Great Crested Newt Mitigation Guidelines

The principal document underpinning best practice regarding great crested newt survey and mitigation is the now rather dated 2001 publication by English Nature - the great crested newt mitigation guidelines, as well as the standard Standing Advice from Natural England.

A copy of the 2001 guidelines, together with other useful information on newt protection, can be downloaded at the following UK Government website link: https://www.gov.uk/great-crested-newts-protection-surveys-and-licences

Survey techniques and timings

‘Conventional’ surveys

The great crested newt mitigation guidelines dictate that since breeding takes place from around March to June, the survey season should reflect this. The guidelines describe great crested newt survey techniques such as bottle trapping, torch inspections and searches for eggs on leaves of suitable water plants. The requirements are as follows:

  • to check for presence of newts and if present;
  • to determine population size
  • Presence / likely absence: four survey sessions using three techniques (e.g. bottle-trapping, egg searches and torch counts) during the period mid-March-mid June, with at least two of these sessions being between mid-April and mid-May.
  • Status (population size): two further sessions (making a total of six in all) using three techniques, with one session taking place between mid-April and mid-May.

Mitigation options

The great crested newt mitigation guidelines also describe suitable options for mitigation to protect newt populations in the event that a development would affect their ponds or terrestrial habitats. General principles, in the event that great crested newts are likely to be a constraint at a proposed development site, would be as follows:

  • If great crested newts are found in ponds surrounding or within a development site, and if suitable terrestrial habitat is present which would be affected by the development proposal, then some mitigation for loss of habitat would be required. This is normally via trapping and translocation of newts to an enhanced (nearby) receptor site, coupled with new habitat creation or enhancement prior to translocation.
  • Site design (master planning) must also take newts into account in order to ensure that a high degree of landscape connectivity to undeveloped land can be maintained. This is so that the larger genetic population (known as a ‘metapopulation’) can continue to function normally.
  • Trapping and translocation is normally undertaken under a European protected species licence, which is applied for once full planning consent has been obtained. The licence application process can be time-consuming and requires an accompanying ‘method statement’, which must be acceptable to Natural England’s Wildlife Licensing Unit. The method statement describes how the newt population would be protected post-development.

More recent survey techniques: e-DNA

The great crested newt mitigation guidelines were published in 2001 and the technique of Environmental DNA (eDNA) testing had not been development at that time.

The eDNA methodology has now been approved for use by Natural England for presence / absence surveys in support of planning applications. However, since this is a new technique there is still some uncertainty about how it should be applied in the field. There are also limitations to its use; for example in the event of newts being confirmed as present in a pond, six conventional great crested newt survey sessions are still required in order to determine population size (and thus provide support for a European protected species licence).

An e-DNA survey is based upon the principle of testing for the presence of great crested newt DNA in water. DNA is detectable using a standard test which can only be carried out by specialist laboratories.

In order for the survey to be valid the work can only be undertaken between 15 April and 30 June. Although sample analysis can take up to several weeks, only a single survey visit is needed, so (at least in theory) eDNA survey has potential to considerably reduce survey effort and costs.

There are a number of technical and methodological limitations to the technique, which must be borne in mind at the survey design stage:

  • Sampling outside 15 April to the end of June can show presence, but it cannot be relied upon to establish absence and is therefore of limited use in a planning context.
  • Test results may not be conclusive - in particular since the technique relies upon surveyors being able to access several points around each pond. Difficult access may preclude effective survey and thus may nullify the results.
  • Unfortunately - and importantly - it is not possible to determine population size through this test and as a result a conventional survey using bottle trapping and other manual methods is likely to be needed if e-DNA provides evidence of presence. Given that population size information is needed to underpin development licensing, this is an important consideration.

Newt protection: Your questions answered

We can answer any questions you may have about the Great Crested Newt Mitigation Guidelines and newt protection. Call us on 01392 833345 or email info@amecology.co.uk.