Disturbance and increased visitor pressure impacts on internationally designated sites

Disturbance and increased visitor pressure impacts on internationally designated sites

Internationally designated sites such as Special Protection Areas (SPAs), Special Areas of Conservation (SACs) and Ramsar Sites can have ramifications for development and other activities a long way beyond their immediate boundaries. Where these sites might be affected, impact assessment and decision making is sometimes highly precautionary, meaning that activities many miles removed from these sites can and do come under the closest scrutiny.

An example of this is the consideration of recreation and disturbance impacts on habitats and species, and in particular on important bird populations. We have seen an increase in statutory consultees seeking mitigation for recreational impacts, and we are also seeing an increase in the amount of policy that supports such requests.

The presence of internationally designated sites can lead to planning authorities undertaking an “appropriate assessment” of proposals, to assess in detail the likely effect on the special interest of the sites. On some of the sites that we have been involved in it has been necessary to undertake visitor surveys alongside our more regular ecological survey, in order to establish a baseline of visitor and visitor impact data.

Our work on these issues is commonly in response to concerns at sites that are made up of a number of separate component parts, often spread over a large area. This can make realistic assessment a very complex process and it is crucial that surveys are designed in such a way that they capture the most useful data. Typical sites of this type that we have worked on include the Thames Basin Heaths SPA, Dorset Heaths SPA, Upper Nene Valley Gravel Pits SPA, and South Hams SAC. Similar issues also arise on “single location” sites, and we have reviewed or carried out assessments of visitor impacts on the following sites:

  • Portsmouth Harbour SPA
  • Orton Pit SAC in Peterborough
  • Lydden, Temple and Ewell Down SAC in Dover
  • Berwickshire and North Northumberland Coast SAC
  • Tweed Estuary SAC
  • Lindisfarne SPA
  • Northumberland Shore SPA
  • Northumbria Coast SPA
  • North Northumberland Dunes SAC


Our experience of assessing disturbance from development suggests to us that the issue of visitor pressure is increasing in importance for new development – sometimes even at some distance from internationally designated sites. In some instances it is possible to address this through site design, protection and management measures. However, when the issue is a potential contribution to the existing level of visitor pressure on internationally important sites, it is important to recognise that baseline information on visitors and their effects will not always be available. Without this baseline it is very difficult to make a proper assessment of likely impacts, and this alone could threaten the success of a development proposal. The requirement for visitor surveys should be determined at an early stage as survey design and timing is crucial to success: some surveys are seasonal (for instance, winter for impacts on wintering birds, or spring for breeding birds). These sorts of considerations can have significant implications for a development programme.

In the attached article, Dr Peter Shepherd and Steven Betts review in more detail some of the policies and thinking behind disturbance effects on wildlife. They also review the range of important impacts and what can be done about them, and illustrate this through three case-studies.

Read the article here: BSG Disturbance Paper 2012

For further information about international sites, disturbance effects and our work on visitor studies, please feel free to contact Dr Peter Shepherd, Steven Betts or Owain Gabb.

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