What we offer

Greenlight Environmental Consultancy offers a wide range of services with respect to otter surveys, including:

  • Preliminary Ecological Appraisal (“PEA”) – This is an initial site assessment to identify habitats present on site that may support protected species. This includes a site visit and a desktop assessment. A PEA is typically required as a first step to address the ecological aspects of a planning application. The PEA would recommend if further otter surveys are necessary, and appropriate mitigation and enhancements for the proposed development.
  • Habitat suitability assessment – This type of survey helps to determine the likely presence of otters on a site from the habitat features recorded, and to assess the need for further surveys.
  • Presence/absence surveys – This involves a systematic search for evidence of otter presence along a watercourse. Signs of otter include spraints, holts, footprints, feeding remains, slides into water, and couches.
  • European Protected Species Mitigation Licences – In order to undertake development works which have no means to avoid harming the otters or damaging or blocking access to their habitats, a license will need to be granted by Natural England.
  • Installation of otter fencing – Otter-proof fences can be used to stop otters from going onto a development site.
  • Artificial holt creation – Constructing artificial holts can be a compensation measure to replace those that are expected to be damaged or removed.


The European otter Lutra lutra is part of the same family as badgers, weasels, stoats, pine marten and mink (Mustelidae). They live near water courses and rest in holts (burrows) which can be found in tree root systems, in holes on the bank, or under piles of rocks. They can also be found resting above the ground on couches, which are usually areas of flattened vegetation.

They are active at dusk and during the night but they may come out occasionally during the day. Their diet mainly consists of fish, frogs, birds, crustaceans and small mammals.

In England, otters breed throughout the year and usually have one to three cubs. They only breed once every two years because the cubs remain dependent on their mother for a year.

Otters have no main predator but their main threats result from human activities through the destruction of their habitats, from pesticides polluting watercourses, and from being run over by vehicles while crossing roads.


Otters are protected under UK and European Union (“EU”) laws. They are listed under:

Under these legislations it is an offence to:

  • Capturing, killing, injuring and disturbing;
  • Damaging or destroying breeding/resting places;
  • Obstructing access to resting places; and
  • Possessing, advertising for sale, selling or transporting for sale, live or dead (part or derivative).

In simple terms: all development proposals which have the potential to impact on local biodiversity, and Local Planning Authorities (“LPA”) require sufficient information to make informed decisions that wildlife can be protected from injury or disturbance during the development. They often require a Preliminary Ecological Appraisal (“PEA”), and further otter surveys if this species is likely to be present.

If otters are present on a site where proposed works are likely to cause disturbance or harm to otters and their habitat, a European protected species (“EPS”) licences and an appropriate mitigation strategy will be required in order to proceed with the works.


Otters live near undisturbed waters such as rivers, lakes, streams and occasionally ponds and ditches. The can also be found along the sea shore. They are territorial and their home range can range from 1-40km, depending on the density of food available.

Otters are not migratory and therefore live in their territories all year round.



Otter surveys can be conducting at any time of the year, but evidence such as paw prints is often easier to find during spring, before the vegetation establishes, and when water levels recede and wet mud is exposed. As otter activity can vary seasonally, several otter surveys may need to be conducted throughout the year to measure the impacts and assess the necessary mitigation measures. The number of otter surveys needed will vary according to the likeliness of impacts on otters from the proposed works and to the size of the proposed development.

Otter surveys (timings)

Mitigation and enhancements

Mitigation and enhancement measures for otters include creating a protection zones around otter resting places and on each side of watercourses, implanting a scheme to ensure the maintenance of an undisturbed and unpolluted watercourse, installing otter fencing near new roads, and creating artificial otter holts or couches.



Chanin, P. (2003), Ecology of the European Otter. Conserving Natura 2000 Rivers, Ecology Series No. 10. English Nature, Peterborough.

Natural England. (2014), Otters: surveys and mitigation for development projects