1.2. Habitats and species of European Interest in the UK

1.2.1 Habitat types of European interest

Annex I of the Directive (as amended by the 2003 Treaty of Accession) comprises a list of 189 habitat types. Member States must consider designation of SACs for each of the features which occurs in their European territory.

Of these habitat types, 78 are believed to occur in the UK (excluding Gibraltar), based on the descriptions in the Interpretation manual of European habitats (European Commission DG Environment 2003). A full list of these is provided. As discussed later, the habitat types are very variable in the range of ecological variation they encompass. Some are very narrowly defined, comprising a single vegetation type and are analogous to single associations as described using traditional phytosociological techniques; others are large units defined on a physiographic basis, such as 1130 Estuaries, encompassing complex mosaics of habitats and correspond approximately to the 'Broad Habitats' and/or 'Priority Habitats' of the UK Biodiversity Action Plan (Jackson 2000).

A sub-set of the Annex I habitat types are defined as being 'priority' because they are considered to be particularly vulnerable and are mainly, or exclusively, found within the European Union (Article 1d). The importance of these priority habitat types is emphasised at several places in the Directive (Articles 4 and 5 and Annex III), not only in terms of the selection of sites, but also in the measures required for site protection (Article 6) and surveillance (Article 11).

Of the 76 Annex I habitat types that are known to occur in mainland UK, 23 are defined as priority habitat types (Table 1.1).

Table 1.1 Annex I priority habitats known to occur in the UK

There has been considerable debate about the occurrence of some Annex I habitats in the UK. Habitats which it has been suggested might be present in the UK include 1410 Mediterranean salt meadows (Juncetalia maritimi), 2180 Wooded dunes of the Atlantic, Continental and Boreal region, and 3270 Muddy river banks with Chenopodium rubri p.p. and Bidention p.p. vegetation. However, following scrutiny of phytosociological literature and discussion with specialists in other Member States, none of these habitats is now considered to occur in the UK.

1.2.1.1 Offshore habitats
The Directive is now being implemented in UK offshore waters (see Section 1.6.4). Three Annex I habitats, 1110 Sandbanks which are slightly covered by seawater all the time, 1170 Reefs and 1180 Submarine structures made by leaking gases, are known to occur in the UK Offshore area. In addition, 8330 Submerged or partially submerged sea caves may also occur offshore (JNCC 2000).

Annex I habitat types which are or may be found in the UK offshore waters are listed in Table 1.2. However, it should be noted that the distribution and abundance of many habitat types within Europe are even less well understood in the offshore area than they are on land or in inshore waters. Some features present in UK waters may be regional variants or possibly degraded examples of the Annex I type, for example the 'pockmarks' primarily found in the North Sea, with smaller examples elsewhere, which represent 1180 Submarine structures made by leaking gases.

Table 1.2 Annex I habitat types relevant to the UK offshore area