Wet wonderland

THE Fergus estuary and its islands are emerging as among the most “exciting and richest” maritime archaeological landscapes in Ireland, Britain and possibly Europe. This is according to a team from University College Dublin’s School of Archaeology which has been exploring this landscape for the past number of years.

Since 2008 the team, led by Dr Aidan O’Sullivan, has been researching this unique maritime historic landscape.
According to Dr O’Sullivan, “In and around the Fergus estuary there has been evidence of human settlement and activity along the estuary’s banks, in the marshlands and on the islands from prehistory until modern times.
“It is also one of the most remarkable areas of coastal/estuarine wetlands in Ireland, with its vast areas of mudflats exposed at low tide being home for huge flocks of waders and migratory birds. The saltmarshes, mudflats, creeks, islands and reclaimed ‘corcass’ around the estuary thus provide a unique and valuable habitat and environment for Ireland’s wildfowl, plants and wetland fauna.”
Bronze Age wooden structures and early Christian fish weirs were first discovered on the foreshore at low tide, during the Discovery Programme’s pioneering inter-tidal archaeological surveys in the 1990s.
“These investigations confirmed that there was an unusual archaeological and paleo-environmental resource in the estuary that can be used to reconstruct past peoples’ interactions with this dynamic  environment and the character of sea-level and environmental change since the last Ice Age,” explained Dr O’Sullivan.
Funding from the Heritage Council has supported the bulk of this work and, in 2012, has also provided the opportunity to bring together the results for publication. Background cartographic (17th-19th century maps), historical, aerial photographic and archaeological research established a dataset of information about the maritime heritage of the Fergus and its islands.
“Our research of historical maps revealed the presence of piers, quays, causeways, beacons and other natural features between the islands and along the channels – a significant maritime infrastructure around the islands enabling navigation and pilotage.
“Aerial photographic analysis also revealed the survival of previously unknown archaeological sites and enclosures, as well as extensive late medieval field systems on the islands and previously undiscovered harbours and landing places,” said Dr O’Sullivan.
During the surveys conducted between July-September 2009 alone, the Heritage Council-funded project lead to the identification of a total of 69 new archaeological sites. Amongst the most remarkable discoveries have been two Iron Age wooden post alignments with radiocarbon dates of c 100 BC-50 AD.
“Sites from this period are extremely rare in Ireland and to discover one so well preserved is exceptional,” commented Dr O’Sullivan.
Also amongst the most exciting archaeological reveals has been a medieval fishweir complex at Boarland Rocks, 1.5km from dry land.
“Every time we visit this stretch of the estuary more discoveries are made. There are at least 25 fish weirs located over a shoreline 600m in length – essentially an intact medieval fishing landscape. Estimates date these sites to the mid-13th to the early 15th centuries. Almost certainly, these were constructed and used by the inhabitants of the Augustinian Abbey on Canon Island.”
However this remarkable medieval fishing complex, probably the best preserved example yet found from medieval Europe, has a worrying future. In September 2009, an inspection of the Boarland Rock medieval fish weirs revealed they were being eroded much more rapidly than had been suspected – indicating that the sites may be entirely destroyed within 10 years.
“Various strategies are being planned to try and properly record and investigate these sites before they are lost. In 2010 we were again fortunate to get Heritage Council funding in order to experiment with 3D laser scanning.”
In 2011, the team were fortunate to be able to gain a prestigious Marie Curie fellowship (2011-2013), co-ordinated by Dr Rob Sands, UCD School of Archaeology, and conducted by Dr Aoife Daly, a well-respected dendrochronologist, to work on data provided by the tree-rings from the wooden posts of these two fish weirs.
The estuary is part of a larger landscape with a deep heritage and the islands also hold a rich medieval archaeological heritage of churches, holy wells, enclosures and field systems. Around the islands the team have found numerous traces of maritime activities.
Canon Island, the location of the medieval Augustinian abbey is particularly densely surrounded by maritime archaeological features – such as harbours, causeways and reclamation banks to the north and east of the abbey, which are presumably late medieval in date. Deer Island and Coney Island were probably part of the late medieval monastic estates associated with Canon Island.
Dr O’Sullivan went on, “In the 18th century, local labourers and landless farmers were engaged by landlords to graze cattle on the islands. In the late 19th century, the islands saw an explosion of population and were teeming with life with hundreds of people residing there.
“In the post-Medieval period, the inhabitants of the Fergus estuary islands were known to be engaged in fishing, seaweed harvesting and kelp production, as well as in pilotage for ships moving along the Shannon and Fergus estuary channels and in agricultural labour, both tillage and livestock management.
“Our archaeological discoveries have included numerous post-medieval stone walls on the foreshore, sciars in local folklore, relating to seaweed harvesting and kelp production. There are also numerous piers and landing places for boats and navigation, some of which may be medieval in origins.”
“The Fergus estuary and its islands are emerging as amongst the most exciting and richest maritime archaeological landscapes in Ireland, Britain and arguably Europe,” he concluded.

Further information about this project is available on the UCD School of Archaeology website at http://www.ucd.ie/archaeology/research/researcha-z/Fergusestuary/