
Strangford Lough is a large sealough orinlet inCounty Down, in the east ofNorthern Ireland. It is the largest inlet in Ireland and the widerBritish Isles, covering 150 km2 (58 sq mi). The lough is almost fully enclosed by theArds Peninsula and is linked to theIrish Sea by a long narrow channel at its southeastern edge. The main body of the lough has at least seventy islands along with many islets (pladdies), bays, coves, headlands and mudflats. It is part of the Strangford andLecaleArea of Outstanding Natural Beauty. Strangford Lough was designated as Northern Ireland's firstMarine Conservation Zone in 2013, and has been designated aSpecial Area of Conservation for its important wildlife.
Strangford Lough is a popular tourist destination noted for its fishing and scenery. Towns and villages around the lough includeKillyleagh,Comber,Newtownards,Portaferry andStrangford. The latter two straddle either shore of the narrow Strangford channel, and are connected by acar ferry.
The nameStrangford comes from the Old NorseStrangfjörthr, meaning "strongfjord" or rather "fjord of the strong current". Originally it referred to the channel linking the lough to the sea, between the villages ofStrangford andPortaferry, but it was extended to the lough as a whole from the 17th century onwards. The lough had previously been known asLough Cone orLough Coyne in English, from the IrishLoch Cuan ("lough of the harbours").[1]
The lough was formed at the end of thelast ice age and is generally under 10 metres (30 ft) deep, but can reach 50 to 60 metres (160 to 200 ft) in parts, generally the centre channel.[2]
Common cord-grass (Spartina anglica) C.E. Hubbard, introduced in the mid-1940s, is now abundant.[3]
Maerl is a calcareous deposit, in the main, of two species, ofcalcareousalgaePhymatolithon calcareum andLithothamnion glaciale which form free-living beds of unattached, branchedcorallines, living or dead, in Strangford Lough.[4]
The rocky and boulder shores toward the south of the lough are dominated by the seaweed knotted wrackAscophyllum nodosum. The usual zonation of weeds on these shore is, at the top channel wrack (Pelvetia canaliculata (L.) Dcne. et Rhur.), followed by spiral wrack (Fucus spiralis L.), then knotted wrack (Ascophyllum nodosum (L.) Le Jol) with some admixture of bladder wrack (Fucus vesiculosus) L. and then serrated wrack (Fucus serratus L.) before coming to the low water kelps.[5]
Other algae include:[6]
Strangford Lough and Islands is anImportant Bird Area.[7]Strangford Lough is an important wintermigration destination for many wading and seabirds.Animals commonly found in the lough includecommon seals,basking sharks andbrent geese. Three quarters of the world population of pale bellied brent geese spend winter in the lough area.[8] Often the numbers are up to 15,000.[9] TheCastle Espie wetland reserve sits on the banks of the lough nearComber.
The invasive carpet sea squirt,Didemnum vexillum, was found in the Lough in 2012.[10]

In 2007 Strangford Lough became home to the world's first commercialtidal stream power station,SeaGen. The 1.2megawatt underwater tidal electricity generator, part of Northern Ireland's Environment and Renewable Energy Fund scheme, took advantage of the fast tidal flow in the lough which can be up to 4m/s. Although the generator was powerful enough to power up to a thousand homes, theturbine had a minimalenvironmental impact, as it was almost entirely submerged, and the rotors turned slowly enough that they pose no danger towildlife.[11][12][13]
In 2008 atidal energy device calledEvopod was tested in Strangford Lough near the Portaferry Ferry landing.[14] The device was a 1/10 scale prototype, monitored byQueen's University Belfast. The device was a semi-submerged floating tidal turbine, moored to the seabed via a buoy-mounted swivel. The scale device was not grid connected.
In July 2016, the Strangford Lough and Lecale Partnership, Scottish Coastal Rowing Association,Newry, Mourne and Down District Council andArds and North Down Borough Council hosted the "Skiffie Worlds 2016" rowing championships. The event was attended by 50 clubs from Scotland, England, Northern Ireland, the Netherlands, The United States, Canada and Tasmania. Racing was held over a 2 km course on Strangford Lough atDelamont Country Park.[15]
ThePortaferry–Strangford ferry service has linkedPortaferry andStrangford, at the mouth of the Lough, without a break and for almost four centuries.[16] The alternative road journey is 47 miles (76 km) and takes about an hour and a half, while the ferry crosses the 0.6-nautical-mile (0.69 mi; 1.1 km) strait in 8 minutes.[17] The subsidised public service carries both passengers and vehicles, and operates at a loss of more than £1m per year but is viewed as an important transport link to the Ards Peninsula.[18]