Habitat point records from 1979 SWBSS Tintagel Head to the Devon border survey

This report describes the range of sublittoral habitats and communities of plants and animals encountered during surveys along the 45 km of coast from Tintagel Head to the Devon border. The survey was carried out over six days by two zoologists, one botanist and a post-graduate assistant. Sites were chosen by inspection of maps and charts to include locations exposed to different enviromental conditions. Checklists were used throughout survey and recording, photographs of different habitats and species were taken. Seventeen sites were surveyed. The results are presented as lists and descriptions of the species present in the main communities and an annotated species list. The area of seabed dominated by algae extended into deep water compared to most other areas surveyed in south-west Britain and no sites were studied where algae were absent. Communities of algae and animals characteristic of the main depth zones and similar to those present in other parts of south-west Britain were present at many sites. However, at some locations a distinct infralittoral fringe was absent and at several sites the kelp forest was absent. Distinctive communities, other than those at different depths on sand-free upfacing rock, were identified from sandy rocks, vertical and overhanging rocks, scoured rocks and unstable substrata. The communities present and the extent of depth zones were different to the north of Bude compared with areas to the south. The large extent of rock suitable for colonisation by algae and the variety of other habitats present resulted in a wide variety of algae and algal communities being recorded. However, the domination of most nearshore rock by algae and the low diversity of habitats not dominated by algae, led to the recording of only a small range of animal species and communities. The presence of large amounts of sand on and adjacent to rocks had considerable effects on the communities present along the coast studied. Sand scour and sand cover are considered to be important to both the absence of kelp forest from many sites and the development of communities of algal species able to withstand scour and smothering or fast-growing during summer when scour is reduced. Several algae and animals recorded during the present survey are near to the northern limits of their distribution. However, some southern or oceanic animal species present further north were not encountered along the coast studied and others were recorded in only small amounts, a feature most likely resulting from both the domination of algae in the areas studied and the absence of sheltered deep habitats. The area is considered particularly interesting because of the extensive algal-dominated communities and the distinctive communities present on sand-covered rock. Several rare or unusual species were also found, but this has to be balanced against the absence or small amount of many southern or oceanic species present in abundance further north. The Boscastle area is identified here as including a fairly wide range of scientifically interesting habitats, probably representative of this part of the Cornish coast.