Site selection process

The challenge of the marine environment

Identifying important sites for birds in the marine environment is challenging. It is difficult to collect good quality information on the ecology of birds at sea, due to the logistical and financial implications of collecting data within the vast extent of UK waters.

Marine bird distributions often show strong associations with habitat features, such as the distribution of their prey, other birds and/or marine mammals, as well as physical and/or biological processes and features. Habitat boundaries are often not visible, may be much more dynamic, both spatially and temporally, than those on land, and may extend across small to very large scales.

Consequently, it can be extremely difficult to define discrete sites, to estimate bird numbers within them, and thereby assess their relative or absolute importance to bird populations. JNCC is working with the country conservation agencies to find the best approaches for overcoming these issues and to ensure that common standards are adopted throughout the UK.


Stroud et al. 2001SPA site selection guidelines

Guidelines for the establishment of SPAs in the marine environment have been kept consistent with the established guidelines for the terrestrial environment, which were formulated with the overall aim of achieving ecological coherence of the SPA and wider Natura networks as a whole.

The UK SPA site selection guidelines follow a two stage process based on population thresholds and ecological judgements. In accordance with the Birds Directive, JNCC’s advice on the selection of marine SPAs is founded upon ornithological criteria only - socioeconomic, management, or political considerations are not applied.

Further reading:


Species being considered

A list of 44 marine birds for which marine SPAs in the UK are being considered has been compiled by JNCC. These include divers, grebes, several seaduck, and almost all seabirds (black guillemot is neither listed on Annex I, nor considered a migratory species in the UK). Sites for these species are currently being considered within four main types of marine SPA.

Most of these species are reliant on terrestrial environments at some stage in their life cycle. As such, their presence in an SPA (as a qualifying interest feature) alone does not signify that this site is a marine SPA. Conversely, some 'terrestrial' species are dependent on the marine environment for part of their lifecycle. For more information, see SPAs with marine components.


Common eider in flight (B Dean)