Pembrokeshire Marine/ Sir Benfro Forol

General site character

• Marine areas, Sea inlets (96%)
  
• Tidal rivers, Estuaries, Mud flats, Sand flats, Lagoons (including saltwork basins) (3.8%)
  
• Salt marshes, Salt pastures, Salt steppes (0.2%)
  

Annex I habitats that are a primary reason for selection of this site

• 1130 Estuaries

  Pembrokeshire Marine includes the Daugleddau estuary, a ria estuary in south-west Wales, formed in the upper reaches of one of the best examples of a ria in the UK. Associated with the wide range of environmental conditions, particularly seabed substrates, tidal streams and salinity gradients, there is a wide diversity of communities and species. The species-richness of sediment communities throughout Milford Haven and the Daugleddau is high. Tide-swept sponge communities on shell/cobble substrates and bedrock in the upper reaches of the Daugleddau are exceptional in their diversity. The site also includes smaller estuaries entering the Daugleddau and Milford Haven, and wide intertidal mudflats with rich and productive invertebrate annelid and mollusc communities, occurring in ‘pills’ (creeks).

• 1160 Large shallow inlets and bays

  Pembrokeshire Marine in south-west Wales includes Milford Haven, one of the best examples of a ria in the UK, and the wide, shallow, predominantly sandy embayment of St Brides Bay. The wide range of environmental conditions, particularly seabed substrates, tidal streams and salinity gradients, supports high community and species diversity. The species-richness of sediment communities throughout Milford Haven is particularly high, with intertidal sandy/muddy areas supporting extensive beds of narrow-leaved eelgrass Zostera angustifolia. High-salinity water and rocky substrates penetrate far upstream, and communities characteristic of fully saline conditions occur. A wide range of subtidal and intertidal rocky habitats are present, from rocky reefs and boulders to rich underboulders, crevices, overhangs and pools.

• 1170 Reefs

  Reefs in this south-west Wales site are largely composed of igneous rock but include areas of more friable Old Red Sandstone and some limestone. Extensive areas of sublittoral rocky reef stretch offshore from the west Pembrokeshire coast and between the Pembrokeshire islands and many small rocky islets. Limestone reefs occur in the south of the site. Reefs also extend through Milford Haven and into the variable salinity conditions of the Daugleddau estuary. Reefs within the site are subject to an exceptional variation in strength of tidal streams and wave exposure. The highly variable rocky seabed topography, together with the indented coastline and extreme tidal range, cause strong tidal streams, particularly around headlands, through sounds and in tidal inlets. The shallower and south-west-facing rocky reefs are exposed to severe wave action, while many others are extremely wave-sheltered. Many of the reefs extend onto the shore and provide examples of both the most exposed and the most sheltered intertidal rock communities in southern Britain. Reef habitat diversity is increased by caves, tunnels and surge gullies in both subtidal and intertidal zones. The wide variation in exposure to water movement, the range of rock type, slope, aspect and topography, and the high water quality, together with local exposure to abrasion from adjacent sediments and reduced salinity in the Daugleddau, are reflected in the wide diversity and species abundance of biological communities. Offshore there are particularly extensive areas of tide-swept kelp and species-rich red algal populations and, across the large areas of deeper rock reef, a wide range and abundance of invertebrate animal communities, with hydroid, bryozoan, soft coral and anemone species. More sheltered reefs, including those in lowered salinity and higher turbidity, typically support diverse and species-rich sponge- and ascidian-dominated communities.

Annex I habitats present as a qualifying feature, but not a primary reason for selection of this site

• 1110 Sandbanks which are slightly covered by sea water all the time
• 1140 Mudflats and sandflats not covered by seawater at low tide
• 1150 Coastal lagoons  * Priority feature
• 1330 Atlantic salt meadows (Glauco-Puccinellietalia maritimae)
• 8330 Submerged or partially submerged sea caves

Annex II species that are a primary reason for selection of this site

• 1364 Grey seal Halichoerus grypus

  Pembrokeshire in south-west Wales is representative of grey seal Halichoerus grypus colonies in the south-western part of the breeding range in the UK. It is the largest breeding colony on the west coast south of the Solway Firth, representing over 2% of annual UK pup production.

• 1441 Shore dock Rumex rupestris

  Habitat occurrence description not yet available.

Annex II species present as a qualifying feature, but not a primary reason for site selection

• 1095 Sea lamprey Petromyzon marinus
• 1099 River lamprey Lampetra fluviatilis
• 1102 Allis shad Alosa alosa
• 1103 Twaite shad Alosa fallax
• 1355 Otter Lutra lutra