Irish Sea
Encyclopedia
The Irish Sea separates the islands of Ireland
and Great Britain
. It is connected to the Celtic Sea
in the south by St George's Channel
, and to the Atlantic Ocean
in the north by the North Channel. Anglesey
is the largest island within the Irish Sea, followed by the Isle of Man
. The sea is occasionally, but rarely, referred to as the Manx Sea.
The sea is of significant economic importance to regional trade
, shipping
and transport
, fishing
, and power generation in the form of wind power
and nuclear plants. Annual traffic between Great Britain and Ireland amounts to over 12 million passengers and 17 million tonne
s of traded goods.
defines the limits of the Irish Sea (with St George's Channel) as follows:
connection to mainland Europe. Thus the vast majority of heavy goods trade is done by sea
. Northern Ireland
port
s handle 10 million tonnes of goods trade with Great Britain annually, while ports in the Republic of Ireland
handle 7.6 million tonnes, representing 50% and 40% respectively of total trade by weight
.
The Port of Liverpool
handles 32 million tonnes of cargo
and 734 thousand passengers a year. Holyhead
port handles most of the passenger traffic from Dublin
and Dún Laoghaire
ports, as well as 3.3 million tonnes of freight.
Ports in the Republic handle 3,600,000 travellers crossing the sea each year, amounting to 92% of all Irish Sea travel. This has been steadily dropping for a number of years (20% since 1999), probably as a result of low cost airlines.
Ferry
connections from Great Britain to Ireland across the Irish Sea include the routes from Swansea
to Cork
, Fishguard
and Pembroke to Rosslare
, Holyhead to Dún Laoghaire, Holyhead to Dublin, Stranraer
to Belfast
and Larne
, and Cairnryan
to Larne. There is also a connection between Liverpool
and Belfast via the Isle of Man
or direct from Birkenhead
. The world's largest car ferry
, Ulysses
, is operated by Irish Ferries on the Dublin Port–Holyhead route; Stena Line
also operates between Britain and Ireland. The Port of Barrow-in-Furness
, despite being one of Britain's largest shipbuilding
centres and being home to the United Kingdom
's only submarine
-building complex, is only a minor port.
"Irish Sea" is also the name of one of the BBC
's Shipping Forecast
areas defined by the coordinates:
54°50′N 05°05′W
54°45′N 05°45′W
52°30′N 06°15′W
52°00′N 05°05′W
There have been various tentative proposals for an Irish Sea Tunnel
.
During World War I
the Irish Sea became known as "U-boat
Alley", because the U-boats moved their emphasis from the Atlantic
to the Irish Sea after the United States
entered the war in 1917.
lake
. As the ice
retreated 10,000 years ago the lake reconnected to the sea, becoming brackish and then fully saline
once again.
resource of the Irish Sea lies in its estuaries: particularly the Dee Estuary
, the Mersey Estuary, the Ribble Estuary
, Morecambe Bay
, the Solway Firth
, Loch Ryan
, the Firth of Clyde
, Belfast Lough
, Strangford Lough
, Carlingford Lough
, Dundalk Bay
, Dublin Bay
and Wexford Harbour
. However, a lot of wildlife also depends on the cliff
s, salt marsh
es and sand dunes of the adjoining shore
s, the seabed
and the open sea itself.
The information on the invertebrate
s of the seabed of the Irish Sea is rather patchy because it is difficult to survey such a large area, where underwater visibility is often poor and information often depends upon looking at material brought up from the seabed in mechanical grabs. However, the groupings of animal
s present depend to a large extent on whether the seabed is composed of rock
, boulder
s, gravel
, sand
, mud
or even peat
. In the soft sediment
s seven types of community have been provisionally identified, variously dominated by brittle-stars, sea urchin
s, worm
s, mussel
s, tellins
, furrow-shell
s, and tower-shells.
Parts of the bed of the Irish Sea are very rich in wildlife. The seabed southwest of the Isle of Man is particularly noted for its rarities and diversity, as are the horse mussel
beds of Strangford Lough. Scallop
s and queen scallop
s are found in more gravelly areas. In the estuaries, where the bed is more sandy or muddy, the number of species is smaller but the size of their populations is larger. Brown shrimp, cockle
s and edible mussels support local fisheries in Morecambe Bay and the Dee Estuary and the estuaries are also important as nurseries for flatfish
, herring
and sea bass
. Muddy seabeds in deeper waters are home to populations of the Dublin Bay prawn, also known as "scampi".
The open sea is a complex habitat in its own right. It exists in three spatial dimensions and also varies over time and tide. For example, where freshwater flows into the Irish Sea in river estuaries its influence can extend far offshore as the freshwater is lighter and "floats" on top of the much larger body of saltwater until wind
and temperature
changes mix it in. Similarly, warmer water is less dense and seawater warmed in the inter-tidal zone may "float" on the colder offshore water. The amount of light penetrating the seawater also varies with depth and turbidity. This leads to differing populations of plankton
in different parts of the sea and varying communities of animals that feed on these populations. However, increasing seasonal storm
iness leads to greater mixing of water and tends to break down these divisions, which are more apparent when the weather is calm for long periods.
Plankton includes bacteria
, plant
s (phytoplankton
) and animals (zooplankton
) that drift in the sea. Most are microscopic, but some, such as the various species of jellyfish
and sea gooseberry
, can be much bigger.
Diatom
s and dinoflagellate
s dominate the phytoplankton. Although they are microscopic plants, diatoms have hard shells and dinoflagellates have little tail
s that propel them through the water. Phytoplankton populations in the Irish Sea have a spring "bloom" every April and May, when the seawater is generally at its greenest.
Crustacean
s, especially copepod
s, dominate the zooplankton. However, many animals of the seabed, the open sea and the seashore spend their juvenile stages as part of the zooplankton. The whole plankton "soup" is vitally important, directly or indirectly, as a food source for most species in the Irish Sea, even the largest. The enormous basking shark
, for example, lives entirely on plankton and the leatherback turtle's main food is jellyfish.
A colossal diversity of invertebrate
species
live in the Irish Sea and its surrounding coastline, ranging from flower
-like fan-worms to predatory swimming crabs
to large chameleon
-like cuttlefish
.
Some of the most significant for other wildlife are the reef-building species like the inshore horse mussel of Strangford Lough and the inter-tidal honeycomb worm of Morecambe Bay, Cumbria
and Lancashire
. These build up large structures over many years and, in turn, provide surfaces, nooks and crannies where other marine animals and plants may become established and live out some or all of their lives.
There are quite regular records of live and stranded leatherback turtle in and around the Irish Sea. This species travels north to the waters off the British Isles
every year following the swarms of jellyfish that form its prey. Loggerhead turtle, Ridley sea turtle
and green turtle are found very occasionally in the Irish Sea but are generally unwell or dead when discovered. They have strayed or been swept out of their natural range further south into colder waters.
The estuaries of the Irish Sea are of international importance for bird
s. They are vital feeding grounds on migration
flyways for shorebirds travelling between the Arctic
and Africa
. Others depend on the milder climate as a refuge when continental Europe is in the grip of winter.
Twenty-one species of seabird
are reported as regularly nesting on beach
es or cliffs around the Irish Sea. Huge populations of the sea duck, common scoter
, spend winters feeding in shallow waters off eastern Ireland, Lancashire and North Wales
.
Whale
s, dolphin
s and porpoise
s all frequent the Irish Sea, but knowledge of how many there may be and where they go is somewhat sketchy. About a dozen species have been recorded since 1980, but only three are seen fairly often. These are the harbour porpoise
, bottlenose dolphin
and common dolphin
. The more rarely seen species are minke whale
, fin whale
, sei whale
, sperm whale
, northern bottlenose whale, long-finned pilot whale
, orca
, white-beaked dolphin
, striped dolphin
and Risso's dolphin
.
The common or harbour seal and the grey seal
are both resident in the Irish Sea. Common seal
s breed in Strangford Lough, grey seals in southwest Wales and, in small numbers, on the Isle of Man. Grey seals haul out, but do not breed, off Hilbre
and Walney
islands, Merseyside
, the Wirral
, Barrow-in-Furness Borough, and Cumbria.
as the most radioactively contaminated
sea in the world with some "eight million litre
s of nuclear waste" discharged into it each day from Sellafield
reprocessing plants, contaminating seawater, sediments and marine life.
Low-level radioactive
waste has been discharged into the Irish Sea as part of operations at Sellafield since 1952. The rate of discharge began to accelerate in the mid- to late 1960s, reaching a peak in the 1970s and generally declining significantly since then. As an example of this profile, discharges of plutonium
(specifically 241Pu) peaked in 1973 at 2,755TBq
falling to 8.1 TBq by 2004. Improvements in the treatment of waste in 1985 and 1994 resulted in further reductions in radioactive waste discharge although the subsequent processing of a backlog resulted in increased discharges of certain types of radioactive waste. Discharges of technetium
in particular rose from 6.1 TBq in 1993 to a peak of 192TBq in 1995 before dropping back to 14TBq in 2004. In total 22PBq of 241Pu was discharged over the period 1952 to 1998. Current rates of discharge for many radionuclides are at least 100 times lower than they were in the 1970s.
Analysis of the distribution of radioactive contamination after discharge reveals that mean sea currents result in much of the more soluble elements such as caesium
being flushed out of the Irish Sea through the North Channel about a year after discharge. Measurements of technetium concentrations post-1994 has produced estimated transit times to the North Channel of around six months with peak concentrations off the northeast Irish coast occurring 18–24 months after peak discharge. Less soluble elements such as plutonium are subject to much slower redistribution. Whilst concentrations have declined in line with the reduction in discharges they are markedly higher in the eastern Irish Sea compared to the western areas. The dispersal of these elements is closely associated with sediment activity, with mud
dy deposits on the seabed acting as sinks, soaking up an estimated 200kg of plutonium
. The highest concentration is found in the eastern Irish Sea in sediment banks lying parallel to the Cumbrian coast. This area acts as a significant source of wider contamination as radionuclides are dissolved once again. Studies have revealed that 80% of current sea water contamination by caesium is sourced from sediment banks, whilst plutonium levels in the western sediment banks between the Isle of Man and the Irish coast are being maintained by contamination redistributed from the eastern sediment banks.
The consumption of seafood
harvested from the Irish Sea is the main pathway for exposure of human
s to radioactivity. The environmental monitoring report for the period 2003 to 2005 published by the Radiological Protection Institute of Ireland
(RPII) reported that in 2005 average quantities of radioactive contamination found in seafood ranged from less than 1Bq/kg for fish to under 44Bq/kg for mussels. Doses of man-made radioactivity received by the heaviest consumers of seafood in Ireland in 2005 was 1.10µSv
. This compares with a corresponding dosage of radioactivity naturally occurring in the seafood consumed by this group of 148µSv and a total average dosage in Ireland
from all sources of 3620µSv. In terms of risk to this group, heavy consumption of seafood generates a 1 in 18 million chance of causing cancer
. The general risk of contracting cancer in Ireland is 1 in 522. In the UK, the heaviest seafood consumers in Cumbria received a radioactive dosage attributable to Sellafield discharges of 0.22mSv (220µSv) in 2005. This compares to average annual dose of naturally sourced radiation received in the UK of 2.23mSv (2230µSv).
Also see Beaufort's Dyke
.
and 176 million barrels (28,000,000 m³) of petroleum
estimated by the field operators as initially recoverable hydrocarbon
reserves from eight producing fields (DTI, 2001), the East Irish Sea Basin is at a mature exploration phase. Early Namurian
basinal mudstone
s are the source rocks for these hydrocarbons. Production from all fields is from fault-bounded traps of the Lower Triassic
formation, principally the aeolian Sherwood Sandstone reservoir, top-sealed by younger Triassic continental mudstones and evaporite
s. Future mineral exploration
will initially concentrate on extending this play, but there remains largely untested potential also for gas and oil within widespread Carboniferous
fluvial
sandstone
reservoirs. This play requires intraformational mudstone seal units to be present, as there is no top-seal for reservoirs subcropping the regional base Permian
unconformity
in the east of the basin, and Carboniferous strata
crop out at the sea bed in the west.
basin contains up to 7 km³ of Permian and Triassic syn-rift sediments in an asymmetrical graben
that is bounded to the north
and south
by Lower Paleozoic
massif
s. Only two exploration wells have been drilled so far, and there remain numerous undrilled targets in tilted fault block plays. As in the East Irish Sea Basin, the principal target reservoir is the Lower Triassic, Sherwood Sandstone, top-sealed by younger Triassic mudstones and evaporites. Wells in the Irish Sector to the west have demonstrated that pre-rift, Westphalian
coal measures are excellent hydrocarbon source rocks, and are at peak maturity for gas generation (Maddox et al., 1995). Seismic profiles
clearly image these strata continuing beneath a basal Permian unconformity into at least the western part of the Caernarfon Bay Basin. The timing of gas generation presents the greatest exploration risk. Maximum burial of, and primary gas migration from, the source rocks could have terminated as early as the Jurassic
, whereas many of the tilted fault blocks were reactivated or created during Paleogene
inversion of the basin. However, it is also possible that a secondary gas charge occurred during regional heating associated with intrusion of Paleogene dykes, such as those that crop out nearby on the coastline of north Wales. (Floodpage et al., 1999) have invoked this second phase of Paleogene hydrocarbon generation as an important factor in the charging of the East Irish Sea Basin's oil and gas fields. It is not clear as yet whether aeromagnetic anomalies in the southeast of Caernarfon Bay are imaging a continuation of the dyke swarm into this area too, or whether they are instead associated with deeply buried Permian syn-rift volcanics. Alternatively, the fault block traps could have been recharged by exsolution of methane
from formation brine
s as a direct result of the Tertiary
uplift (cf. Doré and Jensen, 1996).
Basin forms a continuation into British waters of Ireland's North Celtic Sea Basin, which has two producing gas fields. The basin comprises a south-easterly deepening half-graben near the Welsh coastline, although its internal structure becomes increasingly complex towards the southwest. Permian to Triassic, syn-rift sediments within the basin are less than 3 km thick and are overlain by up to 4 km of Jurassic strata, and locally also by up to 2 km of Paleogene fluvio-deltaic sediments. The basin has a proven petroleum system, with potentially producible gas reserves at the Dragon discovery near the UK/ROI median line, and oil shows in a further three wells. The Cardigan Bay Basin contains multiple reservoir targets, which include the Lower Triassic (Sherwood Sandstone), Middle Jurassic
shallow marine sandstones and limestone (Great Oolite
), and Upper Jurassic fluvial sandstone, the reservoir for the Dragon discovery. The most likely hydrocarbon source rocks are Early Jurassic
marine mudstones. These are fully mature for oil generation in the west of the British sector, and are mature for gas generation nearby in the Irish sector. Gas-prone, Westphalian pre-rift coal measures may also be present at depth locally. The Cardigan Bay Basin was subjected to two Tertiary phases of compressive uplift, whereas maximum burial that terminated primary hydrocarbon generation was probably around the end of the Cretaceous
, or earlier if Cretaceous strata, now missing, were never deposited in the basin. Despite the Tertiary structuration, the Dragon discovery has proved that potentially commercial volumes of hydrocarbons were retained at least locally in Cardigan Bay. In addition to undrilled structural traps, the basin contains untested potential for stratigraphic entrapment of hydrocarbons near synsedimentary faults, especially in the Middle Jurassic section.
Oil is produced from the Lennox and Douglas fields. It is then treated at the Douglas Complex and piped 17 kilometres to an oil storage barge ready for export by tankers. Gas is produced from the Hamilton, Hamilton North and Hamilton East reservoirs. After initial processing at the Douglas Complex
the gas is piped by subsea pipeline to the Point of Ayr
gas terminal for further processing. The gas is then sent by onshore pipeline to PowerGen's combined cycle gas turbine power station
at Connah's Quay
. PowerGen is the sole purchaser of gas from the Liverpool Bay development.
The Liverpool Bay development comprises four offshore platforms. Offshore storage and loading facilities. The onshore gas processing terminal at Point of Ayr.
Production first started at each filed as follows: Hamilton North in 1995, Hamilton in 1996, Douglas in 1996, Lennox (oil only) in 1996 and Hamilton East 2001. The first contract gas sales were in 1996.
Liverpool Bay has been historically contaminated by discharges of sewage sludge, compromising water quality for this part of the Irish Sea.
, Unionist MP for North Belfast, called for the building of such a tunnel. A tunnel project has been discussed several times in the Irish parliament
. The idea for such a 34 km (21 mi) long rail
bridge
or tunnel
, continues to be mooted.
Several potential Irish Sea tunnel projects have been proposed, most recently the "Tusker Tunnel
" between the ports of Rosslare and Fishguard proposed by The Institute of Engineers of Ireland in 2004. A different proposed route between Dublin and Holyhead was proposed in 1997 by the British engineering firm Symonds. Either tunnel, at 80 kilometres (49.7 mi), would be by far the longest in the world, and would cost an estimated €20 billion.
An offshore wind farm was developed on the Arklow
Bank, Arklow Bank Wind Park
, about 10 km off the coast of County Wicklow
in the south Irish Sea. The site currently has seven GE 3.6 MW turbine
s, each with 104 m diameter rotor
s, the world's first commercial application of offshore wind turbines over three megawatts in size. The operating company, Airtricity
, has indefinite plans for nearly 100 further turbines on the site.
Further wind turbine sites include:
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
and Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
. It is connected to the Celtic Sea
Celtic Sea
The Celtic Sea is the area of the Atlantic Ocean off the south coast of Ireland bounded to the east by Saint George's Channel; 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...
in the south by St George's Channel
St George's Channel
St George's Channel is a sea channel connecting the Irish Sea to the north and the Celtic Sea to the southwest.Historically, the name "St Georges 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...
, and to the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
in the north by the North Channel. Anglesey
Anglesey
Anglesey , also known by its Welsh name Ynys Môn , is an island and, as Isle of Anglesey, a county off the north west coast of Wales...
is the largest island within the Irish Sea, followed by the Isle of Man
Isle of Man
The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is...
. The sea is occasionally, but rarely, referred to as the Manx Sea.
The sea is of significant economic importance to regional trade
Trade
Trade is the transfer of ownership of goods and services from one person or entity to another. Trade is sometimes loosely called commerce or financial transaction or barter. A network that allows trade is called a market. The original form of trade was barter, the direct exchange of goods and...
, shipping
Shipping
Shipping has multiple meanings. It can be a physical process of transporting commodities and merchandise goods and cargo, by land, air, and sea. It also can describe the movement of objects by ship.Land or "ground" shipping can be by train or by truck...
and transport
Transport
Transport or transportation is the movement of people, cattle, animals and goods from one location to another. Modes of transport include air, rail, road, water, cable, pipeline, and space. The field can be divided into infrastructure, vehicles, and operations...
, fishing
Fishing
Fishing is the activity of trying to catch wild fish. Fish are normally caught in the wild. Techniques for catching fish include hand gathering, spearing, netting, angling and trapping....
, and power generation in the form of wind power
Wind power
Wind power is the conversion of wind energy into a useful form of energy, such as using wind turbines to make electricity, windmills for mechanical power, windpumps for water pumping or drainage, or sails to propel ships....
and nuclear plants. Annual traffic between Great Britain and Ireland amounts to over 12 million passengers and 17 million tonne
Tonne
The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...
s of traded goods.
Extent
The International Hydrographic OrganizationInternational Hydrographic Organization
The International Hydrographic Organization is the inter-governmental organisation representing the hydrographic community. It enjoys observer status at the UN and is the recognised competent authority on hydrographic surveying and nautical charting...
defines the limits of the Irish Sea (with St George's Channel) as follows:
On the North. The Southern limit of the Scottish Seas [or Inner Seas off the West Coast of ScotlandInner Seas off the West Coast of ScotlandThe Inner Seas off the West Coast of Scotland is a marine area designated by the International Hydrographic Organization . It consists of a number of waterbodies between the Scottish mainland, the Outer Hebrides islands, and the coast of Northern Ireland....
, defined as "a line joining the South extreme of the Mull of GallowayMull of GallowayThe Mull of Galloway is the southernmost point of Scotland. It is situated in Wigtownshire, Dumfries and Galloway.A lighthouse is positioned at the point . Built in 1830 by engineer Robert Stevenson, the white-painted round tower is high...
(54°38'N) in ScotlandScotlandScotland is a country that is part of the United Kingdom. Occupying the northern third of the island of Great Britain, it shares a border with England to the south and is bounded by the North Sea to the east, the Atlantic Ocean to the north and west, and the North Channel and Irish Sea to the...
and Ballyquintin Point (54°20'N) in IrelandIrelandIreland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
"].
On the South. A line joining St. David's Head (51°54′N 5°19′W) to Carnsore Point
Carnsore PointCarnsore Point is a headland in the very South East corner of County Wexford, Ireland. This headland is Ireland's southern limit point of the Irish Sea....
(52°10′N 6°22′W).
Shipping
Unlike Great Britain, Ireland has no tunnel or bridgeBridge
A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...
connection to mainland Europe. Thus the vast majority of heavy goods trade is done by sea
Sea
A sea generally refers to a large body of salt water, but the term is used in other contexts as well. Most commonly, it means a large expanse of saline water connected with an ocean, and is commonly used as a synonym for ocean...
. Northern Ireland
Northern Ireland
Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west...
port
Port
A port is a location on a coast or shore containing one or more harbors where ships can dock and transfer people or cargo to or from land....
s handle 10 million tonnes of goods trade with Great Britain annually, while ports in the Republic of Ireland
Republic of Ireland
Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,...
handle 7.6 million tonnes, representing 50% and 40% respectively of total trade by weight
Weight
In science and engineering, the weight of an object is the force on the object due to gravity. Its magnitude , often denoted by an italic letter W, is the product of the mass m of the object and the magnitude of the local gravitational acceleration g; thus:...
.
The Port of Liverpool
Port of Liverpool
The Port of Liverpool is the name for the enclosed 7.5 mile dock system that runs from Brunswick Dock in Liverpool to Seaforth Dock, Seaforth, on the east side of the River Mersey and the Birkenhead Docks between Birkenhead and Wallasey on the west side of the river...
handles 32 million tonnes of cargo
Cargo
Cargo is goods or produce transported, generally for commercial gain, by ship, aircraft, train, van or truck. In modern times, containers are used in most intermodal long-haul cargo transport.-Marine:...
and 734 thousand passengers a year. Holyhead
Holyhead
Holyhead is the largest town in the county of Anglesey in the North Wales. It is also a major port adjacent to the Irish Sea serving Ireland....
port handles most of the passenger traffic from Dublin
Dublin Port
Dublin Port is Ireland's biggest sea port. It has both historical and contemporary economic importance. Approximatively two-thirds of the Republic of Ireland's port traffic goes via Dublin Port...
and Dún Laoghaire
Dún Laoghaire
Dún Laoghaire or Dún Laoire , sometimes anglicised as "Dunleary" , is a suburban seaside town in County Dublin, Ireland, about twelve kilometres south of Dublin city centre. It is the county town of Dun Laoghaire-Rathdown County and a major port of entry from Great Britain...
ports, as well as 3.3 million tonnes of freight.
Ports in the Republic handle 3,600,000 travellers crossing the sea each year, amounting to 92% of all Irish Sea travel. This has been steadily dropping for a number of years (20% since 1999), probably as a result of low cost airlines.
Ferry
Ferry
A ferry is a form of transportation, usually a boat, but sometimes a ship, used to carry primarily passengers, and sometimes vehicles and cargo as well, across a body of water. Most ferries operate on regular, frequent, return services...
connections from Great Britain to Ireland across the Irish Sea include the routes from Swansea
Swansea
Swansea is a coastal city and county in Wales. Swansea is in the historic county boundaries of Glamorgan. Situated on the sandy South West Wales coast, the county area includes the Gower Peninsula and the Lliw uplands...
to Cork
Cork (city)
Cork is the second largest city in the Republic of Ireland and the island of Ireland's third most populous city. It is the principal city and administrative centre of County Cork and the largest city in the province of Munster. Cork has a population of 119,418, while the addition of the suburban...
, Fishguard
Fishguard
Fishguard is a coastal town in Pembrokeshire, south-west Wales, with a population of 3,300 . The community of Fishguard and Goodwick had a population of 5043 at the 2001 census....
and Pembroke to Rosslare
Rosslare Europort
Rosslare Europort is a modern seaport located at Rosslare Harbour in County Wexford, Ireland, near the southeastern-most point of Ireland's coastline, handling passenger and freight ferries to and from Wales and France....
, Holyhead to Dún Laoghaire, Holyhead to Dublin, Stranraer
Stranraer
Stranraer is a town in the southwest of Scotland. It lies in the west of Dumfries and Galloway and in the county of Wigtownshire.Stranraer lies on the shores of Loch Ryan on the northern side of the isthmus joining the Rhins of Galloway to the mainland...
to Belfast
Belfast
Belfast is the capital of and largest city in Northern Ireland. By population, it is the 14th biggest city in the United Kingdom and second biggest on the island of Ireland . It is the seat of the devolved government and legislative Northern Ireland Assembly...
and Larne
Larne
Larne is a substantial seaport and industrial market town on the east coast of County Antrim, Northern Ireland with a population of 18,228 people in the 2001 Census. As of 2011, there are about 31,000 residents in the greater Larne area. It has been used as a seaport for over 1,000 years, and is...
, and Cairnryan
Cairnryan
Cairnryan is a small Scottish village in Dumfries and Galloway on the eastern shore of Loch Ryan. The village has been of vital importance in maritime history.-Ferry Port:...
to Larne. There is also a connection between Liverpool
Liverpool
Liverpool is a city and metropolitan borough of Merseyside, England, along the eastern side of the Mersey Estuary. It was founded as a borough in 1207 and was granted city status in 1880...
and Belfast via the Isle of Man
Isle of Man
The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is...
or direct from Birkenhead
Birkenhead
Birkenhead is a town within the Metropolitan Borough of Wirral in Merseyside, England. It is on the Wirral Peninsula, along the west bank of the River Mersey, opposite the city of Liverpool...
. The world's largest car ferry
RORO
Roll-on/roll-off ships are vessels designed to carry wheeled cargo such as automobiles, trucks, semi-trailer trucks, trailers or railroad cars that are driven on and off the ship on their own wheels...
, Ulysses
Ulysses (ship)
MS Ulysses is a RORO car ferry currently owned and operated by Irish Ferries. The ship was launched in March 2001 at Aker Finnyards shipyard in Rauma, Finland and services the Dublin - Holyhead route...
, is operated by Irish Ferries on the Dublin Port–Holyhead route; Stena Line
Stena Line
Stena Line is one of the world's largest ferry operators, with ferry services serving Scotland, Sweden, Northern Ireland, Denmark, Norway, England, Wales, Ireland, Germany, the Netherlands and Poland. Stena Line is a major unit of Stena AB, itself a part of the Stena Sphere, a grouping of Stena AB,...
also operates between Britain and Ireland. The Port of Barrow-in-Furness
Port of Barrow
The Port of Barrow refers to the enclosed dock system within the town of Barrow-in-Furness, England. Morecambe Bay is to the east of the port and the Irish Sea surrounds it to the south and west...
, despite being one of Britain's largest shipbuilding
Shipbuilding
Shipbuilding is the construction of ships and floating vessels. It normally takes place in a specialized facility known as a shipyard. Shipbuilders, also called shipwrights, follow a specialized occupation that traces its roots to before recorded history.Shipbuilding and ship repairs, both...
centres and being home to the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
's only submarine
Submarine
A submarine is a watercraft capable of independent operation below the surface of the water. It differs from a submersible, which has more limited underwater capability...
-building complex, is only a minor port.
"Irish Sea" is also the name of one of the BBC
BBC
The British Broadcasting Corporation is a British public service broadcaster. Its headquarters is at Broadcasting House in the City of Westminster, London. It is the largest broadcaster in the world, with about 23,000 staff...
's Shipping Forecast
Shipping Forecast
The Shipping Forecast is a four-times-daily BBC Radio broadcast of weather reports and forecasts for the seas around the coasts of the British Isles. It is produced by the Met Office and broadcast by BBC Radio 4 on behalf of the Maritime and Coastguard Agency. The forecasts sent over the Navtex...
areas defined by the coordinates:
54°50′N 05°05′W
54°45′N 05°45′W
52°30′N 06°15′W
52°00′N 05°05′W
There have been various tentative proposals for an Irish Sea Tunnel
Irish Sea Tunnel
An Irish Sea Tunnel is a proposed tunnel that would link the island of Ireland to Great Britain beneath the Irish Sea. It has been suggested in the past largely for political reasons. It would be a railway tunnel, similar to the Channel Tunnel beneath the English Channel...
.
During World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
the Irish Sea became known as "U-boat
U-boat
U-boat is the anglicized version of the German word U-Boot , itself an abbreviation of Unterseeboot , and refers to military submarines operated by Germany, particularly in World War I and World War II...
Alley", because the U-boats moved their emphasis from the Atlantic
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
to the Irish Sea after the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
entered the war in 1917.
- See also: Transport in IrelandTransport in IrelandMost of the transport system in Ireland is in public hands, either side of the Irish border. The Irish road network has evolved separately in the two jurisdictions Ireland is divided up into, while the Irish rail network was mostly created prior to the partition of Ireland.In the Republic of...
, Transport in the United KingdomTransport in the United KingdomTransport in the United Kingdom is facilitated with road, air, rail, and water networks. A radial road network totals of main roads, of motorways and of paved roads. The National Rail network of 10,072 route miles in Great Britain and 189 route miles in Northern Ireland carries over 18,000...
, Transport on the Isle of ManTransport on the Isle of ManThere are a number of transport services around the Isle of Man, Mostly consisting of paved roads, public transport, rail services, ports and an airport.-Roads:The island has a total of of public roads, all of which are paved...
Cities and towns
Below is a list of cities and towns around the Irish Sea coasts in order of size:| Rank | City/Town | County | Region/Province | Population | Country |
|---|---|---|---|---|---|
| 1 | Dublin | County Dublin County Dublin County Dublin is a county in Ireland. It is part of the Dublin Region and is also located in the province of Leinster. It is named after the city of Dublin which is the capital of Ireland. County Dublin was one of the first of the parts of Ireland to be shired by King John of England following the... |
Leinster Leinster Leinster is one of the Provinces of Ireland situated in the east of Ireland. It comprises the ancient Kingdoms of Mide, Osraige and Leinster. Following the Norman invasion of Ireland, the historic fifths of Leinster and Mide gradually merged, mainly due to the impact of the Pale, which straddled... |
505,739 | Ireland Republic of Ireland Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,... |
| 2 | Liverpool Liverpool Liverpool is a city and metropolitan borough of Merseyside, England, along the eastern side of the Mersey Estuary. It was founded as a borough in 1207 and was granted city status in 1880... |
Merseyside Merseyside Merseyside is a metropolitan county in North West England, with a population of 1,365,900. It encompasses the metropolitan area centred on both banks of the lower reaches of the Mersey Estuary, and comprises five metropolitan boroughs: Knowsley, St Helens, Sefton, Wirral, and the city of Liverpool... |
North West North West England North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East... |
447,500 | England England England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental... |
| 3 | Belfast Belfast Belfast is the capital of and largest city in Northern Ireland. By population, it is the 14th biggest city in the United Kingdom and second biggest on the island of Ireland . It is the seat of the devolved government and legislative Northern Ireland Assembly... |
County Antrim County Antrim County Antrim is one of six counties that form Northern Ireland, situated in the north-east of the island of Ireland. Adjoined to the north-east shore of Lough Neagh, the county covers an area of 2,844 km², with a population of approximately 616,000... |
Ulster Ulster Ulster is one of the four provinces of Ireland, located in the north of the island. In ancient Ireland, it was one of the fifths ruled by a "king of over-kings" . Following the Norman invasion of Ireland, the ancient kingdoms were shired into a number of counties for administrative and judicial... |
276,459 | Northern Ireland Northern Ireland Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west... |
| 5 | Blackpool Blackpool Blackpool is a borough, seaside town, and unitary authority area of Lancashire, in North West England. It is situated along England's west coast by the Irish Sea, between the Ribble and Wyre estuaries, northwest of Preston, north of Liverpool, and northwest of Manchester... |
Lancashire Lancashire Lancashire is a non-metropolitan county of historic origin in the North West of England. It takes its name from the city of Lancaster, and is sometimes known as the County of Lancaster. Although Lancaster is still considered to be the county town, Lancashire County Council is based in Preston... |
North West North West England North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East... |
142,900 | England England England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental... |
| 6 | Southport Southport Southport is a seaside town in the Metropolitan Borough of Sefton in Merseyside, England. During the 2001 census Southport was recorded as having a population of 90,336, making it the eleventh most populous settlement in North West England... |
Merseyside Merseyside Merseyside is a metropolitan county in North West England, with a population of 1,365,900. It encompasses the metropolitan area centred on both banks of the lower reaches of the Mersey Estuary, and comprises five metropolitan boroughs: Knowsley, St Helens, Sefton, Wirral, and the city of Liverpool... |
North West North West England North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East... |
99,456 | England England England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental... |
| 7 | Birkenhead Birkenhead Birkenhead is a town within the Metropolitan Borough of Wirral in Merseyside, England. It is on the Wirral Peninsula, along the west bank of the River Mersey, opposite the city of Liverpool... |
Merseyside Merseyside Merseyside is a metropolitan county in North West England, with a population of 1,365,900. It encompasses the metropolitan area centred on both banks of the lower reaches of the Mersey Estuary, and comprises five metropolitan boroughs: Knowsley, St Helens, Sefton, Wirral, and the city of Liverpool... |
North West North West England North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East... |
83,729 | England England England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental... |
| 8 | Bangor Bangor, County Down Bangor is a large town in County Down, Northern Ireland. It is a seaside resort on the southern side of Belfast Lough and within the Belfast Metropolitan Area. Bangor Marina is one of the largest in Ireland, and holds Blue Flag status... |
County Down County Down -Cities:*Belfast *Newry -Large towns:*Dundonald*Newtownards*Bangor-Medium towns:... |
Ulster Ulster Ulster is one of the four provinces of Ireland, located in the north of the island. In ancient Ireland, it was one of the fifths ruled by a "king of over-kings" . Following the Norman invasion of Ireland, the ancient kingdoms were shired into a number of counties for administrative and judicial... |
76,851 | Northern Ireland Northern Ireland Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west... |
| 9 | Barrow-in-Furness Barrow-in-Furness Barrow-in-Furness is an industrial town and seaport which forms about half the territory of the wider Borough of Barrow-in-Furness in the county of Cumbria, England. It lies north of Liverpool, northwest of Manchester and southwest from the county town of Carlisle... |
Cumbria Cumbria Cumbria , is a non-metropolitan county in North West England. The county and Cumbria County Council, its local authority, came into existence in 1974 after the passage of the Local Government Act 1972. Cumbria's largest settlement and county town is Carlisle. It consists of six districts, and in... |
North West North West England North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East... |
71,980 | England England England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental... |
| 10 | Wallasey Wallasey Wallasey is a town within the Metropolitan Borough of Wirral, in Merseyside, England, on the mouth of the River Mersey, at the northeastern corner of the Wirral Peninsula... |
Merseyside Merseyside Merseyside is a metropolitan county in North West England, with a population of 1,365,900. It encompasses the metropolitan area centred on both banks of the lower reaches of the Mersey Estuary, and comprises five metropolitan boroughs: Knowsley, St Helens, Sefton, Wirral, and the city of Liverpool... |
North West North West England North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East... |
58,710 | England England England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental... |
| 11 | Morecambe Morecambe Morecambe is a resort town and civil parish within the City of Lancaster in Lancashire, England. As of 2001 it has a resident population of 38,917. It faces into Morecambe Bay... |
Lancashire Lancashire Lancashire is a non-metropolitan county of historic origin in the North West of England. It takes its name from the city of Lancaster, and is sometimes known as the County of Lancaster. Although Lancaster is still considered to be the county town, Lancashire County Council is based in Preston... |
North West North West England North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East... |
45,000 | England England England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental... |
| 12 | Lytham St Annes Lytham St Annes Lytham St Annes is a conurbation in the Fylde district of Lancashire, England. The neighbouring towns of Lytham and St-Anne's-on-the-Sea have grown together and now form a seaside resort... |
Lancashire Lancashire Lancashire is a non-metropolitan county of historic origin in the North West of England. It takes its name from the city of Lancaster, and is sometimes known as the County of Lancaster. Although Lancaster is still considered to be the county town, Lancashire County Council is based in Preston... |
North West North West England North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East... |
41,330 | England England England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental... |
| 13 | Drogheda Drogheda Drogheda is an industrial and port town in County Louth on the east coast of Ireland, 56 km north of Dublin. It is the last bridging point on the River Boyne before it enters the Irish Sea.... |
County Louth County Louth County Louth is a county of Ireland. It is part of the Border Region and is also located in the province of Leinster. It is named after the town of Louth. Louth County Council is the local authority for the county... |
Leinster Leinster Leinster is one of the Provinces of Ireland situated in the east of Ireland. It comprises the ancient Kingdoms of Mide, Osraige and Leinster. Following the Norman invasion of Ireland, the historic fifths of Leinster and Mide gradually merged, mainly due to the impact of the Pale, which straddled... |
35,190 | Ireland Republic of Ireland Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,... |
| 14 | Dundalk Dundalk Dundalk is the county town of County Louth in Ireland. It is situated where the Castletown River flows into Dundalk Bay. The town is close to the border with Northern Ireland and equi-distant from Dublin and Belfast. The town's name, which was historically written as Dundalgan, has associations... |
County Louth County Louth County Louth is a county of Ireland. It is part of the Border Region and is also located in the province of Leinster. It is named after the town of Louth. Louth County Council is the local authority for the county... |
Leinster Leinster Leinster is one of the Provinces of Ireland situated in the east of Ireland. It comprises the ancient Kingdoms of Mide, Osraige and Leinster. Following the Norman invasion of Ireland, the historic fifths of Leinster and Mide gradually merged, mainly due to the impact of the Pale, which straddled... |
35,085 | Ireland Republic of Ireland Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,... |
| 15 | Rhyl Rhyl Rhyl is a seaside resort town and community situated on the north east coast of Wales, in the county of Denbighshire , at the mouth of the River Clwyd . To the west is the suburb of Kinmel Bay, with the resort of Towyn further west, Prestatyn to the east and Rhuddlan to the south... |
Denbighshire Denbighshire Denbighshire is a county in north-east Wales. It is named after the historic county of Denbighshire, but has substantially different borders. Denbighshire has the distinction of being the oldest inhabited part of Wales. Pontnewydd Palaeolithic site has remains of Neanderthals from 225,000 years... |
Clwyd Clwyd Clwyd is a preserved county of Wales, situated in the north-east, bordering England with Cheshire to its east, Shropshire to the south-east, and the Welsh counties of Gwynedd to its immediate west and Powys to the south. It additionally shares a maritime border with the metropolitan county of... , Wales Wales Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²... |
35,000 | Wales Wales Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²... |
| 17 | Bray Bray Bray is a town in north County Wicklow, Ireland. It is a busy urban centre and seaside resort, with a population of 31,901 making it the fourth largest in Ireland as of the 2006 census... |
County Wicklow County Wicklow County Wicklow is a county in Ireland. It is part of the Mid-East Region and is also located in the province of Leinster. It is named after the town of Wicklow, which derives from the Old Norse name Víkingalág or Wykynlo. Wicklow County Council is the local authority for the county... |
Leinster Leinster Leinster is one of the Provinces of Ireland situated in the east of Ireland. It comprises the ancient Kingdoms of Mide, Osraige and Leinster. Following the Norman invasion of Ireland, the historic fifths of Leinster and Mide gradually merged, mainly due to the impact of the Pale, which straddled... |
31,901 | Ireland Republic of Ireland Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,... |
| 18 | Thornton-Cleveleys Thornton-Cleveleys Thornton–Cleveleys is an unparished area in the English local government district of Wyre, Lancashire, covering the towns of Thornton and Cleveleys. It forms part of the Greater Blackpool area.... |
Lancashire Lancashire Lancashire is a non-metropolitan county of historic origin in the North West of England. It takes its name from the city of Lancaster, and is sometimes known as the County of Lancaster. Although Lancaster is still considered to be the county town, Lancashire County Council is based in Preston... |
North West North West England North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East... |
31,157 | England England England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental... |
| 19 | Colwyn Bay Colwyn Bay - Demography :Prior to local government reorganisation on 1 April 1974 Colwyn Bay was a municipal borough with a population of c.25,000, but in 1974 this designation disappeared leaving five separate parishes, known as communities in Wales, of which the one bearing the name Colwyn Bay encompassed... |
Conwy Conwy Conwy is a walled market town and community in Conwy County Borough on the north coast of Wales. The town, which faces Deganwy across the River Conwy, formerly lay in Gwynedd and prior to that in Caernarfonshire. Conwy has a population of 14,208... |
Clwyd Clwyd Clwyd is a preserved county of Wales, situated in the north-east, bordering England with Cheshire to its east, Shropshire to the south-east, and the Welsh counties of Gwynedd to its immediate west and Powys to the south. It additionally shares a maritime border with the metropolitan county of... , Wales Wales Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²... |
30,265 | Wales Wales Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²... |
| 20 | Carrickfergus Carrickfergus Carrickfergus , known locally and colloquially as "Carrick", is a large town in County Antrim, Northern Ireland. It is located on the north shore of Belfast Lough, from Belfast. The town had a population of 27,201 at the 2001 Census and takes its name from Fergus Mór mac Eirc, the 6th century king... |
County Antrim County Antrim County Antrim is one of six counties that form Northern Ireland, situated in the north-east of the island of Ireland. Adjoined to the north-east shore of Lough Neagh, the county covers an area of 2,844 km², with a population of approximately 616,000... |
Ulster Ulster Ulster is one of the four provinces of Ireland, located in the north of the island. In ancient Ireland, it was one of the fifths ruled by a "king of over-kings" . Following the Norman invasion of Ireland, the ancient kingdoms were shired into a number of counties for administrative and judicial... |
27,201 | Northern Ireland Northern Ireland Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west... |
| 21 | Fleetwood Fleetwood Fleetwood is a town within the Wyre district of Lancashire, England, lying at the northwest corner of the Fylde. It had a population of 26,840 people at the 2001 Census. It forms part of the Greater Blackpool conurbation. The town was the first planned community of the Victorian era... |
Lancashire Lancashire Lancashire is a non-metropolitan county of historic origin in the North West of England. It takes its name from the city of Lancaster, and is sometimes known as the County of Lancaster. Although Lancaster is still considered to be the county town, Lancashire County Council is based in Preston... |
North West North West England North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East... |
26,840 | England England England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental... |
| 22 | Douglas Douglas, Isle of Man right|thumb|250px|Douglas Promenade, which runs nearly the entire length of beachfront in Douglasright|thumb|250px|Sea terminal in DouglasDouglas is the capital and largest town of the Isle of Man, with a population of 26,218 people . It is located at the mouth of the River Douglas, and a sweeping... |
N/A | Isle of Man Isle of Man The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is... |
26,218 | Isle of Man Isle of Man The Isle of Man , otherwise known simply as Mann , is a self-governing British Crown Dependency, located in the Irish Sea between the islands of Great Britain and Ireland, within the British Isles. The head of state is Queen Elizabeth II, who holds the title of Lord of Mann. The Lord of Mann is... |
| 20 | Workington Workington Workington is a town, civil parish and port on the west coast of Cumbria, England, at the mouth of the River Derwent. Lying within the Borough of Allerdale, Workington is southwest of Carlisle, west of Cockermouth, and southwest of Maryport... |
Cumbria Cumbria Cumbria , is a non-metropolitan county in North West England. The county and Cumbria County Council, its local authority, came into existence in 1974 after the passage of the Local Government Act 1972. Cumbria's largest settlement and county town is Carlisle. It consists of six districts, and in... |
North West North West England North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East... |
25,978 | England England England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental... |
| 23 | Whitehaven Whitehaven Whitehaven is a small town and port on the coast of Cumbria, England, which lies equidistant between the county's two largest settlements, Carlisle and Barrow-in-Furness, and is served by the Cumbrian Coast Line and the A595 road... |
Cumbria Cumbria Cumbria , is a non-metropolitan county in North West England. The county and Cumbria County Council, its local authority, came into existence in 1974 after the passage of the Local Government Act 1972. Cumbria's largest settlement and county town is Carlisle. It consists of six districts, and in... |
North West North West England North West England, informally known as The North West, is one of the nine official regions of England.North West England had a 2006 estimated population of 6,853,201 the third most populated region after London and the South East... |
25,500 | England England England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental... |
| 24 | Dún Laoghaire Dún Laoghaire Dún Laoghaire or Dún Laoire , sometimes anglicised as "Dunleary" , is a suburban seaside town in County Dublin, Ireland, about twelve kilometres south of Dublin city centre. It is the county town of Dun Laoghaire-Rathdown County and a major port of entry from Great Britain... |
Dun Laoghaire-Rathdown Dun Laoghaire-Rathdown Dún Laoghaire–Rathdown is a county in Ireland. It is one of three smaller counties into which County Dublin was divided in 1994. Located to the south-east of Dublin city, its county seat is the town of Dún Laoghaire. It is one of the four constituent parts of the Dublin Region... |
Leinster Leinster Leinster is one of the Provinces of Ireland situated in the east of Ireland. It comprises the ancient Kingdoms of Mide, Osraige and Leinster. Following the Norman invasion of Ireland, the historic fifths of Leinster and Mide gradually merged, mainly due to the impact of the Pale, which straddled... |
23,857 | Ireland Republic of Ireland Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,... |
| 25 | Llandudno Llandudno Llandudno is a seaside resort and town in Conwy County Borough, Wales. In the 2001 UK census it had a population of 20,090 including that of Penrhyn Bay and Penrhynside, which are within the Llandudno Community... |
Conwy Conwy Conwy is a walled market town and community in Conwy County Borough on the north coast of Wales. The town, which faces Deganwy across the River Conwy, formerly lay in Gwynedd and prior to that in Caernarfonshire. Conwy has a population of 14,208... |
Clwyd Clwyd Clwyd is a preserved county of Wales, situated in the north-east, bordering England with Cheshire to its east, Shropshire to the south-east, and the Welsh counties of Gwynedd to its immediate west and Powys to the south. It additionally shares a maritime border with the metropolitan county of... , Wales Wales Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²... |
20,090 | Wales Wales Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²... |
| 26 | Larne Larne Larne is a substantial seaport and industrial market town on the east coast of County Antrim, Northern Ireland with a population of 18,228 people in the 2001 Census. As of 2011, there are about 31,000 residents in the greater Larne area. It has been used as a seaport for over 1,000 years, and is... |
County Antrim County Antrim County Antrim is one of six counties that form Northern Ireland, situated in the north-east of the island of Ireland. Adjoined to the north-east shore of Lough Neagh, the county covers an area of 2,844 km², with a population of approximately 616,000... |
Ulster Ulster Ulster is one of the four provinces of Ireland, located in the north of the island. In ancient Ireland, it was one of the fifths ruled by a "king of over-kings" . Following the Norman invasion of Ireland, the ancient kingdoms were shired into a number of counties for administrative and judicial... |
18,228 | Northern Ireland Northern Ireland Northern Ireland is one of the four countries of the United Kingdom. Situated in the north-east of the island of Ireland, it shares a border with the Republic of Ireland to the south and west... |
| 27 | Wexford Wexford Wexford is the county town of County Wexford, Ireland. It is situated near the southeastern corner of Ireland, close to Rosslare Europort. The town is connected to Dublin via the M11/N11 National Primary Route, and the national rail network... |
County Wexford County Wexford County Wexford is a county in Ireland. It is part of the South-East Region and is also located in the province of Leinster. It is named after the town of Wexford. In pre-Norman times it was part of the Kingdom of Uí Cheinnselaig, whose capital was at Ferns. Wexford County Council is the local... |
Leinster Leinster Leinster is one of the Provinces of Ireland situated in the east of Ireland. It comprises the ancient Kingdoms of Mide, Osraige and Leinster. Following the Norman invasion of Ireland, the historic fifths of Leinster and Mide gradually merged, mainly due to the impact of the Pale, which straddled... |
18,163 | Ireland Republic of Ireland Ireland , described as the Republic of Ireland , is a sovereign state in Europe occupying approximately five-sixths of the island of the same name. Its capital is Dublin. Ireland, which had a population of 4.58 million in 2011, is a constitutional republic governed as a parliamentary democracy,... |
Origin
The Irish Sea has undergone a series of dramatic changes over the last 20,000 years as the last glacial period ended and was replaced by warmer conditions. At the height of the glaciation the central part of the modern sea was probably a long freshwaterFreshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...
lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
. As the ice
Ice
Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...
retreated 10,000 years ago the lake reconnected to the sea, becoming brackish and then fully saline
Saline water
Saline water is a general term for water that contains a significant concentration of dissolved salts . The concentration is usually expressed in parts per million of salt....
once again.
Environment
Biodiversity
The most accessible and possibly the greatest wildlifeWildlife
Wildlife includes all non-domesticated plants, animals and other organisms. Domesticating wild plant and animal species for human benefit has occurred many times all over the planet, and has a major impact on the environment, both positive and negative....
resource of the Irish Sea lies in its estuaries: particularly the Dee Estuary
Dee Estuary
The Dee Estuary is a large estuary by means of which the River Dee flows into Liverpool Bay. The estuary starts near Shotton after a five miles 'canalised' section and the river soon swells to be several miles wide forming the boundary between the Wirral Peninsula in north-west England and...
, the Mersey Estuary, the Ribble Estuary
Ribble and Alt Estuaries
The Ribble and Alt Estuaries lie on the Irish Sea coast of the counties of Lancashire and Merseyside in north-west England, and form the boundaries of a number of nature preservation schemes. -Protected area:...
, Morecambe Bay
Morecambe Bay
Morecambe Bay is a large bay in northwest England, nearly due east of the Isle of Man and just to the south of the Lake District National Park. It is the largest expanse of intertidal mudflats and sand in the United Kingdom, covering a total area of 310 km².-Natural features:The rivers Leven,...
, the Solway Firth
Solway Firth
The Solway Firth is a firth that forms part of the border between England and Scotland, between Cumbria and Dumfries and Galloway. It stretches from St Bees Head, just south of Whitehaven in Cumbria, to the Mull of Galloway, on the western end of Dumfries and Galloway. The Isle of Man is also very...
, Loch Ryan
Loch Ryan
Loch Ryan is a Scottish sea loch that acts as an important natural harbour for shipping, providing calm waters for ferries operating between Scotland and Northern Ireland...
, the Firth of Clyde
Firth of Clyde
The Firth of Clyde forms a large area of coastal water, sheltered from the Atlantic Ocean by the Kintyre peninsula which encloses the outer firth in Argyll and Ayrshire, Scotland. The Kilbrannan Sound is a large arm of the Firth of Clyde, separating the Kintyre Peninsula from the Isle of Arran.At...
, Belfast Lough
Belfast Lough
Belfast Lough is a large, natural intertidal sea lough at the mouth of the River Lagan on the east coast of Northern Ireland. The inner part of the lough comprises a series of mudflats and lagoons. The outer lough is restricted to mainly rocky shores with some small sandy bays...
, Strangford Lough
Strangford Lough
Strangford Lough, sometimes Strangford Loch, is a large sea loch or inlet in County Down, Northern Ireland. It is separated from the Irish Sea by the Ards Peninsula. The name Strangford is derived ; describing the fast-flowing narrows at its mouth...
, Carlingford Lough
Carlingford Lough
Carlingford Lough is a glacial fjord or sea inlet that forms part of the border between Northern Ireland to the north and the Republic of Ireland to the south. On its northern shore is County Down and on its southern shore is County Louth...
, Dundalk Bay
Dundalk Bay
Dundalk Bay is a large , exposed estuary on the east coast of Ireland.The inner bay is shallow, sandy and intertidal, though it slopes into a deeper area 2km from the transitional water boundary. It is predominantly influenced by the sea, though several rivers drain into the bay from the west...
, Dublin Bay
Dublin Bay
Dublin Bay is a C-shaped inlet of the Irish Sea on the east coast of Ireland. The bay is about 10 kilometres wide along its north-south base, and 7 km in length to its apex at the centre of the city of Dublin; stretching from Howth Head in the north to Dalkey Point in the south...
and Wexford Harbour
Wexford Harbour
Wexford Harbour in County Wexford, Ireland is the natural harbour at the mouth of the River Slaney. The estuary originally was about ten miles wide at its widest point, with large mud flats on both sides. These were known as the North Slob and the South Slob from the Irish word slab, meaning mud...
. However, a lot of wildlife also depends on the cliff
Cliff
In geography and geology, a cliff is a significant vertical, or near vertical, rock exposure. Cliffs are formed as erosion landforms due to the processes of erosion and weathering that produce them. Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually...
s, salt marsh
Salt marsh
A salt marsh is an environment in the upper coastal intertidal zone between land and salt water or brackish water, it is dominated by dense stands of halophytic plants such as herbs, grasses, or low shrubs. These plants are terrestrial in origin and are essential to the stability of the salt marsh...
es and sand dunes of the adjoining shore
Shore
A shore or shoreline is the fringe of land at the edge of a large body of water, such as an ocean, sea, or lake. In Physical Oceanography a shore is the wider fringe that is geologically modified by the action of the body of water past and present, while the beach is at the edge of the shore,...
s, the seabed
Seabed
The seabed is the bottom of the ocean.- Ocean structure :Most of the oceans have a common structure, created by common physical phenomena, mainly from tectonic movement, and sediment from various sources...
and the open sea itself.
The information on the invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s of the seabed of the Irish Sea is rather patchy because it is difficult to survey such a large area, where underwater visibility is often poor and information often depends upon looking at material brought up from the seabed in mechanical grabs. However, the groupings of animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...
s present depend to a large extent on whether the seabed is composed of rock
Rock (geology)
In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...
, boulder
Boulder
In geology, a boulder is a rock with grain size of usually no less than 256 mm diameter. While a boulder may be small enough to move or roll manually, others are extremely massive....
s, gravel
Gravel
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...
, sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...
, mud
Mud
Mud is a mixture of water and some combination of soil, silt, and clay. Ancient mud deposits harden over geological time to form sedimentary rock such as shale or mudstone . When geological deposits of mud are formed in estuaries the resultant layers are termed bay muds...
or even peat
Peat
Peat is an accumulation of partially decayed vegetation matter or histosol. Peat forms in wetland bogs, moors, muskegs, pocosins, mires, and peat swamp forests. Peat is harvested as an important source of fuel in certain parts of the world...
. In the soft sediment
Sediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
s seven types of community have been provisionally identified, variously dominated by brittle-stars, sea urchin
Sea urchin
Sea urchins or urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum. They inhabit all oceans. Their shell, or "test", is round and spiny, typically from across. Common colors include black and dull...
s, worm
Worm
The term worm refers to an obsolete taxon used by Carolus Linnaeus and Jean-Baptiste Lamarck for all non-arthropod invertebrate animals, and stems from the Old English word wyrm. Currently it is used to describe many different distantly-related animals that typically have a long cylindrical...
s, mussel
Mussel
The common name mussel is used for members of several families of clams or bivalvia mollusca, from saltwater and freshwater habitats. These groups have in common a shell whose outline is elongated and asymmetrical compared with other edible clams, which are often more or less rounded or oval.The...
s, tellins
Tellina
Tellina is a widely distributed genus of marine bivalve molluscs, in the family Tellinidae.- Species :* Tellina aequistriata Say, 1824: striate tellin* Tellina agilis Stimpson, 1857: northern dwarf tellin, northern dwarf-tellin...
, furrow-shell
Peppery furrow shell
The peppery furrow shell, Scrobicularia plana, also known as a sand gaper, is the only species currently recognized by ITIS in the genus Scrobicularia; however some sources recognise other species such as Scrobicularia cottardi. It is a bivalve mollusc commonly found on sandy or muddy sea coasts...
s, and tower-shells.
Parts of the bed of the Irish Sea are very rich in wildlife. The seabed southwest of the Isle of Man is particularly noted for its rarities and diversity, as are the horse mussel
Horse mussel
Not to be confused with Modiolus modiolus also known as thehorse mussel.The horse mussel, Atrina squamifera, is a species of bivalve pen shell. It is a marine mollusc in the family Pinnidae...
beds of Strangford Lough. Scallop
Scallop
A scallop is a marine bivalve mollusk of the family Pectinidae. Scallops are a cosmopolitan family, found in all of the world's oceans. Many scallops are highly prized as a food source...
s and queen scallop
Queen scallop
The Queen Scallop, scientific name Aequipecten opercularis, is a medium-sized species of scallop, an edible marine bivalve mollusk in the family Pectinidae, the scallops.-Description:...
s are found in more gravelly areas. In the estuaries, where the bed is more sandy or muddy, the number of species is smaller but the size of their populations is larger. Brown shrimp, cockle
Cockle (bivalve)
Cockle is the common name for a group of small, edible, saltwater clams, marine bivalve molluscs in the family Cardiidae.Various species of cockles live in sandy sheltered beaches throughout the world....
s and edible mussels support local fisheries in Morecambe Bay and the Dee Estuary and the estuaries are also important as nurseries for flatfish
Flatfish
The flatfish are an order of ray-finned fish, also called the Heterosomata, sometimes classified as a suborder of Perciformes. In many species, both eyes lie on one side of the head, one or the other migrating through and around the head during development...
, herring
Herring
Herring is an oily fish of the genus Clupea, found in the shallow, temperate waters of the North Pacific and the North Atlantic oceans, including the Baltic Sea. Three species of Clupea are recognized. The main taxa, the Atlantic herring and the Pacific herring may each be divided into subspecies...
and sea bass
European seabass
The European seabass, Dicentrarchus labrax, also known as Morone labrax, is a primarily ocean-going fish that sometimes enters brackish and fresh waters. It is also known as the sea dace...
. Muddy seabeds in deeper waters are home to populations of the Dublin Bay prawn, also known as "scampi".
The open sea is a complex habitat in its own right. It exists in three spatial dimensions and also varies over time and tide. For example, where freshwater flows into the Irish Sea in river estuaries its influence can extend far offshore as the freshwater is lighter and "floats" on top of the much larger body of saltwater until wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...
and temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
changes mix it in. Similarly, warmer water is less dense and seawater warmed in the inter-tidal zone may "float" on the colder offshore water. The amount of light penetrating the seawater also varies with depth and turbidity. This leads to differing populations of plankton
Plankton
Plankton are any drifting organisms that inhabit the pelagic zone of oceans, seas, or bodies of fresh water. That is, plankton are defined by their ecological niche rather than phylogenetic or taxonomic classification...
in different parts of the sea and varying communities of animals that feed on these populations. However, increasing seasonal storm
Storm
A storm is any disturbed state of an astronomical body's atmosphere, especially affecting its surface, and strongly implying severe weather...
iness leads to greater mixing of water and tends to break down these divisions, which are more apparent when the weather is calm for long periods.
Plankton includes bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
, plant
Plant
Plants are living organisms belonging to the kingdom Plantae. Precise definitions of the kingdom vary, but as the term is used here, plants include familiar organisms such as trees, flowers, herbs, bushes, grasses, vines, ferns, mosses, and green algae. The group is also called green plants or...
s (phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
) and animals (zooplankton
Zooplankton
Zooplankton are heterotrophic plankton. Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word "zooplankton" is derived from the Greek zoon , meaning "animal", and , meaning "wanderer" or "drifter"...
) that drift in the sea. Most are microscopic, but some, such as the various species of jellyfish
Jellyfish
Jellyfish are free-swimming members of the phylum Cnidaria. Medusa is another word for jellyfish, and refers to any free-swimming jellyfish stages in the phylum Cnidaria...
and sea gooseberry
Ctenophore
The Ctenophora are a phylum of animals that live in marine waters worldwide. Their most distinctive feature is the "combs", groups of cilia that they use for swimming, and they are the largest animals that swim by means of cilia – adults of various species range from a few millimeters to in size...
, can be much bigger.
Diatom
Diatom
Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons , fans , zigzags , or stellate colonies . Diatoms are producers within the food chain...
s and dinoflagellate
Dinoflagellate
The dinoflagellates are a large group of flagellate protists. Most are marine plankton, but they are common in fresh water habitats as well. Their populations are distributed depending on temperature, salinity, or depth...
s dominate the phytoplankton. Although they are microscopic plants, diatoms have hard shells and dinoflagellates have little tail
Tail
The tail is the section at the rear end of an animal's body; in general, the term refers to a distinct, flexible appendage to the torso. It is the part of the body that corresponds roughly to the sacrum and coccyx in mammals, reptiles, and birds...
s that propel them through the water. Phytoplankton populations in the Irish Sea have a spring "bloom" every April and May, when the seawater is generally at its greenest.
Crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, especially copepod
Copepod
Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat. Some species are planktonic , some are benthic , and some continental species may live in limno-terrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests,...
s, dominate the zooplankton. However, many animals of the seabed, the open sea and the seashore spend their juvenile stages as part of the zooplankton. The whole plankton "soup" is vitally important, directly or indirectly, as a food source for most species in the Irish Sea, even the largest. The enormous basking shark
Basking shark
The basking shark is the second largest living fish, after the whale shark. It is a cosmopolitan migratory species, found in all the world's temperate oceans. It is a slow moving and generally harmless filter feeder and has anatomical adaptations to filter feeding, such as a greatly enlarged...
, for example, lives entirely on plankton and the leatherback turtle's main food is jellyfish.
A colossal diversity of invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
live in the Irish Sea and its surrounding coastline, ranging from flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...
-like fan-worms to predatory swimming crabs
Portunidae
Portunidae is a family of crabs which contains the swimming crabs.-Description:Portunid crabs are characterised by the flattening of the fifth pair of legs into broad paddles, which are used for swimming...
to large chameleon
Chameleon
Chameleons are a distinctive and highly specialized clade of lizards. They are distinguished by their parrot-like zygodactylous feet, their separately mobile and stereoscopic eyes, their very long, highly modified, and rapidly extrudable tongues, their swaying gait, the possession by many of a...
-like cuttlefish
Cuttlefish
Cuttlefish are marine animals of the order Sepiida. They belong to the class Cephalopoda . Despite their name, cuttlefish are not fish but molluscs....
.
Some of the most significant for other wildlife are the reef-building species like the inshore horse mussel of Strangford Lough and the inter-tidal honeycomb worm of Morecambe Bay, Cumbria
Cumbria
Cumbria , is a non-metropolitan county in North West England. The county and Cumbria County Council, its local authority, came into existence in 1974 after the passage of the Local Government Act 1972. Cumbria's largest settlement and county town is Carlisle. It consists of six districts, and in...
and Lancashire
Lancashire
Lancashire is a non-metropolitan county of historic origin in the North West of England. It takes its name from the city of Lancaster, and is sometimes known as the County of Lancaster. Although Lancaster is still considered to be the county town, Lancashire County Council is based in Preston...
. These build up large structures over many years and, in turn, provide surfaces, nooks and crannies where other marine animals and plants may become established and live out some or all of their lives.
There are quite regular records of live and stranded leatherback turtle in and around the Irish Sea. This species travels north to the waters off the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...
every year following the swarms of jellyfish that form its prey. Loggerhead turtle, Ridley sea turtle
Ridley sea turtle
Ridley sea turtles are a genus of sea turtles comprising two species: Kemp's ridley sea turtle and the olive ridley sea turtle.Kemp's ridley sea turtles are currently on the New York and federal endangered species lists.-Anatomy:...
and green turtle are found very occasionally in the Irish Sea but are generally unwell or dead when discovered. They have strayed or been swept out of their natural range further south into colder waters.
The estuaries of the Irish Sea are of international importance for bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
s. They are vital feeding grounds on migration
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
flyways for shorebirds travelling between the Arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...
and Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. Others depend on the milder climate as a refuge when continental Europe is in the grip of winter.
Twenty-one species of seabird
Seabird
Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar adaptations...
are reported as regularly nesting on beach
Beach
A beach is a geological landform along the shoreline of an ocean, sea, lake or river. It usually consists of loose particles which are often composed of rock, such as sand, gravel, shingle, pebbles or cobblestones...
es or cliffs around the Irish Sea. Huge populations of the sea duck, common scoter
Common Scoter
The Common Scoter is a large sea duck, 43-54 cm in length, which breeds over the far north of Europe and Asia east to the Olenyok River. The American/E Siberian M. americana is sometimes considered a subspecies of M. nigra.It winters further south in temperate zones, on the coasts of Europe as...
, spend winters feeding in shallow waters off eastern Ireland, Lancashire and North Wales
North Wales
North Wales is the northernmost unofficial region of Wales. It is bordered to the south by the counties of Ceredigion and Powys in Mid Wales and to the east by the counties of Shropshire in the West Midlands and Cheshire in North West England...
.
Whale
Whale
Whale is the common name for various marine mammals of the order Cetacea. The term whale sometimes refers to all cetaceans, but more often it excludes dolphins and porpoises, which belong to suborder Odontoceti . This suborder also includes the sperm whale, killer whale, pilot whale, and beluga...
s, dolphin
Dolphin
Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from and , up to and . They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating...
s and porpoise
Porpoise
Porpoises are small cetaceans of the family Phocoenidae; they are related to whales and dolphins. They are distinct from dolphins, although the word "porpoise" has been used to refer to any small dolphin, especially by sailors and fishermen...
s all frequent the Irish Sea, but knowledge of how many there may be and where they go is somewhat sketchy. About a dozen species have been recorded since 1980, but only three are seen fairly often. These are the harbour porpoise
Harbour Porpoise
The harbour porpoise is one of six species of porpoise. It is one of the smallest marine mammals. As its name implies, it stays close to coastal areas or river estuaries, and as such, is the most familiar porpoise to whale watchers. This porpoise often ventures up rivers, and has been seen...
, bottlenose dolphin
Bottlenose Dolphin
Bottlenose dolphins, the genus Tursiops, are the most common and well-known members of the family Delphinidae, the family of oceanic dolphins. Recent molecular studies show the genus contains two species, the common bottlenose dolphin and the Indo-Pacific bottlenose dolphin , instead of one...
and common dolphin
Common dolphin
The common dolphin is the name given to two species of dolphin making up the genus Delphinus.Prior to the mid-1990s, most taxonomists only recognised one species in this genus, the common dolphin Delphinus delphis...
. The more rarely seen species are minke whale
Minke Whale
Minke whale , or lesser rorqual, is a name given to two species of marine mammal belonging to a clade within the suborder of baleen whales. The minke whale was given its official designation by Lacepède in 1804, who described a dwarf form of Balænoptera acuto-rostrata...
, fin whale
Fin Whale
The fin whale , also called the finback whale, razorback, or common rorqual, is a marine mammal belonging to the suborder of baleen whales. It is the second longest whale and the sixth largest living animal after the blue whale, bowhead whale, and right whales, growing to nearly 27 metres long...
, sei whale
Sei Whale
The sei whale , Balaenoptera borealis, is a baleen whale, the third-largest rorqual after the blue whale and the fin whale. It inhabits most oceans and adjoining seas, and prefers deep offshore waters. It avoids polar and tropical waters and semi-enclosed bodies of water...
, sperm whale
Sperm Whale
The sperm whale, Physeter macrocephalus, is a marine mammal species, order Cetacea, a toothed whale having the largest brain of any animal. The name comes from the milky-white waxy substance, spermaceti, found in the animal's head. The sperm whale is the only living member of genus Physeter...
, northern bottlenose whale, long-finned pilot whale
Long-finned Pilot Whale
The long-finned pilot whale is one of the two species of cetacean in the genus Globicephala. It belongs to the oceanic dolphin family , though its behavior is closer to that of the larger whales.-Description:...
, orca
Orca
The killer whale , commonly referred to as the orca, and less commonly as the blackfish, is a toothed whale belonging to the oceanic dolphin family. Killer whales are found in all oceans, from the frigid Arctic and Antarctic regions to tropical seas...
, white-beaked dolphin
White-beaked Dolphin
The White-beaked dolphin is a marine mammal belonging to the family Delphinidae in the suborder Odontoceti .-Taxonomy:...
, striped dolphin
Striped Dolphin
The Striped Dolphin is an extensively studied dolphin that is found in temperate and tropical waters of all the world's oceans.-Taxonomy:...
and Risso's dolphin
Risso's Dolphin
Risso's dolphin is the only species of dolphin in the genus Grampus.-Taxonomy:Risso's dolphin is named after Antoine Risso, whose description formed the basis of the first public description of the animal, by Georges Cuvier, in 1812...
.
The common or harbour seal and the grey seal
Grey Seal
The grey seal is found on both shores of the North Atlantic Ocean. It is a large seal of the family Phocidae or "true seals". It is the only species classified in the genus Halichoerus...
are both resident in the Irish Sea. Common seal
Pinniped
Pinnipeds or fin-footed mammals are a widely distributed and diverse group of semiaquatic marine mammals comprising the families Odobenidae , Otariidae , and Phocidae .-Overview: Pinnipeds are typically sleek-bodied and barrel-shaped...
s breed in Strangford Lough, grey seals in southwest Wales and, in small numbers, on the Isle of Man. Grey seals haul out, but do not breed, off Hilbre
Hilbre Island
Hilbre Island is the largest of a group of three islands at the mouth of the estuary of the River Dee, which is a part of the estuary Site of Special Scientific Interest. The island is currently uninhabited....
and Walney
Walney Island
The Isle of Walney, also known as Walney Island, is an island in the United Kingdom which lies off the west coast of England, at the northern tip of Morecambe Bay. It forms part of the Borough of Barrow-in-Furness, and it is separated from the mainland at Barrow by Walney Channel, a narrow channel...
islands, Merseyside
Merseyside
Merseyside is a metropolitan county in North West England, with a population of 1,365,900. It encompasses the metropolitan area centred on both banks of the lower reaches of the Mersey Estuary, and comprises five metropolitan boroughs: Knowsley, St Helens, Sefton, Wirral, and the city of Liverpool...
, the Wirral
Wirral Peninsula
Wirral or the Wirral is a peninsula in North West England. It is bounded by three bodies of water: to the west by the River Dee, forming a boundary with Wales, to the east by the River Mersey and to the north by the Irish Sea. Both terms "Wirral" and "the Wirral" are used locally , although the...
, Barrow-in-Furness Borough, and Cumbria.
Radioactivity
The Irish Sea has been described by GreenpeaceGreenpeace
Greenpeace is a non-governmental environmental organization with offices in over forty countries and with an international coordinating body in Amsterdam, The Netherlands...
as the most radioactively contaminated
Radioactive contamination
Radioactive contamination, also called radiological contamination, is radioactive substances on surfaces, or within solids, liquids or gases , where their presence is unintended or undesirable, or the process giving rise to their presence in such places...
sea in the world with some "eight million litre
Litre
pic|200px|right|thumb|One litre is equivalent to this cubeEach side is 10 cm1 litre water = 1 kilogram water The litre is a metric system unit of volume equal to 1 cubic decimetre , to 1,000 cubic centimetres , and to 1/1,000 cubic metre...
s of nuclear waste" discharged into it each day from Sellafield
Sellafield
Sellafield is a nuclear reprocessing site, close to the village of Seascale on the coast of the Irish Sea in Cumbria, England. The site is served by Sellafield railway station. Sellafield is an off-shoot from the original nuclear reactor site at Windscale which is currently undergoing...
reprocessing plants, contaminating seawater, sediments and marine life.
Low-level radioactive
Radioactive decay
Radioactive decay is the process by which an atomic nucleus of an unstable atom loses energy by emitting ionizing particles . The emission is spontaneous, in that the atom decays without any physical interaction with another particle from outside the atom...
waste has been discharged into the Irish Sea as part of operations at Sellafield since 1952. The rate of discharge began to accelerate in the mid- to late 1960s, reaching a peak in the 1970s and generally declining significantly since then. As an example of this profile, discharges of plutonium
Plutonium
Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...
(specifically 241Pu) peaked in 1973 at 2,755TBq
Becquerel
The becquerel is the SI-derived unit of radioactivity. One Bq is defined as the activity of a quantity of radioactive material in which one nucleus decays per second. The Bq unit is therefore equivalent to an inverse second, s−1...
falling to 8.1 TBq by 2004. Improvements in the treatment of waste in 1985 and 1994 resulted in further reductions in radioactive waste discharge although the subsequent processing of a backlog resulted in increased discharges of certain types of radioactive waste. Discharges of technetium
Technetium
Technetium is the chemical element with atomic number 43 and symbol Tc. It is the lowest atomic number element without any stable isotopes; every form of it is radioactive. Nearly all technetium is produced synthetically and only minute amounts are found in nature...
in particular rose from 6.1 TBq in 1993 to a peak of 192TBq in 1995 before dropping back to 14TBq in 2004. In total 22PBq of 241Pu was discharged over the period 1952 to 1998. Current rates of discharge for many radionuclides are at least 100 times lower than they were in the 1970s.
Analysis of the distribution of radioactive contamination after discharge reveals that mean sea currents result in much of the more soluble elements such as caesium
Caesium
Caesium or cesium is the chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-gold alkali metal with a melting point of 28 °C , which makes it one of only five elemental metals that are liquid at room temperature...
being flushed out of the Irish Sea through the North Channel about a year after discharge. Measurements of technetium concentrations post-1994 has produced estimated transit times to the North Channel of around six months with peak concentrations off the northeast Irish coast occurring 18–24 months after peak discharge. Less soluble elements such as plutonium are subject to much slower redistribution. Whilst concentrations have declined in line with the reduction in discharges they are markedly higher in the eastern Irish Sea compared to the western areas. The dispersal of these elements is closely associated with sediment activity, with mud
Mud
Mud is a mixture of water and some combination of soil, silt, and clay. Ancient mud deposits harden over geological time to form sedimentary rock such as shale or mudstone . When geological deposits of mud are formed in estuaries the resultant layers are termed bay muds...
dy deposits on the seabed acting as sinks, soaking up an estimated 200kg of plutonium
Plutonium
Plutonium is a transuranic radioactive chemical element with the chemical symbol Pu and atomic number 94. It is an actinide metal of silvery-gray appearance that tarnishes when exposed to air, forming a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation...
. The highest concentration is found in the eastern Irish Sea in sediment banks lying parallel to the Cumbrian coast. This area acts as a significant source of wider contamination as radionuclides are dissolved once again. Studies have revealed that 80% of current sea water contamination by caesium is sourced from sediment banks, whilst plutonium levels in the western sediment banks between the Isle of Man and the Irish coast are being maintained by contamination redistributed from the eastern sediment banks.
The consumption of seafood
Seafood
Seafood is any form of marine life regarded as food by humans. Seafoods include fish, molluscs , crustaceans , echinoderms . Edible sea plants, such as some seaweeds and microalgae, are also seafood, and are widely eaten around the world, especially in Asia...
harvested from the Irish Sea is the main pathway for exposure of human
Human
Humans are the only living species in the Homo genus...
s to radioactivity. The environmental monitoring report for the period 2003 to 2005 published by the Radiological Protection Institute of Ireland
Radiological Protection Institute of Ireland
The Radiological Protection Institute of Ireland is an independent public body in the Republic of Ireland under the ageis of the Department of Environment, Heritage and Local Government.The RPII was established in 1992 under the , which conferred on the RPII a broad remit in relation to...
(RPII) reported that in 2005 average quantities of radioactive contamination found in seafood ranged from less than 1Bq/kg for fish to under 44Bq/kg for mussels. Doses of man-made radioactivity received by the heaviest consumers of seafood in Ireland in 2005 was 1.10µSv
Sievert
The sievert is the International System of Units SI derived unit of dose equivalent radiation. It attempts to quantitatively evaluate the biological effects of ionizing radiation as opposed to just the absorbed dose of radiation energy, which is measured in gray...
. This compares with a corresponding dosage of radioactivity naturally occurring in the seafood consumed by this group of 148µSv and a total average dosage in Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
from all sources of 3620µSv. In terms of risk to this group, heavy consumption of seafood generates a 1 in 18 million chance of causing cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
. The general risk of contracting cancer in Ireland is 1 in 522. In the UK, the heaviest seafood consumers in Cumbria received a radioactive dosage attributable to Sellafield discharges of 0.22mSv (220µSv) in 2005. This compares to average annual dose of naturally sourced radiation received in the UK of 2.23mSv (2230µSv).
Also see Beaufort's Dyke
Beaufort's Dyke
Beaufort's Dyke is the sea trench between Northern Ireland and Scotland within the North Channel. The dyke is 50 km long, 3.5 km wide and 200–300 metres deep....
.
East Irish Sea Basin
With 7.5 trillion cubic feet (210 km³) of natural gasNatural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...
and 176 million barrels (28,000,000 m³) of petroleum
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
estimated by the field operators as initially recoverable hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
reserves from eight producing fields (DTI, 2001), the East Irish Sea Basin is at a mature exploration phase. Early Namurian
Silesian (age)
The Silesian is in the geologic timescale of Europe a series or epoch, a subdivision of the Carboniferous system or period. It follows or lies on top of the Dinantian epoch/series and lasted from roughly 326.4 to 299.0 Ma ago. The Silesian is subdivided into three stages: Stephanian, Westphalian...
basinal mudstone
Mudstone
Mudstone is a fine grained sedimentary rock whose original constituents were clays or muds. Grain size is up to 0.0625 mm with individual grains too small to be distinguished without a microscope. With increased pressure over time the platey clay minerals may become aligned, with the...
s are the source rocks for these hydrocarbons. Production from all fields is from fault-bounded traps of the Lower Triassic
Triassic
The Triassic is a geologic period and system that extends from about 250 to 200 Mya . As the first period of the Mesozoic Era, the Triassic follows the Permian and is followed by the Jurassic. Both the start and end of the Triassic are marked by major extinction events...
formation, principally the aeolian Sherwood Sandstone reservoir, top-sealed by younger Triassic continental mudstones and evaporite
Evaporite
Evaporite is a name for a water-soluble mineral sediment that result from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporate deposits, marine which can also be described as ocean deposits, and non-marine which are found in standing bodies of...
s. Future mineral exploration
Mineral exploration
Mineral exploration is the process of finding ore to mine. Mineral exploration is a much more intensive, organized and professional form of mineral prospecting and, though it frequently uses the services of prospecting, the process of mineral exploration on the whole is much more involved.-Stages...
will initially concentrate on extending this play, but there remains largely untested potential also for gas and oil within widespread Carboniferous
Carboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...
fluvial
Fluvial
Fluvial is used in geography and Earth science to refer to the processes associated with rivers and streams and the deposits and landforms created by them...
sandstone
Sandstone
Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...
reservoirs. This play requires intraformational mudstone seal units to be present, as there is no top-seal for reservoirs subcropping the regional base Permian
Permian
The PermianThe term "Permian" was introduced into geology in 1841 by Sir Sir R. I. Murchison, president of the Geological Society of London, who identified typical strata in extensive Russian explorations undertaken with Edouard de Verneuil; Murchison asserted in 1841 that he named his "Permian...
unconformity
Unconformity
An unconformity is a buried erosion surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger, but the term is used to describe...
in the east of the basin, and Carboniferous strata
Stratum
In geology and related fields, a stratum is a layer of sedimentary rock or soil with internally consistent characteristics that distinguish it from other layers...
crop out at the sea bed in the west.
Caernarfon Bay Basin
The Caernarfon BayCaernarfon Bay
Caernarfon Bay is an inlet of the Irish Sea defined by the Llŷn peninsula and Anglesey.The gentle coastline surrounding it is home to villages including Nefyn, Trefor, and Clynnog Fawr on the mainland, and Aberffraw, Llanddwyn and Rhosneigr on Anglesey.The Menai Strait heads north east to link the...
basin contains up to 7 km³ of Permian and Triassic syn-rift sediments in an asymmetrical graben
Graben
In geology, a graben is a depressed block of land bordered by parallel faults. Graben is German for ditch. Graben is used for both the singular and plural....
that is bounded to the north
North
North is a noun, adjective, or adverb indicating direction or geography.North is one of the four cardinal directions or compass points. It is the opposite of south and is perpendicular to east and west.By convention, the top side of a map is north....
and south
South
South is a noun, adjective, or adverb indicating direction or geography.South is one of the four cardinal directions or compass points. It is the opposite of north and is perpendicular to east and west.By convention, the bottom side of a map is south....
by Lower Paleozoic
Paleozoic
The Paleozoic era is the earliest of three geologic eras of the Phanerozoic eon, spanning from roughly...
massif
Massif
In geology, a massif is a section of a planet's crust that is demarcated by faults or flexures. In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole...
s. Only two exploration wells have been drilled so far, and there remain numerous undrilled targets in tilted fault block plays. As in the East Irish Sea Basin, the principal target reservoir is the Lower Triassic, Sherwood Sandstone, top-sealed by younger Triassic mudstones and evaporites. Wells in the Irish Sector to the west have demonstrated that pre-rift, Westphalian
Westphalian (stage)
The Westphalian is a stage in the regional stratigraphy of northwest Europe with an age between roughly 313 and 304 Ma . It is a subdivision of the Carboniferous system or period and the regional Silesian series. The Westphalian is named for the region of Westphalia in western Germany where strata...
coal measures are excellent hydrocarbon source rocks, and are at peak maturity for gas generation (Maddox et al., 1995). Seismic profiles
Seismogram
A seismogram is a graph output by a seismograph. It is a record of the ground motion at a measuring station as a function of time. Seismograms typically record motions in three cartesian axes , with the z axis perpendicular to the Earth's surface and the x- and y- axes parallel to the surface...
clearly image these strata continuing beneath a basal Permian unconformity into at least the western part of the Caernarfon Bay Basin. The timing of gas generation presents the greatest exploration risk. Maximum burial of, and primary gas migration from, the source rocks could have terminated as early as the Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
, whereas many of the tilted fault blocks were reactivated or created during Paleogene
Paleogene
The Paleogene is a geologic period and system that began 65.5 ± 0.3 and ended 23.03 ± 0.05 million years ago and comprises the first part of the Cenozoic Era...
inversion of the basin. However, it is also possible that a secondary gas charge occurred during regional heating associated with intrusion of Paleogene dykes, such as those that crop out nearby on the coastline of north Wales. (Floodpage et al., 1999) have invoked this second phase of Paleogene hydrocarbon generation as an important factor in the charging of the East Irish Sea Basin's oil and gas fields. It is not clear as yet whether aeromagnetic anomalies in the southeast of Caernarfon Bay are imaging a continuation of the dyke swarm into this area too, or whether they are instead associated with deeply buried Permian syn-rift volcanics. Alternatively, the fault block traps could have been recharged by exsolution of methane
Methane
Methane is a chemical compound with the chemical formula . It is the simplest alkane, the principal component of natural gas, and probably the most abundant organic compound on earth. The relative abundance of methane makes it an attractive fuel...
from formation brine
Brine
Brine is water, saturated or nearly saturated with salt .Brine is used to preserve vegetables, fruit, fish, and meat, in a process known as brining . Brine is also commonly used to age Halloumi and Feta cheeses, or for pickling foodstuffs, as a means of preserving them...
s as a direct result of the Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
uplift (cf. Doré and Jensen, 1996).
The Cardigan Bay Basin
The Cardigan BayCardigan Bay
Cardigan Bay is a large inlet of the Irish Sea, indenting the west coast of Wales between Bardsey Island, Gwynedd in the north, and Strumble Head, Pembrokeshire at its southern end. It is the largest bay in Wales....
Basin forms a continuation into British waters of Ireland's North Celtic Sea Basin, which has two producing gas fields. The basin comprises a south-easterly deepening half-graben near the Welsh coastline, although its internal structure becomes increasingly complex towards the southwest. Permian to Triassic, syn-rift sediments within the basin are less than 3 km thick and are overlain by up to 4 km of Jurassic strata, and locally also by up to 2 km of Paleogene fluvio-deltaic sediments. The basin has a proven petroleum system, with potentially producible gas reserves at the Dragon discovery near the UK/ROI median line, and oil shows in a further three wells. The Cardigan Bay Basin contains multiple reservoir targets, which include the Lower Triassic (Sherwood Sandstone), Middle Jurassic
Middle Jurassic
The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from 176-161 million years ago. In European lithostratigraphy, rocks of this Middle Jurassic age are called the Dogger....
shallow marine sandstones and limestone (Great Oolite
Oolite
Oolite is a sedimentary rock formed from ooids, spherical grains composed of concentric layers. The name derives from the Hellenic word òoion for egg. Strictly, oolites consist of ooids of diameter 0.25–2 mm; rocks composed of ooids larger than 2 mm are called pisolites...
), and Upper Jurassic fluvial sandstone, the reservoir for the Dragon discovery. The most likely hydrocarbon source rocks are Early Jurassic
Early Jurassic
The Early Jurassic epoch is the earliest of three epochs of the Jurassic period...
marine mudstones. These are fully mature for oil generation in the west of the British sector, and are mature for gas generation nearby in the Irish sector. Gas-prone, Westphalian pre-rift coal measures may also be present at depth locally. The Cardigan Bay Basin was subjected to two Tertiary phases of compressive uplift, whereas maximum burial that terminated primary hydrocarbon generation was probably around the end of the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
, or earlier if Cretaceous strata, now missing, were never deposited in the basin. Despite the Tertiary structuration, the Dragon discovery has proved that potentially commercial volumes of hydrocarbons were retained at least locally in Cardigan Bay. In addition to undrilled structural traps, the basin contains untested potential for stratigraphic entrapment of hydrocarbons near synsedimentary faults, especially in the Middle Jurassic section.
Liverpool Bay
The Liverpool Bay Development is BHP Billiton Petroleum's largest operated asset. It comprises the integrated development of five offshore oil and gas fields in the Irish Sea:- Douglas oil field
- Hamilton gas field
- Hamilton North gas field
- Hamilton East gas field
- Lennox oil and gas field
Oil is produced from the Lennox and Douglas fields. It is then treated at the Douglas Complex and piped 17 kilometres to an oil storage barge ready for export by tankers. Gas is produced from the Hamilton, Hamilton North and Hamilton East reservoirs. After initial processing at the Douglas Complex
Douglas Complex
The Douglas Complex is a high system of three linked platforms in the Irish Sea, off the North Wales coast. The Douglas oil field was discovered in 1990, and production commenced in 1996...
the gas is piped by subsea pipeline to the Point of Ayr
Point of Ayr
Point of Ayr is the northernmost point of mainland Wales. It is situated immediately to the north of Talacre in Flintshire, at the mouth of the Dee estuary. It is to the southwest of the Liverpool Bay area of the Irish Sea...
gas terminal for further processing. The gas is then sent by onshore pipeline to PowerGen's combined cycle gas turbine power station
Power station
A power station is an industrial facility for the generation of electric energy....
at Connah's Quay
Connah's Quay
Connah's Quay is the largest town in Flintshire, North Wales, lying on the River Dee, near the border with England. It can be accessed by road from the A550, by rail from the nearby Shotton station and also lies on the National Cycle Network Route 5. It is situated near the region's industrial...
. PowerGen is the sole purchaser of gas from the Liverpool Bay development.
The Liverpool Bay development comprises four offshore platforms. Offshore storage and loading facilities. The onshore gas processing terminal at Point of Ayr.
Production first started at each filed as follows: Hamilton North in 1995, Hamilton in 1996, Douglas in 1996, Lennox (oil only) in 1996 and Hamilton East 2001. The first contract gas sales were in 1996.
Liverpool Bay has been historically contaminated by discharges of sewage sludge, compromising water quality for this part of the Irish Sea.
Dalkey Island Exploration Prospect
Previous exploration drilling in the Kish Bank Basin has confirmed the potential for petroleum generation with oil shows seen in a number of wells together with natural hydrocarbon seeps recorded from airborne surveys. New analysis of vintage 2-D seismic data has revealed the presence of a large undrilled structural closure at Lower Triassic level situated c. 10 km offshore Dublin. This feature, known as the Dalkey Island exploration prospect, may be prospective for oil, as there are prolific oil productive Lower Triassic reservoirs nearby in the eastern Irish Sea offshore Liverpool. Whilst the Dalkey Island exploration prospect could contain c. 870 MMBO in place, this undrilled prospect still has significant risk and the partners are currently advancing a focused work programme in order to better understand and hopefully mitigate these risks. However, given its location in shallow water and close proximity to shore, the prospect is of great interest as exploration drilling, together with any future development costs, are likely to be low.Proposed tunnel projects
Discussions of linking Britain to Ireland began in 1895, with an application for £15,000 towards the cost of carrying out borings and soundings in the North Channel to see if a tunnel between Ireland and Scotland was viable. Sixty years later Harford Montgomery HydeHarford Hyde
Harford Montgomery Hyde , born in Belfast, was a barrister, politician , author and biographer, who lost his seat in the House of Commons of the United Kingdom as a result of campaigning for homosexual law reform.-Background:Born on 14 August 1907, on the Malone Road in Belfast, Hyde was schooled...
, Unionist MP for North Belfast, called for the building of such a tunnel. A tunnel project has been discussed several times in the Irish parliament
Dáil Éireann
Dáil Éireann is the lower house, but principal chamber, of the Oireachtas , which also includes the President of Ireland and Seanad Éireann . It is directly elected at least once in every five years under the system of proportional representation by means of the single transferable vote...
. The idea for such a 34 km (21 mi) long rail
Rail transport
Rail transport is a means of conveyance of passengers and goods by way of wheeled vehicles running on rail tracks. In contrast to road transport, where vehicles merely run on a prepared surface, rail vehicles are also directionally guided by the tracks they run on...
bridge
Bridge
A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle...
or tunnel
Tunnel
A tunnel is an underground passageway, completely enclosed except for openings for egress, commonly at each end.A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. Some tunnels are aqueducts to supply water for consumption or for hydroelectric stations or are sewers...
, continues to be mooted.
Several potential Irish Sea tunnel projects have been proposed, most recently the "Tusker Tunnel
Tusker Tunnel
The Tusker Tunnel is an idea for an Irish Sea tunnel project aimed at linking the ports of Rosslare and Fishguard located in Ireland and Wales respectively. The idea was first mentioned by the Institute of Engineers of Ireland in 2004...
" between the ports of Rosslare and Fishguard proposed by The Institute of Engineers of Ireland in 2004. A different proposed route between Dublin and Holyhead was proposed in 1997 by the British engineering firm Symonds. Either tunnel, at 80 kilometres (49.7 mi), would be by far the longest in the world, and would cost an estimated €20 billion.
Wind power
An offshore wind farm was developed on the Arklow
Arklow
Arklow , also known as Inbhear Dé from the Avonmore river's older name Abhainn Dé, is a historic town located in County Wicklow on the east coast of Ireland. Founded by the Vikings in the ninth century, Arklow was the site of one of the bloodiest battles of the 1798 rebellion...
Bank, Arklow Bank Wind Park
Arklow Bank Wind Park
The Arklow Bank Wind Park is the first offshore wind farm in Ireland and the world's first commercial application of offshore wind turbines over 3 megawatts in size. It is located on the Arklow Bank, a shallow water sandbank in the Irish Sea, around off the coast of Arklow with an area of...
, about 10 km off the coast of County Wicklow
County Wicklow
County Wicklow is a county in Ireland. It is part of the Mid-East Region and is also located in the province of Leinster. It is named after the town of Wicklow, which derives from the Old Norse name Víkingalág or Wykynlo. Wicklow County Council is the local authority for the county...
in the south Irish Sea. The site currently has seven GE 3.6 MW turbine
Wind turbine
A wind turbine is a device that converts kinetic energy from the wind into mechanical energy. If the mechanical energy is used to produce electricity, the device may be called a wind generator or wind charger. If the mechanical energy is used to drive machinery, such as for grinding grain or...
s, each with 104 m diameter rotor
Turbine
A turbine is a rotary engine that extracts energy from a fluid flow and converts it into useful work.The simplest turbines have one moving part, a rotor assembly, which is a shaft or drum with blades attached. Moving fluid acts on the blades, or the blades react to the flow, so that they move and...
s, the world's first commercial application of offshore wind turbines over three megawatts in size. The operating company, Airtricity
Airtricity
Airtricity was founded in 1997 in the Republic of Ireland and now is a renewable energy company owned by Scottish and Southern Energy...
, has indefinite plans for nearly 100 further turbines on the site.
Further wind turbine sites include:
- The North HoyleNorth HoyleNorth Hoyle Offshore Wind Farm is Wales' first offshore wind farm, and the UK's first major offshore renewable power project. Situated in Liverpool Bay, it commenced operation in 2003....
site 5 miles (8 km) off the coast from RhylRhylRhyl is a seaside resort town and community situated on the north east coast of Wales, in the county of Denbighshire , at the mouth of the River Clwyd . To the west is the suburb of Kinmel Bay, with the resort of Towyn further west, Prestatyn to the east and Rhuddlan to the south...
and PrestatynPrestatynPrestatyn is a seaside resort, town and community in Denbighshire, North Wales. It is located on the Irish Sea coast, to the east of Rhyl. At the 2001 Census, Prestatyn had a population of 18,496.-Prehistory:...
in North WalesNorth WalesNorth Wales is the northernmost unofficial region of Wales. It is bordered to the south by the counties of Ceredigion and Powys in Mid Wales and to the east by the counties of Shropshire in the West Midlands and Cheshire in North West England...
, containing thirty 2 MW turbines. operated by NPower RenewablesNpower (UK)RWE Npower plc is a UK-based electricity and gas supply generation company, formerly known as Innogy plc. As Innogy plc it was listed on the London Stock Exchange and was a constituent of the FTSE 100 Index... - Burbo BankBurbo Bank Offshore Wind FarmThe Burbo Bank Offshore Wind Farm is a wind farm located on the Burbo Flats in Liverpool Bay at the entrance to the River Mersey. It is owned and operated by DONG Energy. The wind farm consists of 25 Siemens Wind Power 3.6MW wind turbines with a total nameplate capacity of 90 megawatts...
site 10 km off the north WirralWirral PeninsulaWirral or the Wirral is a peninsula in North West England. It is bounded by three bodies of water: to the west by the River Dee, forming a boundary with Wales, to the east by the River Mersey and to the north by the Irish Sea. Both terms "Wirral" and "the Wirral" are used locally , although the...
coast - Robin Rigg Wind FarmRobin Rigg Wind FarmRobin Rigg Wind Farm, Scotland's first offshore wind farm, has been constructed by E.ON at Robin Rigg in the Solway Firth, a sandbank midway between the Galloway and Cumbrian coasts. The windfarm first generated power for test purposes on 9 September 2009...
in the Solway Firth - Thirty 90 m 3 MW turbines are operating in a wind farm 7 km off the coast of Walney IslandWalney IslandThe Isle of Walney, also known as Walney Island, is an island in the United Kingdom which lies off the west coast of England, at the northern tip of Morecambe Bay. It forms part of the Borough of Barrow-in-Furness, and it is separated from the mainland at Barrow by Walney Channel, a narrow channel...
. - Turbines are being erected off the coast of ClogherheadClogherheadClogherhead is a fishing village in County Louth, Ireland. Located in a picturesque natural bay on the East Coast it is bordered by the villages of Annagassan to the north and Termonfeckin to the south. with an administrative population per the 2011 Census of 3026, it is in the townlands of...
(to be called the Oriel Wind FarmOriel Wind FarmOriel Windfarm is a privately owned Irish sustainable and renewable energy company. It was established in order to develop wind farms in Ireland and the company’s first project is the development of an offshore wind farm in the northwest Irish Sea....
)