Strangford Lough
The tide pouring through the mouth of Strangford Lough once drove the world's first commercial-scale tidal turbine, and a Viking name still describes the water: 'strong fjord'.
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Quick Facts
- Location
- County Down, Northern Ireland, between the Ards Peninsula and the mainland
- Size
- Roughly 150 square kilometres, the largest sea inlet in the British Isles
- Length
- About 30 km from the Narrows to Newtownards
- The Narrows
- About half a kilometre wide between Strangford and Portaferry, with fast tidal streams
- Islands
- More than 70, mostly drumlins drowned by rising seas
- Name
- From Old Norse, usually read as 'strong sea inlet'; the Irish name is Loch Cuan
- Tidal power
- SeaGen turbine (1.2 MW) installed 2008, generating until 2016, removal completed 2019
- Wildlife
- Winter home of thousands of light-bellied Brent geese, plus a breeding colony of common seals
The sea inlet that fills and empties twice a day
Strangford Lough is almost a landlocked sea. Its only link to the Irish Sea is a channel about half a kilometre wide, and every tide forces an enormous volume of water through it. The result is a race of water that churns, swirls and boils over the rocks. Local sailors treat the Narrows with respect, and the car ferry between Strangford and Portaferry has to cross at an angle to avoid being swept off course. The trip takes only about ten minutes, but you can feel the current pushing the boat. The Vikings noticed it too. The name Strangford comes from Old Norse and is generally taken to mean 'strong sea inlet'. Norse raiders and traders knew these waters well, and the name has outlasted them by a thousand years.
A drowned field of upturned eggs
The islands are the lough's signature. There are more than 70 of them, and they are mostly drumlins: smooth, oval hills of clay and gravel dumped by ice sheets at the end of the last Ice Age. County Down is full of these hills, often described as a basket of eggs. When the sea level rose, the water flooded the low ground and left the tops showing. The shores of the lough, the Ards Peninsula and the islands are all part of the same rolling drumlin landscape. Some of the little islands have names like Mid Island, Rock Angus and Pladdy Lug. Beneath the surface is another world. The lough's underwater habitats include reefs of horse mussels, as well as sea fans, sponges and anemones, which have made it one of the best-known marine sites in Ireland.
Geese, seals and a very busy winter
Winter is when the lough fills with wildfowl. Light-bellied Brent geese fly in from the Canadian Arctic to feed on the eelgrass of the mudflats, and Strangford hosts a large share of the entire population. Alongside them come wigeon, redshank, curlew and plenty of other waders. The lough is also a stronghold for common seals, which haul out on rocks and skerries at low tide. You can often spot them from the shore or on a boat trip, lying around like fat commas on the weed. The Wildfowl and Wetlands Trust centre at Castle Espie, near Comber, is one of the easiest places to watch the geese up close. Quieter spots along the Ards shore reward anyone with binoculars and a flask.
Saints, monks and the world's oldest tide mill
The lough's shores are crowded with history. Tradition says St Patrick came ashore at Saul, near the southern end, in the fifth century, and founded his first church in a barn given to him by a local chieftain. On Mahee Island stand the ruins of Nendrum, an early monastery. Excavations there uncovered the remains of a tide mill, which used the lough's rising and falling water to turn the wheel. Its timbers have been dated to the early seventh century, making it one of the oldest known tide mills anywhere. In 1193 the Cistercians founded Grey Abbey on the eastern shore. Its founder was Affreca, daughter of the King of Mann and wife of the Anglo-Norman John de Courcy, who is said to have vowed to build it after surviving a storm at sea.
Turbines, thrones and gardens
In 2008 a tidal turbine called SeaGen was installed in the Narrows. With twin rotors and a capacity of 1.2 megawatts, it was the first commercial-scale tidal turbine connected to a grid. It generated electricity from 2008 until 2016, and its removal was completed in 2019. Its time in the Narrows taught engineers a lot about tidal energy, and the lough's currents are still seen as an important resource. The lough's grand houses have also made a mark. Castle Ward, on the western shore, appeared as Winterfell in the first series of Game of Thrones. Mount Stewart, on the Ards side, is known for gardens created by Edith, Lady Londonderry, in the 1920s and 30s. It was the family estate of Lord Castlereagh, who was born in Dublin in 1769. Above the northern end rises Scrabo Tower, a Victorian memorial built in 1857 on a hill of volcanic rock. It's a fine spot to take in the whole lough at once, with the drumlins scattered like stepping stones.
What to look out for when you visit
Start at the Narrows. Watch the tide race between Strangford and Portaferry, then take the ferry across to feel it for yourself. Walk or paddle to spot the islands and seals. The Strangford Lough canoe trail threads through many of the quieter corners. Keep a distance from the seals, especially in early summer when pups are on the rocks. On autumn and winter days, look for skeins of Brent geese rising from the mudflats. On clear evenings, the low light picking out the drumlins is one of the best views in Northern Ireland.
Notable people
- St Patrick
- John de Courcy
- Affreca
- Lord Castlereagh
- Edith, Lady Londonderry
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