None-native species

Marine invasive Non-native species

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The Cornish coast is under increasing pressure from the introduction of invasive non-native species.

Find out what they are and how you can help to prevent their spread

Non-native (alien) species are plants and animals which have been transported to regions beyond their natural range, usually by human activities. Once a species arrives in a new location, several things can happen; it can find its new habitat inhospitable and die off, it can survive with little environmental impact, or it may thrive and can become invasive.

Non-native species often arrive without their natural predators which would have kept them in check within their native range. Some display traits which allow them to out-compete native species for essential resources such as food, space and light. This may be by their being bigger and stronger, more vigorous and quicker to grow, or by breeding at a time which is advantageous over native species. Some species also directly prey on native wildlife and/or can carry diseases from which native species have no immunity.

How do they get here?
Plant and animal species have always used the oceans to move about the globe, but with the rapid expansion of global transportation over recent years, an increasing number of marine ecosystems are being compromised and restructured by non-native species. Human activities are lending a helping hand to these stowaways and hitch-hikers, transporting them unwittingly between water bodies on boat hulls, in ballast and bilge waters, and on water sports equipment and clothing. They have also been introduced through certain commercial practices, including the seafood and exotic pet trades and on the seed stock for aquaculture. Their journey may have begun in a far-flung place but once here, Cornwall’s thriving recreational and commercial maritime activities provide ample opportunities for marine invaders to arrive and spread. In fact, here are a few of the ones that are already here!

Slipper limpets: were introduced from North America and occur in high densities, fouling shellfish beds.

Wireweed: a fast-growing seaweed from the Pacific which out-competes native species. The dense growth is a nuisance to both swimmers and boats, entangling propellers and clogging engines.

Leathery sea squirt: transported from Korea, it is a fouling pest on ships hulls and oyster beds, out-competing native species for essential resources.

Combating Invasive Species. Since each invasive species can be so different, different approaches are often needed to tackle each one. This can be extremely troublesome and costly in an aquatic environment. There is, therefore, a growing need to build better systems by which to detect, monitor and control invasive species.  Early detection of new arrivals can save money and prevent them from spreading further. If you are a water-user you may, unknowingly be helping to spread invasive species from one water body to another via equipment, shoes or clothing. Help to stop this from happening by following these three simple steps:

Check that you’re not carrying living organisms

Check all your equipment and clothing for living organisms

Pay particular attention to areas which are damp and hard to inspect.

Clean all equipment, clothing and shoes

Clean and wash all equipment, footwear and clothes thoroughly

If you do come across any organisms, leave them at the water body where you found them.

Dry equipment and clothing carefully

Dry all equipment and clothing – some species can live for many days in moist conditions.

Make sure that you don’t transfer water elsewhere and remember to report any sightings to your local environmental records centre!

You can play an important role in helping to prevent the spread of non-native invasive species, find out how, including help with identifying and reporting, by visiting ww.erccis.org.uk/marineinvasives