With an area of 148 square miles (383 km2), it is the British Isles' largest lake by area and is ranked 34th in thelist of largest lakes of Europe.[citation needed] Located 20 miles (32 km) west ofBelfast, it is about 19 miles (31 km) long and 9 miles (14 km) wide. It is very shallow around the margins and the average depth in the main body of the lake is about 30 feet (9 m), although at its deepest the lough is about 80 feet (24 m) deep.
Geologically the Lough Neagh Basin is a depression, built from many tectonic events dating back as far as 400 million years ago. These tectonic events are responsible for a NE-SW bedrock structure which has controlled many subsequent events. During the Paleozoic era, the Lough Neagh Basin was a depositionalgraben.[10]
Of the 1,760-square-mile (4,550 km2) catchment area, around 9% lies in theRepublic of Ireland and 91% in Northern Ireland;[11] altogether 43% of the land area of Northern Ireland is drained into the lough,[12] which itself flows out northwards to the sea via theRiver Bann. As one of its sources is the Upper Bann, the Lough can itself be considered as part of the Bann.Lough Neagh is fed by many tributaries including the riversMain (34 mi, 55 km),Six Mile Water (21 mi, 34 km),Upper Bann (40 mi, 64 km),Blackwater (57 mi, 92 km),Ballinderry (29 mi, 47 km) andMoyola (31 mi, 50 km)[13]
The water in the lough has been monitored extensively since 1974 and has undergone considerable eutrophication and toxic algal blooms. According to a 2016 study, it "has become much enriched as a result of anthropogeniceutrophication, most of which occurred in the last century... Despite the recent changes in nutrient loading the lake is still currently classed as hypereutrophic".[14] In 2023 and 2024, toxicalgal blooms, mostly caused byagricultural run-off, spread across the lake.[15][16][17][18]
Five of the sixcounties of Northern Ireland have shores on the Lough (onlyFermanagh does not), and its area is split among them. The counties are listed clockwise:
Antrim (eastern side and northern shore of the lake)
Lough Neagh is managed by Lough Neagh Partnership Ltd, a stakeholder group made up of elected representatives, land-owners, fishermen, sand traders and local community representatives. Lough Neagh Partnership is responsible for the lough's conservation, promotion and sustainable development together with navigation of the Lough.[20]
Although the Lough is used for a variety of recreational and commercial activities, it is exposed and tends to get extremely rough very quickly in windy conditions.[21]
According toNorthern Ireland Water, Lough Neagh supplies 40.7% of Northern Ireland's drinking water.[22] There have long been plans to increase the amount of water drawn from the lough, through a newwater treatment works at Hog Park Point, but these are yet to materialise. The lough's ownership bythe 12th Earl of Shaftesbury has implications for planned changes to state-run domestic water services in Northern Ireland,[23] as the lough is also used as asewage outfall, and this arrangement is only permissible throughCrown immunity.[citation needed]
Traditional working boats on Lough Neagh include wide-beamed 4.9-to-6.4-metre (16 to 21 ft)clinker-built,sprit-rigged working boats and smaller flat-bottomed "cots" and "flats". Barges, here called "lighters", were used until the 1940s to transport coal over the lough and adjacent canals. Until the 17th century, log boats (coití) were the main means of transport. Few traditional boats are left now, but a community-based group on the southern shore of the lough is rebuilding a series of working boats.[24]
In the 19th century, threecanals were constructed, using the lough to link various ports and cities: theLagan Navigation provided a link from the city ofBelfast, theNewry Canal linked to the port ofNewry, and theUlster Canal led to theLough Erne navigations, providing a navigable inland route via theRiver Shannon toLimerick, Dublin andWaterford. The Lower Bann was also navigable toColeraine and the Antrim coast, and the shortCoalisland Canal provided a route for coal transportation. Of these waterways, only the Lower Bann remains open today, although a restoration plan for the Ulster Canal is currently in progress.
Lough Neagh Rescue provides a search and rescue service 24 hours a day and has 3 stations, situated around the lough. These are at Antrim, Ardboe and Kinnego Marinas, Kinnego being its headquarters and founding station. It is a voluntary service funded by the district councils bordering the Lough. Its members are highly trained and are a declared facility for theMaritime and Coastguard Agency which co-ordinates rescues on Lough Neagh.
Lough Neagh attractsbirdwatchers from many nations due to the number and variety of birds which winter and summer in theboglands and shores around the lough.
Eel fishing has been a major industry in Lough Neagh for centuries. TheseEuropean eels make their way from theSargasso Sea in the Atlantic Ocean, some 4,000 miles (6,000 km) along theGulf Stream to the mouth of theRiver Bann, and then make their way into the lough. They remain there for some 10 to 15 years, maturing, before returning to the Sargasso to spawn. Today Lough Neagh eel fisheries export their eels to restaurants all over the world, and the Lough Neagh Eel has been grantedProtected Geographical Status underEuropean Union law.[26]
Nobel laureateSeamus Heaney produced a collection of poemsA Lough Neagh Sequence celebrating the eel-fishermen's traditional techniques and the natural history of their catch.[27]
Other fish species in the lake includedollaghan —a variety of brown trout native to the lake, salmon, trout, perch andpollan; bream,gudgeon, pike andrudd are also found, but are less common.[28]
The lough's English name derives fromIrishLoch nEachach, meaning 'Eachaidh's lake'.[9] At the start of thePlantation of Ulster, the English attempted to rename the lake 'LoughSydney' and 'LoughChichester', in honour of theLord Deputies, but these did not supplant the older name.[29]
In theIrish mythical taleCath Maige Tuired ("the Battle of Moytura"), Lough Neagh is called one of the twelve chief loughs of Ireland.[30] The origin of the lake and its name is explained in an Irish tale that was written down in theMiddle Ages, but is likely pre-Christian.[31][32] According to the tale, the lake is named after Echaid (modern spelling: Eochaidh or Eachaidh), who was the son of Mairid (Mairidh), a king ofMunster. Echaid falls in love with his stepmother, a young woman named Ébliu (Ébhlinne). They try to elope, accompanied by many of their retainers, but someone kills their horses.[31][32]
In some versions, the horses are killed byMidir (Midhir), which may be another name for Ébliu's husband Mairid.Óengus (Aonghus) then appears and gives them an enormous horse that can carry all their belongings. Óengus warns that they must not let the horse rest or it will be their doom.[31][32]
After reaching Ulster the horse stops and urinates, and a spring rises from the spot. Echaid builds a house there and covers the spring with a capstone to stop its overflowing. One night, the capstone is not replaced and the spring overflows, drowning Echaid and most of his family, and creatingLoch n-Echach (Loch nEachach, the lake of Eachaidh).[31][32]
The character Echaid refers tothe Dagda, a god of the ancient Irish who was also known as Echaid Ollathair (meaning "horseman, father of all").[32] Ébliu, Midir and Óengus were also names of deities.Dáithí Ó hÓgáin writes that the idea of a supernatural being creating the landscape with its own body is an ancient one common to many pre-Christian cultures.[32] AGaelicsept called theUí Echach ("descendants of Echaid") dwelt in the area and it is likely their name comes from the cult of the god.[31] They gave their name to the territory ofIveagh.
Another tale tells how the lake was formed when Ireland's legendary giantFionn mac Cumhaill (Finn McCool) scooped up a chunk of earth and tossed it at a Scottish rival. It fell into theIrish Sea, forming theIsle of Man, while the crater left behind filled with water to form Lough Neagh.[33]
During the early seventeenth century,Sir Arthur Chichester, later created the 1stBaron Chichester, gradually laid claim to Lough Neagh during the Stuart conquest ofUlster, taking advantage of theFlight of the Earls. He first laid claim to the lough's infrastructure, then to its boats, then the shores and finally the lough in its entirety, including all relevant fishing rights. It is possible he did this without approval fromJames VI and I. The lough was later inherited byEdward, 1st Viscount Chichester, Sir Arthur's younger brother; Edward's descendants later married into the Shaftesbury family.[37] In 2012, it was reported thatthe 12th Earl of Shaftesbury was considering transferring ownership of the lough to theNorthern Ireland Assembly.[38]
In October 2023, Lord Shaftesbury stated in an interview withBBC Northern Ireland that while he was open to selling Lough Neagh to the Northern Irish public, he would not give it away for free. He stated in the interview that "the sale is one that's borne out of an understanding that my ownership has always been very divisive and quite political and I always get blamed for things that are completely outside of my control. I feel it's often used as an excuse for political inaction and I always want to do the right thing by the people living here and what's in the best interest of the lough."[39]
In February 2024 concerns were raised at the sudden collapse in insect numbers on the Lough and the likely effects this will have on biodiversity in the area.[40]
Lough Neagh underwent catastrophiccyanobacteria or blue green algae bloom events in the summer of 2023 and 2024 which reached international news channels.[41][42][43] This has led to numerous local community and environmental organization responses, such as a mockwake for the lake being held in protest and calls for drastic action to solve the problem.[44][45][46] The size of these algal blooms in Lough Neagh has allowed them to be visible from space.These algal blooms have the potential to have significant impacts on the lakes ecology due to the toxins they produce posing a serious risk to wildlife, including birds and fish, risking declines in populations and disrupting the food web.[47] In addition, the growth of the algal blooms depletes oxygen in the water which can cause fish kills.[47] There are also threats to human health from toxins and pathogens detected in the algal mats found in the lake.[47]
These harmful algal blooms have a number factors contributing to their occurrence in Lough Neagh. The foremost contributory factor is the eutrophication of the lake with nutrients like phosphorus and nitrates which have provided suitable conditions for the algae to thrive.[48] The lake has been classified as one of the world's most hyper-eutrophic water-bodies due to chronic eutrophication occurring over many years.[49][50] Key drivers of this eutrophication are increases in nitrates and phosphates in the lake which are generally attributed to runoff from agriculture in the form of animal slurry residue of chemical fertilizer in addition to human sewage.[51] Research has indicated that 62% of the phosphorus inputs are from agricultural origins, 24% are from wastewater treatment works and 12% are from septic tanks.[52]
A number of other environmental factors have contributed to the occurrence of the harmful algal blooms. Climate change has contributed to increasing summer temperatures of, and sunlight intensity on, the lake, creating more suitable conditions for rapid growth of harmful algal blooms. As the lake is relatively shallow with an average depth of 9m, its temperature can increase more rapidly than other deeper lakes, making it more susceptible to algal blooms.[53]
The invasivezebra mussel mollusc species which has invaded the lake has resulted in the lake water having greater clarity and so penetration of light. The increase in light intensity deeper in the water column has increased the chance of harmful algal blooms occurring. The zebra mussel which is a filter feeder on phytoplankton in the lake, will selectively feed on existing phytoplankton species but not on the blue green algae, creating a lower ecological competition scenario for these algae.[53]
When the algal bloom crisis of 2023 occurred, theNorthern Ireland Assembly was suspended and Northern Ireland had no functioningdevolved government. TheSocial Democratic and Labour Party MLAMatthew O'Toole referred to the state of the lough as "a metaphor for the poisoned state of politics and governance in the North". After the Assembly and Executive were restored in February 2024, all major parties agreed that action was required to address the crisis, and by July 2024 an action plan proposed by the Minister of Agriculture, Environment and Rural Affairs, theAlliance Party'sAndrew Muir had been agreed,[43][54] although some aspects of the plan had to be scaled back due to resistance from theDemocratic Unionist Party.[43]
Some environmental activists have argued that the lough needs to be brought into community ownership and granted rights, inspired by the globalrights of nature movement.[43][55][56]
^abHackney, P. 1992.Stewart & Corry's Flora of the North-east of Ireland. Third Edition. The Institute of Irish Studies, The Queen's University of Belfast.ISBN0 85389 446 9
^Roesdahl, Else (2016).The Vikings (Third ed.). Penguin Books. p. 232.ISBN978-0-141-98476-6.
^abFalkiner, Caesar Litton; Ball, Francis Elrington, eds. (1904)."Draft of a Letter relating to the Captain of Lough Neagh".Calendar of the manuscripts of the Marquess of Ormonde, K. P., preserved at Kilkenny castle; N.S. Vol. III.Command papers. Vol. Cd.1963. London: HMSO. pp. 246–248. Retrieved21 June 2019.
^P. (17 April 1841). Hall, S. C.; Carleton, William; Doyle, Martin; Petrie, George (eds.)."Antrim Castle".The Irish Penny Journal. Dublin: James Duffy:329–330.
^Cave, S., Allen, M., & Research and Information Service. (2023). An overview of algal bloom in Lough Neagh. InNIAR 138-23 Briefing Paper (pp. 1–4) [Report]. https://www.niassembly.gov.uk/globalassets/documents/raise/publications/2022-2027/2024/aera/0624.pdf
^abThe Lough Neagh Report: Blue Green algae and water quality in Northern Ireland. (2024). InThe Lough Neagh Report. https://www.daera-ni.gov.uk/sites/default/files/publications/daera/Lough%20Neagh%20Report%20and%20Action%20Plan.pdf
Wood, R.B.; Smith, R.V., eds. (1993).Lough Neagh: The Ecology of a Multipurpose Water Resource. Monographiae Biologicae. Vol. 69. Springer.ISBN978-0-7923-2112-5.