EUNIS ( the European Nature Information System of the European Environment Agency (EEA)) offers a different, more specified, text: ‘Plant and animal communities as the characterising elements of the biotic environment, together with abiotic factors (soil, climate, water availability and quality, and others), operating together at a particular scale.’ A substantial literature exists on the definition of ‘habitat’ and related concepts, such as ecotope or biotope (e.g. Klijn, 1994). Moss & Wyatt (1994) simply synonimise biotope to habitat in a paper describing the CORINE effort to create a harmonised European habitat classification and database. This CORINE classification is presently succeeded by the EUNIS habitat classification, which is substantially more comprehensive (Figure 2(a)).

A substantial number of coastal habitats has been formally defined in the Habitat Directive (directive 92/43/EEC). The EUCC has arranged them according to their abundance in various European coastal landscapes, since some habitats are ubiquitous and others have a restricted occurrence (http://www.coastalguide.org/typology). Different coastal landscape types have been identified on the basis of predominant substrate, slope and prevailing tidal regime (Table 2(a)). These serve as a landscape typology over which the habitat typology is cross-tabulated (Table 2(b)).