SUSSEX MARINE SITES OF NATURE CONSERVATION IMPORTANCE

Site: The Waldrons reef						Ref. No. 5
Location: 3-5 km SE of Bognor					Other conservation designation?: No
Lat./Long. position of centre of site: 50° 45' 5" N  0° 38' 10" W			OS grid ref. of centre of site: SZ 962 955			Author: Robert Irving
Sea bed type: Sandstone reef with large boulders.			Depth range (below chart datum): 4-11 m			Date identified: November 1995

Summary

The Waldrons reef covers an extensive area of sandstone bedrock outcrops which occur in shallow to medium depths off Bognor. There are also large sandstone boulders, some rounded and others angular, with areas of cobbles, pebbles, gravel and sand in between. The approximate location of the reef is marked by two crescent shapes on the chart, indicating the 5 m depth contour. The rock has eroded to form many fissures, crevices, overhangs and variously shaped holes. The site is regarded as portraying many features of sandstone reefs.

Jumbled masses of large angular boulders can be found in certain areas, providing a range of horizontal, vertical and undercut surfaces. These boulders, known as 'sarcens', have a debatable origin: one theory is that they were deposited as drift-ice melted during a glacial phase; another that they are discarded ballast stones from early shipping.

Biological Description

Much of the sandstone bedrock has a covering of encrusting pink calcareous algae (Phymatolithon sp. and/or Lithothamnia sp.). The uppermost surfaces are dominated by foliaceous algae with sparse, stunted kelp plants Laminaria hyperborea and L. digitata. Common red algae include Delesseria sanguinea, Calliblepharis ciliata and Plocamium cartilagineum. Sponges are the most conspicuous component of the attached fauna, especially in shaded areas on vertical rock. Indeed the site is particularly rich in sponges with 24 species being recorded on the Sussex Sublittoral Survey (Wood 1984). Common species include Esperiopsis fucorum, Dysidea fragilis and Hemimycale columella. Rarities include the black tar sponge Dercitus bucklandi. Other conspicuous attached species include the soft coral Alcyonium digitatum, the hydroid Tubularia indivisa, white anemones Actinothoe sphyrodeta, various sea squirts and the tube worm Bispira volutacornis. In other respects, the variety of invertebrates recorded from the site is poorer than one might expect. A number of crustacean species are common including lobster Homarus gammarus, edible crabs Cancer pagurus, velvet swimming crabs Necora puber and spider crabs Maja squinado, the area being heavily potted. Cuttlefish Sepia officinalis have been seen by divers on numerous occasions. Common fishes seen close to the reef include ballan wrasse Labrus bergylta, goldsinny Ctenolabrus rupestris and tompot blennies Blennius gattorugine.

Between the formations of bedrock reef and boulders are areas of mixed sediment, with cobbles, pebbles, gravel and sand in varying proportions. Here may be found burrowing anemones such as Cereus pedunculatus and Urticina felina, chains of slipper limpets Crepidula fornicata, tufts of the bryozoan Flustra foliacea, stalked sea squirts Styela clava and hermit crabs Pagurus bernhardus. Common fishes include the dogfish Scyliorhinus canicula, dragonet Callionymus lyra and plaice Pleuronectes platessa.

References: Irving, R. A. 1994. Report of the West Sussex Seasearch Project, 1992-1993: Chichester Harbour to Littlehampton Unpublished Report, Coldwaltham, West Sussex McDonald, K. 1985. Dive Sussex - A Diver Guide Underwater World Publications, London Wood, C. (ed) 1984. Sussex Sublittoral Survey: Selsey Bill to Beachy Head Marine Conservation Society, SE Branch

Sussex SEASEARCH dive nos.: 92/01-16; 93/60-63a&b

Sussex Sublittoral Survey site no.: 10

Site Location

Diagrammatic representation of site: The Waldrons reef