SUSSEX MARINE SITES OF NATURE CONSERVATION IMPORTANCE

Site: H.M.S. Northcoates						Ref. No. 7
Location: 14 km south of Bognor					Other conservation designation?: No
Lat./Long. position of centre of site: 50° 39' 71" N  0° 35' 40" W			OS grid ref. of centre of site: SZ 996 857			Author: Robert Irving
Sea bed type: Steel wreckage in deep water.			Depth range (below chart datum): 20-26 m			Date identified: November 1995

Summary

H.M.S. 'Northcoates' (known to many divers simply as the 'Armed Trawler') was a 277 ton trawler built in 1918 which, after 20 years as a fishing vessel, was commissioned by the Royal Navy for minesweeping duties during the Second World War. She sank in December 1944 due to "stress of weather" whilst under tow. Today she remains largely intact, sitting upright with just a slight list to starboard. Her stern is to the north and she is sanded up to the gunwhales. The surrounding sea bed is of silty gravel and coarse shell fragments. The marine biological interest lies in the fact that the communities present here are typical of many deep water wrecks found off the coast of West Sussex. The presence of Devonshire cup corals Caryophyllia smithii and jewel anemones Corynactis viridis is of special note.

Biological Description

The vertical sides of the hull are dominated by a turf of bryozoan and hydroid species, particularly of the hydroid Tubularia indivisa. The tentacular heads of this species are a favourite prey item for several organisms including sea slugs, and by the end of the summer all that may remain of the hydroid are its twig-like stems protruding 10-12 cm from the wreck's surface. There are also a few patches of Devonshire cup corals Caryophyllia smithii and a small group of jewel anemones Corynactis viridis near the bow. Both of these species are more common in the clearer water of the western English Channel, so their presence here is close to the eastern edge of their known distribution. Other attached fauna include bryozoan crusts, crissid bryozoans, occasional white anemones Actinothoe sphyrodeta, small growths of the sponge Dysidea fragilis. Plumose anemones Metridium senile and colonies of the soft coral Alcyonium digitatum are present on the deck section, together with occasional large spider crabs Maja squinado and edible crabs Cancer pagurus. Silt covers much of the horizontal surfaces. Offshore wrecks often have large fishes associated with them and this one is no exception. Bib Trisopterus luscus are common, as are poor cod Trisopterus minutus. Other species less commonly seen are conger Conger conger and goldsinny Ctenolabrus rupestris.

The surrounding sea bed is a mix of silty gravel (80%) and coarse shell gravel (20%). Present here are sandmason worms Lanice conchilega, mussels Mytilus edulis, burrowing anemones Cerianthus lloydii and the 'finger' bryozoan Alcyonidium diaphanum. An unusual record from 1994 was of a small colony of zoanthid anemones partially buried in the gravel, thought to be Epizoanthus couchii.

References: Irving, R. A. 1994. Report of the West Sussex Seasearch Project, 1992-1993: Chichester Harbour to Littlehampton Unpublished Report, Coldwaltham, West Sussex

Sussex SEASEARCH dive nos.: 94/121

Site Location

Diagrammatic representation of site: H.M.S. Northcoates