This report describes the range of sublittoral habitats and communities of plants and animals encountered during surveys along approximately 15 km of coastline from Solva to Dinas Head along the mainland coast of North Pembrokeshire. Thirty-two sites were surveyed. The results are presented as descriptions of the species composition of the main communities encountered and an annotated species list. A wide range of habitats and communities were present along the coastline studies particularly in relation to the degree of exposure of different areas to wave action and tidal streams. The habitats and communities present in Abereiddy Quarry are unique to south-west Britain and there is only one other known location with similar attributes in Britain. The conservation status and scientific interest of sites is discussed. The region of Abereiddy from Porth-y-Dwfr to Porthlynnon including the offshore reefs and the quarry are seen as including a wide range of scientifically interesting habitats and communities within a fairly small area.
