Invasive Non-native species

We are always looking out for new invasive species, and some ‘alert’ species need a rapid response.

Alert species are as follows

Please ensure that you report these species as soon as possible. You can send an e-mail with a photo and location to:

The general public, landowners and professionals have reported 32 different species of invasive plants and animals in Suffolk and Essex.  Invasive species are species that are not normally found in the UK and have escaped from captivity or been released and possibly spread around by people. They have a negative impact on our environment (eliminating native species), our health and even damaging buildings. The most common species reported is American mink Neovison vison, followed by Himalayan balsam Impatiens glandifera and Japanese knotweed Fallopia japonica.

Some of these invasive species are really problematic and there are no effective control methods . For example, American signal crayfish Pacifastacus leniusculus preys on our native white-clawed crayfish as well as killing it through a disease it carries.  Another example is New Zealand pygmyweed Crassula helmsii, it forms dense carpets over ponds and lakes, growing over native plants. When control is possible, for example on Japanese knotweed, it must be carried out over several years and costs a large amount of money. It is estimated that invasive species cost the UK economy £1.7 billion each year.

It is far more cost effective to prevent an invasive species spreading into the wild in the first place. Make sure that you don’t spread invasive species by following our CHECK, CLEAN & DRY campaign, see . Also choose native plants to grow in your garden and do not dump plants in the wild, for more information see:

It is best to control an invasive species early before it becomes established so early reporting is key. There are several applications that you can use to report these sightings, either on the web or using an android phone.

Or you can do it the old fashioned way and report it to your local Biological Records Centre. For records in Essex see  and in Suffolk see

Please note that it is an offence allow certain invasive plants and animals to escape in the wild and to sell certain invasive plants under the Wildlife and Countryside Act (1981) as amended. (See legislation for exact phraseology).

With grateful thanks to Amy Prendergast, Environment Agency

One response to “Invasive Non-native species

  1. Pingback: Invasive non-native info page added | Essex and Suffolk Rivers Trust·

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