There are several hundred 'priority' invertebrate species in the UK. Whilst these species are not necessarily strictly protected (several are however legally protected), government policy is that planning authorities should consider these species when determining planning applications.

Implications for Development

It is good practice, especially for EIA developments, to consider invertebrates within the scheme. Rare invertebrate species, and rich or diverse assemblages of invertebrates can occur on development sites e.g. brownfield sites. The value of a site for invertebrates therefore usually considered in the ecologist's assessment.

Survey Methods

Where a Preliminary Ecological Appraisal indicates that potentially good quality habitat for invertebrates is present, or important invertebrates have been recorded locally, the ecologist may recommend invertebrate surveys. Invertebrate surveys are usually possible between March and October. Survey techniques typically involve sweep nets, beating trays, pond nets, pitfall traps and light traps.

Mitigation & Compensation

Mitigation or compensation for invertebrates is generally habitat-based as it is usually impractical to mitigate the loss of individual invertebrates. It is best to design the site layout such that key invertebrate habitat is retained, keeping uncommon invertebrates in situ. If the existing habitats cannot be retained then compensatory habitats that are designed with invertebrates in mind can be created elsewhere. Ideally this would be in place before the existing habitat is lost so that there is always appropriate habitat present.

Capture and removal of invertebrate species from development sites is occasionally required if a strictly protected species is present on-site. Capture methods would depend on the target species and would require a licence from Natural England. The receptor site would need to provide the right conditions for the species in order for translocation to be successful.

Entomologist collecting insects using a sweep net
Glow worm Lampyris noctiluca