Celtic Sea

The Celtic Sea (Irish: An Mhuir Cheilteach; Welsh: Y Môr Celtaidd; Cornish: An Mor Keltek; Breton: Ar Mor Keltiek; French: La mer Celtique) is the area of the Atlantic Ocean off the south coast of Ireland bounded to the east by Saint George's Channel;[1] other limits include the Bristol Channel, the English Channel, and the Bay of Biscay, as well as adjacent portions of Wales, Cornwall, Devon, and Brittany. The southern and western boundaries are delimited by the continental shelf, which drops away sharply. The Isles of Scilly are an archipelago of small islands in the sea.

Celtic Sea
Celtic Sea - panoramio
Celtic Sea in July 2011
Celtic Sea and Bay of Biscay bathymetric map-en
Bathymetric map of the Celtic Sea, part of the Atlantic Ocean, and its surroundings
Coordinates50°N 8°W / 50°N 8°WCoordinates: 50°N 8°W / 50°N 8°W
Basin countriesIreland, England, Wales, France


The Celtic Sea receives its name from the Celtic heritage of the bounding lands to the north and east.[2] The name was first proposed by E. W. L. Holt at a 1921 meeting in Dublin of fisheries experts from Great Britain, France, and Ireland.[2] The northern portion of this sea was considered as part of Saint George's Channel and the southern portion as an undifferentiated part of the "Southwest Approaches" to Great Britain. The desire for a common name came to be felt because of the common marine biology, geology and hydrology of the area.[2] It was adopted in France before being common in the English-speaking countries;[2] in 1957 Édouard Le Danois wrote, "the name Celtic Sea is hardly known even to oceanographers."[3] It was adopted by marine biologists and oceanographers, and later by petroleum exploration firms.[4] It is named in a 1963 British atlas,[5] but a 1972 article states "what British maps call the Western Approaches, and what the oil industry calls the Celtic Sea [...] certainly the residents on the western coast [of Great Britain] don't refer to it as such."[6]


There are no land features to divide the Celtic Sea from the open Atlantic Ocean to the south and west. For these limits, Holt suggested the 200-fathom (370 m; 1,200 ft) marine contour and the island of Ushant off the tip of Brittany.

The definition approved by 1974 by the UK Hydrographer of the Navy for use in Admiralty Charts was "bounded roughly by lines joining Ushant, Land's End, Hartland Point, Lundy Island, St. Govan's Head and Rosslare, thence following the Irish coast south to Mizen Head and then along the 200-metre isobath to approximately the latitude of Ushant."[7]

The International Hydrographic Organization defines the limits of the Celtic Sea as follows:[8]

On the North. The Southern limit of the Irish Sea [a line joining St David's Head to Carnsore Point], the South coast of Ireland, thence from Mizen Head a line drawn to a position 51°0′N 11°30′W / 51.000°N 11.500°W.

On the West and South. A line from the position 51°0′N 11°30′W / 51.000°N 11.500°W South to 49°N, thence to latitude 46°30'N on the Western limit of the Bay of Biscay [a line joining Cape Ortegal to Penmarch Point], thence along that line to Penmarch Point.

On the East. The Western limit of the English Channel [a line joining Île Vierge to Land's End] and the Western limit of the Bristol Channel [a line joining Hartland Point to St. Govan's Head].


The seabed under the Celtic Sea is called the Celtic Shelf, part of the continental shelf of Europe. The northeast portion has a depth of between 90 and 100 m (300–330 ft), increasing towards Saint George's Channel. In the opposite direction, sand ridges pointing southwest have a similar height, separated by troughs approximately 50 m (160 ft) deeper. These ridges were formed by tidal effects when the sea level was lower. South of 50°N the topography is more irregular.[9]

Oil and gas exploration in the Celtic Sea has had limited commercial success. The Kinsale Head gas field supplied much of the Republic of Ireland in the 1980s and 1990s.

Ecology of the Celtic Sea

The Celtic Sea has a rich fishery with total annual catches of 1.8 million tonnes as of 2007.[10]

Four cetacean species occur frequently in the area: minke whale, bottlenose dolphin, short-beaked common dolphin and harbor porpoise.[11] Formerly, it held an abundance of marine mammals.[12][13]

See also


  1. ^ C.Michael Hogan. 2011. Celtic Sea. eds. P.saundry & C.Cleveland. Encyclopedia of Earth. National Council for Science and the /environment. Washington DC.
  2. ^ a b c d Haslam, D. W. (Hydrographer of the Royal Navy) (29 March 1976). "It's the Celtic Sea—official". The Times (59665). p. 15 (Letters to the Editor), col G.
  3. ^ Danois, Edouard Le (1957). Marine Life of Coastal Waters: Western Europe. Harrap. p. 12.
  4. ^ Cooper, L. H. N. (2 February 1972). "In Celtic waters". The Times (58391). p. 20; col G (Letters to the Editor).
  5. ^ The Atlas of Great Britain and Northern Ireland. Clarendon Press. 1963. pp. 20–21.; cited in
    Shergold, Vernon G. (27 January 1972). "Celtic Sea: a good name". The Times (58386). p. 20 (Letters to the Editor); col G.
  6. ^ Vielvoye, Roger (24 January 1972). "Industry in the regions Striking oil in Wales and West Country". The Times (58383). p. 19; col A.
  7. ^ "Celtic Sea". Parliamentary Debates (Hansard). 883. House of Commons. 16 December 1974. col. 317W.
  8. ^ "Limits of Oceans and Seas, 3rd edition + corrections" (PDF). International Hydrographic Organization. 1971. p. 42 [corrections to page 13]. Retrieved 6 February 2010.
  9. ^ Hardisty, Jack (1990). The British Seas: an introduction to the oceanography and resources of the north-west European continental shelf. Taylor & Francis. pp. 20–21. ISBN 0-415-03586-4.
  10. ^ European Union. "Celtic Seas". European Atlas of the Seas. Archived from the original on 24 July 2015. Retrieved 13 March 2015.
  11. ^ Hammond, P.S.; Northridge, S.P.; Thompson, D.; Gordon, J.C.D. (2008). "1 Background information on marine mammals for Strategic Environmental Assessment 8" (PDF). Sea Mammal Research Unit. Retrieved 13 March 2015.
  12. ^ Van Deinse, A.B.; Junge, G. C. A. (1936). "Recent and older finds of the California grey whale in the Atlantic". Temminckia. 2: 161–88.
  13. ^ Fraser, F.C. (1936). "Report on cetacea stranded on the British Coasts from 1927 to 1932". British Museum (Natural History) No. 11, London, UK.

External links

Bay of Biscay

The Bay of Biscay (; French: Golfe de Gascogne, Spanish: Golfo de Vizcaya, Occitan: Golf de Gasconha, Breton: Pleg-mor Gwaskogn, Basque: Bizkaiko Golkoa) is a gulf of the northeast Atlantic Ocean located south of the Celtic Sea. It lies along the western coast of France from Point Penmarc'h to the Spanish border, and the northern coast of Spain west to Cape Ortegal.

The south area of the Bay of Biscay washes over the northern coast of Spain and is known as the Cantabrian Sea.

The average depth is 1,744 metres (5,722 ft) and the greatest depth is 4,735 metres (15,535 ft).

European countries by percentage of urban population

The map data is for year 2014 from the World Bank. Numbers are in percentage.

Fastnet Rock

Fastnet Rock, or simply Fastnet (possibly from Old Norse Hvasstein-ey, meaning 'sharp-tooth isle'; called Carraig Aonair, meaning "lonely rock", in Irish) is a small islet in the Atlantic Ocean and the most southerly point of Ireland. It lies 6.5 kilometres (4.0 mi) southwest of Cape Clear Island and 13 kilometres (8.1 mi) from County Cork on the Irish mainland. Fastnet is known as "Ireland's Teardrop", because it was the last part of Ireland that 19th-century Irish emigrants saw as they sailed to North America.Fastnet Rock is a small clay-slate islet with quartz veins. It rises to about 30 metres (98 ft) above low water mark and is separated from the much smaller southern Little Fastnet by a 10-metre (33 ft) wide channel. Fastnet also gives its name to the sea area used by the Shipping Forecasts on BBC Radio 4. The current lighthouse is the second to be built on the rock and is the highest in Ireland.

Fastnet Rock is used as the midpoint of one of the world's classic offshore yachting races, the Fastnet Race, a 1,126 kilometres (700 mi) round trip from Cowes on the Isle of Wight, round the rock and back to Plymouth. It is also sometimes used as a mark for yacht races from local sailing centres such as Schull, Baltimore, and Crookhaven.

German submarine U-1021

German submarine U-1021 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine during World War II.

laid down on 6 May 1943 at the Blohm & Voss yard in Hamburg, the submarine was launched on 13 April 1944, and commissioned on 25 May 1944, under the command of Oberleutnant zur See William Holpert.

German submarine U-1200

German submarine U-1200 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine which saw service during the Second World War.

German submarine U-1276

German submarine U-1276 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine, built for service during World War II. She was laid down at Bremer Vulkan of Bremen-Vegesack on 13 July 1943. She was commissioned 6 April 1944 with Oberleutnant zur See Karl Heinz Wendt in command. U-1276 was equipped with a submarine snorkel (underwater-breathing apparatus) when she sailed on her last cruise.

German submarine U-772

German submarine U-772 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.

The U-boat was laid down on 21 September 1942 at the Kriegsmarinewerft Wilhelmshaven (KMW), launched on 31 October 1943, and commissioned on 23 December 1943, commanded by Kapitänleutnant Ewald Rademacher.

List of lighthouses in Ireland

This is a list of lighthouses in Ireland. The Commissioners of Irish Lights are responsible for the majority of marine navigation aids around the island though a small number are maintained by local harbour authorities. The main list identifies those lighthouses in a clockwise direction starting with Crookhaven lighthouse, County Cork.

List of sovereign states in Europe by GDP (nominal)

Map of European countries by Nominal GDP in billions USD.

Data produced by the International Monetary Fund for the year 2018.

List of sovereign states in Europe by GNI (PPP) per capita

This is map and list of European countries by Gross national income (PPP) per capita for year 2017 from World Bank. Countries in green have more than $32,000, yellow $18,000-$32,000 and red below $18,000 GDP (PPP) per capita

MV Kowloon Bridge

MV Kowloon Bridge was a Bridge-class ore-bulk-oil combination carrier built by Swan Hunter in 1973. She sank off the coast of the Republic of Ireland in December 1986.

Munster Blackwater

The Blackwater or Munster Blackwater (Irish: An Abha Mhór, The Big River) is a river which flows through counties Kerry, Cork, and Waterford in Ireland. It rises in the Mullaghareirk Mountains in County Kerry and then flows in an easterly direction through County Cork, through Mallow and Fermoy. It then enters County Waterford where it flows through Lismore, before abruptly turning south at Cappoquin, and finally draining into the Celtic Sea at Youghal Harbour. In total, the Blackwater is 169 km (105 mi) long.

The total catchment area of the River Blackwater is 3,324 km2.

The long term average flow rate of the River Blackwater is 89.1 Cubic Metres per second (m3/s)The Blackwater is notable for being one of the best salmon fishing rivers in the country. Like many Irish and British rivers, salmon stocks declined in recent years, but the Irish Government banned commercial netting of salmon off the coast of Ireland in November 2006.

River Gannel

The River Gannel (Cornish: Dowr Gwyles, meaning lovage river) rises in the village of Indian Queens in mid Cornwall, England, United Kingdom. It flows north under Trevemper Bridge and becomes a tidal estuary, the Gannel (Cornish: An Ganel, meaning the Channel), that divides the town of Newquay from the village of Crantock and joins the Celtic Sea.

The estuary contains a historic boatyard and is an important location for migratory birds.

The river is known for a legend called the Gannel Crake, an unusual noise which might be heard "crying out". During the 19th century it was described as being like "a thousand voices pent up in misery, with one long wail dying away in the distance". It is traditionally referred to by the superstitious natives as the cry of a troubled spirit that ever haunts the scene.

River Mahon

The River Mahon (Irish: an Mhachan) flows from the Comeragh Mountains in County Waterford, Ireland.

Falling down the 80-metre Mahon Falls and proceeding past the "Fairy Bush",(fairy bush is now chopped down) the river then passes through the village of Mahon Bridge and on past Flahavan's Mill and under the 8-arched rail bridge in Kilmacthomas. In former times, the river powered five different mills, one at Mahon Bridge, three at Kilmacthomas and one at Ballylaneen. The river is joined by the Ách Mór tributary river at Ballylaneen and ends its journey three miles further downstream at Bunmahon on Ireland's south coast. It drains into the region of the Atlantic Ocean known as the Celtic Sea.

The river is popular with whitewater kayakers. There has been no known source-to-sea descent to date but the river has been paddled from Mahon Bridge to the sea at Bonmahon by an international team of B1 and B2 kayakers in August 2012.

On 21 October 2005, Michael Reynolds, a kayaker from Tramore, County Waterford, performed the only known descent in a kayak of the vertical 55 foot drop at the top of Mahon falls.

River Nore

The River Nore (Irish: An Fheoir) is a 140-kilometre (87 mi) long river located in south-east of Ireland. Along with the River Suir and River Barrow, it is one of the constituent rivers of the group known as the Three Sisters. The river drains approximately 977 square miles (2,530 km2) of Leinster. The long term average flow rate of the River Nore is 42.9 cubic metres per second (m3/s) The river rises in the Devil's Bit Mountain, County Tipperary. Flowing generally southeast, and then south, before emptying into the Celtic Sea at Waterford Harbour, Waterford.

Parts of the river are listed as Special Areas of Conservation.

Rivers of Ireland

Shown here are all the major rivers and tributaries of Ireland with their lengths (in kilometres and miles). Starting with the Northern Ireland rivers, and going in a clockwise direction, the rivers (and tributaries) are listed in regard to their entry into the different seas: the Irish Sea, the Celtic Sea and the Atlantic Ocean. Also shown are two tables. Table 1 shows the longest rivers in Ireland with their lengths (in kilometres and miles), the counties they flow through, and their catchment areas (in square kilometres). Table 2 shows the largest rivers in Ireland (by mean flow) in cubic metres per second.

The longest river in Ireland is the River Shannon, at 360.5 kilometres (224.0 mi). The river develops into three lakes along its course, Lough Allen, Lough Ree and Lough Derg. Of these, Lough Derg is the largest. The Shannon enters the Atlantic Ocean at the Shannon Estuary. Other major rivers include the River Liffey, River Lee, River Swilly, River Foyle, River Lagan, River Erne, River Blackwater, River Nore, River Suir, River Barrow (The Three Sisters), River Bann, River Slaney, River Boyne, River Moy and River Corrib.

SM U-58

SM U-58 was one of the 329 submarines serving in the Imperial German Navy in World War I.

U-58 was engaged in the naval warfare and took part in the First Battle of the Atlantic.

St George's Channel

St George's Channel (Welsh: Sianel San Siôr, Irish: Muir Bhreatan) is a sea channel connecting the Irish Sea to the north and the Celtic Sea to the southwest.Historically, the name "St George's Channel" was used interchangeably with "Irish Sea" or "Irish Channel" to encompass all the waters between Ireland to the west and Great Britain to the east. Some geographers restricted it to the portion separating Wales from Leinster, sometimes extending south to the waters between the West Country of England and East Munster; the latter have since the 1970s come to be called the Celtic Sea. In Ireland "St George's Channel" is now usually taken to refer only to the narrowest part of the channel, between Carnsore Point in Wexford and St David's Head in Pembrokeshire. However, it remains common in Ireland to talk about a cross-channel trip, cross-channel soccer, etc., where "cross-channel" means "to/from Great Britain".The current (third, 1953) edition of the International Hydrographic Organization's publication Limits of Oceans and Seas defines the southern limit of "Irish Sea and St. George's Channel" as "A line joining St. David's Head (51°54′N 5°19′W) to Carnsore Point (52°10′N 6°22′W)"; it does not define the two waterbodies separately. The 2002 draft fourth edition omits the "and St. George's Channel" part of the label.A 2004 letter from the St.George's Channel Shipping Company to Seascapes, an RTÉ Radio programme, said that St George's Channel bordered the Irish coast between Howth Head and Kilmore Quay, and criticised contributors to the programme who had used "Irish Sea" for these waters.The name "St George's Channel" is recorded in 1578 in Martin Frobisher's record of his second voyage. It is said to derive from a legend that Saint George had voyaged to Roman Britain from the Byzantine Empire, approaching Britain via the channel that bears his name. The name was popularised by English settlers in Ireland after the Plantations.

Wild Atlantic Way

The Wild Atlantic Way (Irish: Slí an Atlantaigh Fhiáin) is a tourism trail on the west coast, and on parts of the north and south coasts, of Ireland. The 2,500 km (1,553 mile) driving route passes through nine counties and three provinces, stretching from County Donegal's Inishowen Peninsula in Ulster to Kinsale, County Cork, in Munster, on the Celtic Sea coast.The route is broken down into 5 sections.

County Donegal

County Donegal to County Mayo

County Mayo to County Clare

County Clare to County Kerry

County Kerry to County CorkAlong the route there are 157 discovery points, 1,000 attractions and more than 2,500 activities. The route was officially launched in 2014 by Minister of State for Tourism and Sport, Michael Ring, T.D..

Arctic Ocean
Atlantic Ocean
Indian Ocean
Pacific Ocean
Southern Ocean
Endorheic basins
Marginal seas of the Atlantic Ocean

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.