Natura 2000 sites comprise an ecological network of protected areas designated for their important European habitats and species, through the European Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora 92/43/EEC ('Habitats Directive') and the Conservation of Wild Birds79/409/EEC ('Birds Directive').
These are Special Areas of Conservation (SACs) and Special Protection Areas (SPAs), respectively. The Conservation (Natural Habitats, & c.) Regulations 1994 transpose the Habitats Directive into UK law, and also apply to SPAs.
The aim of the Habitats Directive is to maintain the biodiversity of the Annex I and II habitats and species within a SAC at "favourable conservation status", taking into account the economic, social, cultural and regional requirements.
For each SAC, conservation objectives are proposed from which the management plans and monitoring programmes may be developed to maintain the site in favourable condition.
All SACs have to be assessed at least once every six years by Natural England (formerly English Nature). When designating the sites, attempts were made to keep them within SSSI boundaries, however, SACs can extend beyond Mean Low Water whereas SSSIs cannot be designated beyond the inter-tidal.
Under Regulation 33 (2) of the 'Habitats Directive', relevant authorities are expected to meet conservation objectives for the Natura 2000 sites through local management plans. The Regulations place a legal obligation on the UK government and its agencies:
International wetland sites are designated under the Ramsar Convention 1971, and there are several Ramsar sites around the Solent, including the Solent and Southampton Water Ramsar Site that qualifies :
Special Areas of Conservation (SACs) have been designated according to rare or threatened European Annex I and Annex II habitats and species listed in the Habitats Directive.
There are two SACs within the Solent, the Solent Maritime SAC and the Solent and Isle of Wight Lagoons SAC.
The Solent Maritime SAC qualifies on the basis of the following Annex I habitats:
The Solent and Isle of Wight Lagoons SAC contains a series of brackish lagoons located in the Pennington and Oxey marshes inland of the Lymington to Keyhaven seawall, and elsewhere such as at Gilkicker.
These coastal lagoons (created when original seawall/embankments were dug and constructed) are priority habitats in danger of disappearance, and are considered to be one of the best areas in the UK.
The Birds Directive refers to the preservation, maintenance and re-establishment of habitats in order to protect and support internationally important bird populations, through the designation of Special Protection Areas (SPAs). SPAs are classified for rare and vulnerable birds, listed in Annex I of the Birds Directive, and for regularly occurring migratory species.
The Solent and Southampton Water SPA qualifies, under the Birds Directive:
European Marine Sites are defined in the Habitats Regulations as any part of a European site (SAC, SPA) covered (continuously or intermittently) by tidal waters or any part of the sea up to the seaward limit of territorial waters.
The Habitats Directive is being implemented through a single Solent European Marine Sites (SEMS) Management Scheme for the Hampshire coast. The SEMS comprises a Special Area of Conservation and three special Protection Areas (but excludes Pagham Harbour).