Introduction

Alien, invasive species are a problem all over the world and Essex is no different. The problem and the way that Essex Biodiversity Project is tackling the issue is described below. To learn more about invasive species, see the Further Information section, the Plantlife website is particularly recommended.

What are alien, invasive species?
 

The problem of non-native species in Essex

Many alien, invasive species have been recorded in Essex. For example, Japanese Knotweed has been found in several sites around Colchester and Brentwood, Himalayan Balsam on at least 35 river banks in NE Essex and Signal Crayfish in the River Stour. Muntjac deer are present throughout the county and the increasing numbers are having a significant impact in many of our woodlands. 

Large numbers of muntjac can have an adverse effect on woodland vegetation because they browse on herbs, shrubs and young trees, which results in a change in the vertical structure of the woodland. These deer reduce the height of low growing shrubs, such as heather Calluna vulgaris, and prevent taller species, such as hazel Corylus avellana, from reaching their full height. This results in woodlands with a ground layer and a high canopy, but a sparse middle layer. The food and egg-laying plants of butterflies and other invertebrates, such as snails, may be destroyed, thus reducing the diversity of the woodland and affecting birds and mammals by removing food sources.

In many cases, little is known about distribution of these invasive species. The Essex Biodiversity Project has coordinated a group to tackle this increasingly important local problem. The group is comprised of Peter Spurrier, chair (Essex County Council), Andy May and Kate Hayward (Essex Wildlife Trust), Charlie Williams (Natural England), Paul Charlton (RSPB), Julia Stansfield and Rebecca O'Shea (Environment Agency), Dave Bigden (Consultant Countryside Manager) and Gen Broad (Essex Biodiversity Project).

How do alien invasive species get into the countryside?

These species may arrive by accident, for example, deer escaped from deer parks, or they may be released by design, for example, planting Spanish bluebells rather than native bluebells in woods and mink released intentionally from fur farms. You can help by:

• composting garden plants rather than disposing of them in the countryside
• not releasing non-native garden or aquarium plants into the wild
• buying native stock - aquatic species, wildflowers, trees and shrubs
• not releasing non-native fish into ponds, streams or rivers
• not releasing non-native amphibians or reptiles into the countryside
   

What are we doing about the problem?

We aim to identify the alien, invasive species causing most damage in Essex, together with their distribution throughout the county. We will then produce guidance on appropriate control measures and identify resources, such as funding for control and organisations providing information and advice for the public.

This page is being updated as the project progresses - watch for further updates!

What you can do to help

If you see any of the following non-native, invasive species, tell us where you see them and approximately how many you see. If possible, please use a full Ordanance Survey grid reference (2 characters, 10 digits).

We will use this information to produce maps showing the locations of sightings in Essex. When completed, these location maps will be available on this website. This information will be of help to researchers, both within Essex and on a national scale. We are collaborating with Plantlife on their 'Alien Invasives' campaign and will share all records with them.

High risk species (causing the greatest damage)

Low or medium risk species (causing less damage)