The Cefni saltmarsh
This area of coastal marshland, south of the river Cefni, is managed by the Countryside Council for Wales as part of a National Nature Reserve which also includes Newborough Warren and Ynys Llanddwyn. The Cefni estuary is the northernmost part of the dune system which stretches south to Traeth Melynog and Abermenai Point.
In 1810 an embankment was created to hold back the sea and create agricultural land from the vast tidal sand and mud flats which once stretched as far inland as Llangefni. The river was canalised, and ditches dug to make the land dry enough for farming. Since the building of the embankment, the northern sand dunes at Newborough have undergone much growth as sediment bound for Llangefni became trapped at the estuary mouth.
The saltmarsh and tidal sandflats of the Cefni are important feeding areas, especially in winter, for wildfowl and wading birds including pintail, shoveler, redshank, curlew and snipe. The estuary is used as a feeding site by thousands of these birds which migrate south to escape the freezing cold of the arctic. Predators such as peregrine falcon and merlin often visit the estuary, hoping to pick off unsuspecting prey.
Though this is a place of extremes, wildlife has evolved and learnt to live in harmony with the tides and shifting conditions. Salt-tolerant plants such as sea aster and sea lavender, inundated by the sea, anchor themselves to the shifting silt to avoid being taken by the current. The estuary is rich in fish, the main prey of Atlantic grey seals and the elusive otter.
According to Prof Hywel Wyn Owen, the name Cefni derives from the Welsh word “cafn”, meaning dip, hollow or trough. This probably refers to the narrow gorge now called Nant y Pandy or The Dingle, on the outskirts of Llangefni. The name of Llangefni, Anglesey’s county town, reflects its location beside the river Cefni.
With thanks to Prof Hywel Wyn Owen, of the Welsh Place-Name Society, and to Graham Williams