Western Rocks, Isles of Scilly
|Site of Special Scientific Interest|
|Area of Search||Cornwall|
|Area||62.7 hectares (0.627 km2; 0.242 sq mi)|
|Natural England website|
The Western Rocks are a group of uninhabited islands and rocks in the south–western part of the Isles of Scilly, United Kingdom, and are renowned for the numerous shipwrecks in the area and the nearby Bishop Rock lighthouse. In 1971, the rocks and islands were designated a Site of Special Scientific Interest for their breeding sea birds. Landing on the islands is both difficult and discouraged and there are few published records of visits by naturalists. 
The islands are largely managed as nature reserves by the Isles of Scilly Wildlife Trust, principally for breeding seabirds and grey seals (Halichoerus grypus). There are eleven species of breeding seabirds with the European Shag (Phalacrocorax aristotelis) and European Storm–petrel (Hydrobates pelagicus) of national importance. The other species are Kittiwake (Rissa tridactyla), Razorbill (Alca torda), Guillemot (Uria aalge), Cormorant (Phalacrocorax carbo), Fulmar (Fulmarus glacialis), Puffin (Fratercula arctica), Great Black–backed Gull (Larus marinus), Lesser Black–backed Gull (Larus fuscus) and Herring Gull (Larus argentatus).
The only breeding sites for European Storm–petrel in England are on the Isles of Scilly with eleven colonies and an estimated 1475 occupied sites (i.e. breeding pairs). Melledgan did have the third largest colony on Scilly with 140 occupied sites recorded during the Seabird 2000 survey declining to 69 occupied sites in a repeat survey in 2006. It was replaced by Roseveor in 2006 with 129 breeding pairs. Other Western Rock colonies are on Gorregan and Rosevean.
All of the Western Rocks are composed of Hercynian granite of late Carboniferous age with thin podzolic soils on the larger ones. They are located south-west of St Mary's, with Annet and St Agnes immediately to the north-east and the Bishop Rock to the west. The larger islands in this archipelago are, from north to south: Great Crebwethan, Rosevear, Rosevean, Daisy and Pednathise Head. Rosevear Ledge and the Gilstone Reef are just to the west of this group. Smaller islands within the Western Rocks are: Codnors Rocks, Crebwethan, Jolly Rock, Jacky's Rock, Silver Carn, Gorregan and Melledgan.
Individual islands and rocks
Some of the islands and rocks are listed below. Area is measured at MHWS (figures are provided by the Isles of Scilly Wildlife Trust):
A haul-out site for grey seal.
The Gilstone (Gilstone Reef or Gilstone Rock, for an image see here) is also known as Outer Gilstone Rock to distinguish it from a rock off Old Town Bay on St Mary's which is also called Gilstone. Gilstone has been the cause of many of the shipwrecks recorded in the Isles of Scilly, most notably the sinking of Admiral Sir Cloudesley Shovell's flagship HMS Association in the naval disaster of 1707 with the loss of over 1400 lives.
The smooth square fissured rocks of Gorregan (8 metres (26 ft) high) is a contrast to the other islands which are a ″disordered jumble″ of rocks. The only plants recorded are common scurvygrass (Cochlearia officinalis), rock sea–spurry (Spergularia rupicola) and orache (Atriplex sp). The breeding colony of European Storm–petrel had 49 occupied sites recorded during the Seabird 2000 survey and there is a large colony of Kittiwake, although in 1984 there was no breeding because of (possible) predation by Carrion Crow (Corvus corone) or Common Raven (Corvus corax). Other breeding birds are Razorbill and Guillemot. Grey seals use the island as a pupping site.
The island was surveyed for European Storm–petrel during the Seabird 2000 survey with none found.
A group of rocks to the south of Annet.
Melledgan was the site of the third largest colony of European Storm–petrel in England with 140 occupied sites recorded during the Seabird 2000 survey declining to 69 occupied sites in a repeat survey in 2006 and being replaced by Roseveor. Cormorant and Shag also breed on the island and it is a main pupping and haul–out site for grey seal. The seals' droppings enrich the shingle plant community. Plants recorded are tree mallow (Lavatera arborea), spear–leaved orache (Atriplex prostrata) and common scurvygrass.
Apart from the occasional plant Rosevean consists mainly of bare rocks and is important for its breeding birds and, as a haul–out site for grey seals. The island was surveyed for European Storm–petrel during the Seabird 2000 survey with 37 occupied sites recorded.
Rosevear is the largest of the Western Rocks with a relatively flat top to 5 metres (16 ft). In the 1840s and 1850s it was inhabited by workmen building the Bishop Rock lighthouse. Two of the four cottages built to house the workman can still be seen amongst the dense stands of tree mallow and it is said they grew some vegetables. During storms the sea can wash over the island and there is a shingle community of plants with tree mallow, sea curled dock (Rumex cripus littoreus) and Atriplex sp. The only other species recorded are sea beet (Beta vulgaris subsp. maritima), common scurvygrass, orache sp and rock sea spurry. A visit by Geoffrey Grigson in or around 1947 found a few Puffin, scores of Razorbill, Shags and Great Black–back Gull, and a heavy fall of migrants was seen on a visit by Rosemary Parslow in October 1990 with dozens of European Robin (Erithacus rubecula) and Goldcrest (Regulus regulus), and several Yellow–browed Warbler (Phylloscopus inornatus) all feeding amongst the vegetation. The island has replaced Melledgan as the site of the third largest colony of European Storm–petrel in England with 57 occupied sites recorded during the Seabird 2000 survey increasing to 129 occupied sites in the repeat survey in 2006. The colony of Shag on Rosevear and the rest of the Western Rocks is of national importance.
The Western Rocks in history
Unlike the rest of the islands there is no evidence of any human occupation on the Western Rocks, apart from the temporary worksite on Rosevear in the mid–nineteenth century.
Navigation, especially in cloudy weather, was often an informed guess based on assumed speed and direction. With a poor understanding of the sea current, in the western approaches, which pushed sailing ships further north than expected, and the problem of pre–1750 charts showing the rocks a further ten miles north than they actually are, it is not surprising that throughout history the Western Rocks have witnessed a great number of the shipwrecks recorded in the Isles of Scilly. Particularly the Gilstone Reef has been the cause of many maritime disasters, most notably the sinking of Admiral Sir Cloudesley Shovell's flagship HMS Association in the naval disaster of 1707 with the loss of over 1400 lives.
Seventy–seven years later, in 1784, a packet ship the Nancy hit the Gilstone. Some of the crew and passengers took to a small boat which was dashed on to Rosevear killing all those aboard. A total of 36 crew, 12 passengers, and 1 prisoner drowned including the infamous actress Ann Cargill. She was returning to England from India and her body was found clinging to a young child and they were buried on Rosevear along with other bodies found. She was later interred in the churchyard in Old Town on St Mary's.
In 1841 the captain of a paddle steamer the SS Thames mistook the lighthouse on St Agnes for the Longships, changed course to north and steamed onto the Cribewidden Rocks with the loss of 62 of the 66 passengers and crew. The second known heaviest loss of life occurred in 1875 when the German liner the SS Schiller hit the Retarrier Ledges with the loss of 335 lives. Her captain knew she was near the Bishop Light but didn't realise he was within the Western Rocks.
The various wrecks are popular diving sites for both commercial and amateur divers with searches made to identify and record the wrecks.
|Wikimedia Commons has media related to Western Rocks, Isles of Scilly.|
- "Western Rocks". Natural England. 5 December 1986. Retrieved 15 February 2012.
- Parslow, Rosemary (2007). The Isles of Scilly. London: HarperCollins. ISBN 978-0-00-220150-6.
- "Seabird Populations of Britain and Ireland: results of the Seabird 2000 census (1998-2002).". London: T and A.D. Poyser. Retrieved 15 November 2012.
- Ordnance Survey: Explorer map sheet 101 Isles of Scilly isbn= 978-0-319-23702-1
- Sneddon, P E; Randall R E (1994). Coastal vegetated shingle structures of Great Britain: Appendix 3. Shingle sites in England. Cambridge: JNCC. p. 104. ISBN 1873701187.
- Parslow, Rosemary (2008). "Field meeting reports: 2008 - Isles of Scilly". BSBI News (109): 62–6. Retrieved 20 July 2013.
- Thomas, Charles (1985). Exploration of a Drowned Landscape. London: B T Batsford Ltd.
- Reid, Neil (2007). Isles of Scilly Guidebook. Cormorant Design. ISBN 1904645038.
- A photograph of the Outer Gilstone Rock from www.shipwrecks.uk.com. Retrieved 21 February 2010.
- Larn, Richard; Larn, Bridget. Wreck & Rescue round the Cornish coast. Redruth: Tor Mark Press. p. 48. ISBN 978-0-85025-406-8.
- "Museum News". Scilly Up To Date. April 1999. Retrieved 2 November 2011.
- Stevens, Carmen. "Diving on Scilly". Retrieved 12 June 2012.