of the actions being taken by all affected clubs and would encourage all visitors to continue to enjoy the facilities available in both locations.

Since its discovery at Grafham Water earlier this year the RYA has been encouraging boaters to do everything they can to minimise the spread of these voracious invasive predators.

Although harmless to humans, the killer shrimp is particularly aggressive and preys on a range of invertebrates sometimes wiping out entire populations.

Non-native invasive species can be spread around the country in a number of ways including on the hulls of our boats and associated kit.

More information on the killer shrimp can be found at the Non Native Species Secretariat at the Department for Food and Rural Affairs.