Habitat point records from 1987 Wood Flamborough Head sublittoral survey

Flamborough Headland is a Heritage Coast and SSSI, noted not only for its dramatic scenery and geological formations, but also for the colonies of seabirds that breed on the cliffs. It is the most northerly outcropping of coastal chalk in the British Isles, and the chalk extends into the subtidal zone, an area which prior to this study had not been investigated in detail. During August 1987, over a period of two weeks, 62 dives were made in the shallow sublittoral zone around the headland, from Speeton to Sewerby. Details of habitats and communities were collected at each site, and species checklists completed. The seabed around the headland is predominantly rocky and includes a wide range of features. Close inshore along much of the north and east facing parts of the headland, the chalk platforms are dissected to form outcrops and gullies, with vertical faces often 4 m in height, and sometimes up to 6 m. These formations lead to terraced bedrock where the 'steps' become progressively lower further from the shore, until a flattish bedrock plain is reached. Along the south facing side of the headland there are no large outcrops and the bedrock terraces are much lower. To the south-west the seabed becomes increasingly covered by small boulders, cobbles and pebbles. There are also patches of silty sand. The algal-dominated (infralittoral) zone extended to a depth of about 6 m below Chart Datum on upward-facing surfaces. In the north and east, kelp Laminaria hyperborea forests were present to a depth of about 3 - 4 m below Chart Datum, with red algae contributing to the undergrowth, and extending into deeper water. Sessile animals occurred with the algae, but were particularly prominent on steep, vertical or underhanging faces of the outcrops. Wave action is considerable along the north and east facing coastline, and some areas of shallow low-lying bedrock (especially gully bottoms) supported only a few scour-resistant species. On the south facing side, L. hyperborea was largely replaced by L. saccharina, again with red algae present. The deeper animal-dominated (circalittoral) zone supported a wide range of sessile organisms. Robust hydroids and bryozoans able to withstand strong tidal streams and sand scour were dominant, but also present were colonial tunicates, dead-man's fingers Alcyonium digitatum, and other sessile organisms. In general the most prominant mobile animals were decapod crustaceans, starfishes and brittlestars. The population density of sea-urchins Echinus esculentus and fishes appeared to be relatively low. Several 'boring' species were widespread and abundant, including the bivalve molluscs Hiatella arctica and Zirphaea crispata, the small polychaete worm Polydora ciliata, and the sponge Cliona celata (non-massive form). The shallow sublittoral around the headland is of biological interest because of the range of habitats, communities and species present. Many of the species found at Flamborough occur off all coasts of the British Isles, while several have a northerly distribution. However, a significant number are southern species, some of which are apparently little known from the east coast or from other areas of sublittoral chalk. Apart from these attributes, the area also supports an important local fishery, and is a popular dive site. A useful first step towards safeguarding the Flamborough Head marine environment and its wildlife is to stimulate interest amongst visitors and users. It is recommended that consideration is given to employing a specialist marine ranger or warden within the Heritage Coast project who would be responsible for promoting these aspects, including the production of relevant interpretive material. It is also suggested that a sublittoral study site is established, where the habitats and communities can be investigated in detail and changes monitored. The Marine Conservation Society is in an ideal position and has the specialist knowledge to coordinate a project such as this, which should not only provide useful information, but also act as an interesting focus for those who dive the area. Records currently considered sensitive have been removed from this dataset.

Organization: Joint Nature Conservation Committee