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Section 2: Managing non-native species

2.1: Surveying for non-native species

Surveys are vital to detect new non-native species at an early stage, before they establish and spread and become a significantly more costly problem. Surveys for early detection should be carefully designed and targeted to give usually a yes (present) or no (absent) answer for an area. Surveys may also be required to monitor progress of a management plan or to confirm absence of a species following an eradication programme.

There are three types of surveys to consider:

  1. General
  2. Site specific
  3. Species specific

General surveys

For large or conspicuous animals and plants this is a looking survey. Staff and the public should be encouraged to be vigilant and report new sightings. Interest groups such as botanical societies should also be encouraged to undertake specific searches for new emergent species.

Read more on how to record and report non-native species.

Site specific surveys

These are surveys targeted at key sites such as high value biodiversity areas or areas near high risk entry points. Surveys should extend beyond the entry point depending on the habitat, geography, tracks and roads around the entry point.

  • High risk entry points for terrestrial species: airports, seaports, and container or freight unpacking areas
  • High risk entry points for marine species: harbours

Species specific surveys

Where specific threats are identified and prioritised it will be appropriate to carry out regular surveys. It is important to consider frequency and timing of surveys.

Find identification guides for over 60 different non-native species.

Guidance on surveying for different groups

Vertebrates (site specific survey)

  • Search for signs such as tracks, droppings, feeding damage.
  • Know your fauna and look for new species.
  • Find out who the local experts and contact people are.
  • If you find a new species record it carefully, report it and ensure it is identified rapidly.

Mammals (species specific survey)

  • Surveying for large mammals such as deer, apart from sightings of the mammal look out for distinctive signs such as tracks and feeding damage. Annual or biennial surveys by a knowledgeable observer will suffice.
  • Surveying for smaller mammals such as rodents and feral cats needs to be seasonally timed, habitat selective, and more intensive as they are more difficult to detect in low numbers.

Also see the Tracking Mammals Partnership Guidelines on Best Practice in Surveillance and Monitoring (external link)

Insects (species specific survey)

  • Collaborate with local entomologists to design survey methods to suit the insect being surveyed.
  • Based the survey on specific behaviours and characteristics of the invader.
  • Make use of very specific effective trapping methods such as pheromone traps or targeted lure traps where possible.

Reptiles, lizards and snakes (species specific survey)

  • Trapping using rodents as bait in double compartment traps has been effective.
  • General survey and high level of public awareness is also important.

Freshwater fish and invertebrates (species specific survey)

  • The angling community can be very useful in detecting new fish introductions
  • Select fish and invertebrate sampling techniques according to habitat, depth of water and species sought.
  • Fish sampling techniques include gill nets, trawls, seine nets, rotenone, angling and electroshocking.
  • Invertebrate sampling techniques range from ponar grabs for benthic organisms to plankton tows for planktonic organisms.

Plants (site specific survey)

  • Use an experienced botanist who knows the area. This person should be able to readily identify a new arrival.
  • For people with less botanical experience use identification aids such as the ID sheets on this website. Also make use of books, field guides and posters.
  • Use posters of known prior invaders or invasive non-native species present in neighbouring areas or countries, easily transported species and species of similar bio-climatic zones to raise awareness and to educate.

Plants (species specific survey)

  • Use identification aids such as the ID sheets on this website, field guides, books and illustrations.
  • ID training may be necessary.

Marine species (site specific survey)

  • Organise a team of marine taxonomists (probably volunteering their time) to focus on examining dock fouling at a series of stations over a short period of time (e.g. one week).
  • Dock fouling can be quickly and effectively sampled without regard to the tide level.
  • Regular monitoring of this kind might be suitable following an eradication programme.

2.2: Management methods

There are four basic methods for controlling invasive non-native plant species:

  1. Mechanical– cultivation, hoeing, pulling, cutting, raking, dredging, or other methods to uproot or cut weeds.
  2. Chemical– Specific herbicides.
  3. Biological/Natural – Use of pests and diseases of the target weed to weaken it and prevent it from becoming a problem.
  4. Environmental– Altering the environment to make it less suitable for weed growth e.g. increasing or decreasing water velocity.  

Important: The use of herbicides in or near to rivers, canals, lakes and drainage channels in England and Wales requires prior agreement from the Environment Agency and the Scottish Environment Protection Agency (SEPA) in Scotland. Biosecurity must also be taken in to account.

Find links to good practice management information for a number of species here.

INNS Mapper 

The INNS Mapper app and website have been developed to help Local Action Groups and other organisations carrying out INNS management. Users can record where INNS management has taken place, along with sightings of 62 non-native species, both as individual sightings and as a survey carried out through the tool.

Disposal of plant waste

Correct disposal of plant material is vital to avoid the risk of spreading the problem further. Always contact the Environment Agency for England and Wales (Tel: 08708 506 506) and the Scottish Environment Protection Agency (SEPA) (Tel: 01786 457700) for advice on disposal because there are regulations which cover the composting, burning and burial of plant materials on-site and the transfer and disposal of material including ash to licensed or permitted landfill sites.

Most garden waste should be either composted or burned within the same garden. If this is not possible, the material should be disposed of by the local council, who should be informed if waste contains knotweed. Large volumes of waste requiring burial on-site may require a licence under the Pollution Prevention and Control Regulations 2002.

The 'Be Plant Wise' campaign advises how to dispose of garden plant waste responsibly.

Japanese Knotweed

Do not compost. Read more on controlling and disposing of Japanese knotweed (external link)


Failure to ensure safe, legal disposal or obtain an appropriate licence or exemption could result in prosecution. The information in these pages is covered by our disclaimer.

2.3: Health and safety, biosecurity and legislation

Health and safety issues to consider when starting a project

  1. Provision of a safety briefing to everyone working on the project.
  2. Suitable supervision
  3. The need to for a first aider with adequate equipment
  4. PAT testing of electric equipment
  5. Any need for CRB checks (eg if working with children) and child protection guidelines
  6. Correct Personal Protective Equipment (PPE), including consideration of the weather and time of year.
  7. Site specific risk assessment (including confined spaces)
  8. Up to date insurance (alone or with supervisor) and decide if cover for liability is needed or not
  9. Regularly updated medical records of volunteers,
  10. Contractor training certification

Useful information on health and safety

Water safety - how to avoid accidents (external link) (Environment Agency)
The Countryside Code - Respect, Protect, Enjoy (pdf) (Natural England)

It could be worth while for groups to investigate insurance cover for activities that are deemed to be dangerous.

Download Volunteer Health & Safety Cards ('Blue cards') for use during practical tasks. These cards were designed by the Source to Sea Project (Wiltshire Wildlife Trust) & kindly offered for use by all. They contain useful H&S information about the volunteers in case of emergency.


Biosecurity means taking steps to make sure that good hygiene practices are in place to reduce and minimise the risk of spreading invasive non-native species.  A good biosecurity routine is always essential, even if invasive non-native species are not always apparent.

Biosecurity should be considered at the earliest stage when planning any field work, from surveying an area to removing non-native species. Some biosecurity measures can be as simple and as quick as making sure footwear is clean.

Information on preventing the spread of non-native species and diseases when working or volunteering in the field: Biosecurity in the field. 

Free online biosecurity training for anyone working or volunteering in the field.


Find details of legislation relating to non-native species.