A turlough (turloch or turlach in Irish [1] ) is a seasonal or periodic water body found mostly in limestone karst areas of Ireland, west of the River Shannon. The name comes from the Irish tur, meaning "dry", and loch, meaning "lake". The water bodies fill and empty with the changes in the level of the water table, usually being very low or empty during summer and autumn and full in the winter. As groundwater levels drop the water drains away underground through cracks in the karstic limestone. [2]
Turloughs are almost unique to Ireland, although there is one example in Wales, Pant-y-Llyn at Cernydd Carmel near Llandeilo. [3] [4] They are of great interest to many scientists: geomorphologists are interested in how turloughs were formed, hydrologists try to explain what makes turloughs flood, botanists study the unusual vegetation which covers the turlough floor, and zoologists study the animals associated with the turloughs.
Turloughs are mostly found on the central lowlands west of the Shannon, in counties Galway, Clare, Mayo, and Roscommon, although a few are also found elsewhere, e.g. in Limerick, Sligo, Longford, and Cork.
Only three turloughs have been identified in Northern Ireland, namely Roosky, Green, and Fardrum Loughs located near Ely Lodge Forest in County Fermanagh. [5] These constitute the most northerly turloughs in Ireland and have been collectively designated a Ramsar site [6] and an Area of Special Scientific Interest. [7] There is one turlough in South Wales, Pant y Llyn. [3]
Rahasane Turlough in County Galway is the largest surviving turlough in Ireland and is an important location for migrating and overwintering birds. [8] It is noted for its greater white-fronted geese, whooper swans, wigeon, teal, and many waders in winter. [9]
Waterbodies analogous to turloughs can be found elsewhere in the world where similar rainfall patterns, rock type and water table occur. In Eastern Canada (Quebec, New Brunswick and Newfoundland) temporary waterbodies called les lacs mystérieux occur.
In continental Europe, seasonal waterbodies called poljes occur in Slovenia, and a karstic waterbody has been described at Clot d’Espolla in Catalonia. [2] It has recently been proposed that the definition of a turlough, particularly as used in the European Union Habitats Directive, [10] be modified to include the Slovenian waterbodies as well as others. The proposed definition is based solely on the physical aspects of the waterbodies, rather than flora and fauna, which differ between Ireland and Slovenia. [11]
When limestone is exposed to rainwater it can dissolve, leading to cracks and joints forming and enlarging. In areas where limestone is at the surface, with very little soil cover, water will drain underground through these cracks rather than running off overground through river and stream systems. The water can then flow underground, emerging later at springs. At times of higher rainfall, the water table will rise, as the underground flow cannot drain all the water, and turloughs will then fill. When the water table drops they will empty again. [12]
Turloughs will usually have specific place on the floor where water flows in and out, called a swallow-hole (slugaire in Irish [2] ). Sometimes an actual hole can be seen, but more often it is a hollow filled with stones. In some larger turloughs the hole will be permanently wet, allowing fully aquatic plants and animals to survive. [12]
Various attempts have been made to classify turloughs into distinct types, such as highland and lowland, fast fluctuating and seasonally fluctuating, or more complex schemes. However, a recent study using multivariate analysis of a wide range of variables characterizing the water bodies shows that there are no distinct types, but rather a continuum from wet to dry. [13]
Turloughs usually have a mixture of aquatic and terrestrial vegetation, occurring in zones depending on the water depth and frequency/duration of filling. In Ireland, the deepest part is characterised by aquatic and semi-aquatic plants such as Chara , Ranunculus , Potamogeton , Littorella uniflora , Polygonum amphibium and Mentha aquatica . This gradually gives way to a sward of Potentilla anserina , sedges such as Carex panicea , and Viola species. The black turlough moss Cinclidotus fontinaloides grows on surfaces such as rocks and tree trunks. Further up the sides of the turlough shrubs like Frangula alnus and Potentilla fruticosa occur. Some turloughs will instead transition to fen vegetation including sedges and bogbean ( Menyanthes trifoliata ). Another characteristic feature is the growth of layers of filamentous algae during warm and dry weather, which later dry out and form "algal paper". [2]
The intermittent nature of these temporary water bodies provides challenges to aquatic animal life. The organisms commonly found in them have adapted various survival strategies, such as aerial adult forms, production of desiccation-resistant resting stages, and amphibious lifestyles. Fish are usually absent (although in larger turloughs sticklebacks can survive by retreating into the swallow-holes), and frogs and newts may sometimes spawn in them. [12] The lack of predatory fish allows some usually rare invertebrates, such as the Cladocera Eurycercus glacialis, to thrive. [14] Other Cladocera common in turloughs include Alona affinis, Alonella excisa, Chydorus sphaericus, Eurycercus lamellatus and Simocephalus vetulus. A number of beetles that are rare or absent elsewhere in Ireland can be found in turloughs, such as Hygrotus quinquelineatus , Coelambus impressopunctatus, Graptodytes bilineatus , Agabus labiatus, and A. nebulosus. [2] Other invertebrates can also occur, such as fairy shrimp, flatworms and snails. [12]
Karst is a topography formed from the dissolution of soluble carbonate rocks such as limestone and dolomite. It is characterized by features like poljes above and drainage systems with sinkholes and caves underground. There is some evidence that karst may occur in more weathering-resistant rocks such as quartzite given the right conditions.
In ecology, a marsh is a wetland that is dominated by herbaceous plants rather than by woody plants. More in general, the word can be used for any low-lying and seasonally waterlogged terrain. In Europe and in agricultural literature low-lying meadows that require draining and embanked polderlands are also referred to as marshes or marshland.
Galway Bay is a bay on the west coast of Ireland, between County Galway in the province of Connacht to the north and the Burren in County Clare in the province of Munster to the south; Galway city is on the northeast side. The bay is about 50 kilometres (30 mi) long and from 10 kilometres (6 mi) to 30 kilometres (20 mi) in breadth. The Aran Islands are to the west across the entrance and there are numerous small islands within the bay. To the west of Galway, the rocks are granite but to the south they are limestone.
The Burren is a karst/glaciokarst landscape centred in County Clare, on the west coast of Ireland. It measures around 530 square kilometres (200 sq mi), within the circle made by the villages of Lisdoonvarna, Corofin, Gort and Kinvara. The area includes such natural features as Mullaghmore hill and Ailladie cliffs, and historic monuments such as Poulnabrone dolmen and Caherconnell Stone Fort. The Burren National Park covers a small part of the Burren and is the smallest of the eight National Parks in Ireland, while the adjacent territory, including the Cliffs of Moher, is included in the Burren and Cliffs of Moher Geopark.
Coole Park is a nature reserve of approximately 1,000 acres (4 km2) located a few miles west of Gort, County Galway, Ireland. It is managed by the Irish National Parks & Wildlife Service, part of the Department of Arts, Heritage and the Gaeltacht. The park is in a low–lying karstic limestone area characterised by seasonal lakes, known as turloughs, which are almost unique to Ireland. It has extensive woodlands. There are 6 kilometres of signposted nature trails plus a formal late 18th century walled garden.
Mushroom stones, or mushroom rocks, in Ireland are limestone boulders undercut by past weathering regimes. These rocks take the form of solitary sentinels of limestone which still bear the unmistakable marks of long-continued erosion by ice, soil or lapping waves at the edge of lakes which have since vanished or retreated. These stones are sometimes shaped like mushrooms, others have an overhang facing in just one direction, but all are notched and undercut in such a fashion as to suggest prolonged exposure to standing water at some time in the past. The mushroom-shaped stones are produced where the notching forms a fairly even circle around the stone.
The Kretschmarr Cave mold beetle is a small mold beetle.
Rahasane Turlough is a turlough, west of Craughwell in southwest County Galway. It is the largest surviving turlough in Ireland.
Carmel National Nature Reserve lies close to the village of Carmel in Carmarthenshire. It lies south of Llandeilo not far from the main road to Llanelli. There is a small car park and picnic site for visitors, and footpaths for access. There is an explanatory notice board at the car park. The site is managed by the Wildlife Trust of South and West Wales and Natural Resources Wales (NRW).
Tanymastix stagnalis is a species of Anostraca that lives in temporary pools across Europe. It may reach up to 2 cm (0.8 in) in some areas and has 11 pairs of bristly, flattened appendages. It swims upside-down and filters food particles from the water. It is the only species of Anostraca in Ireland, having been discovered in Rahasane Turlough in 1974.
Ireland is in the Atlantic European Province of the Circumboreal Region, a floristic region within the Holarctic.
Bladen Nature Reserve in Belize is a landscape of caves, sinkholes, streams and rivers, old growth rainforest and an abundance of highly diverse flora and fauna which includes a great deal of rare and endemic species.
Cernydd Carmel is a Site of Special Scientific Interest in Carmarthenshire, Wales.
The Turlough Hill Power Station is a pumped storage power station in Ireland, owned and operated by the Electricity Supply Board (ESB).
Lough Funshinagh is a lake and Special Area of Conservation in County Roscommon, Ireland, found to the west of Lough Ree. It has been called Ireland's amazing disappearing lake, due to the way it empties quickly - in as little as two days - and unpredictably, sometimes killing thousands of fish. Lough Funshinagh is one of a number of seasonal lakes, or turlough, found in the karst areas of Ireland, west of the River Shannon.
Karst lakes are formed as the result of a collapse of caves, especially in water-soluble rocks such as limestone, gypsum and dolomite. This process is known as karstification. They can cover areas of several hundred square kilometres. Their shallow lakebed is usually an insoluble layer of sediment so that water is impounded, leading to the formation of lakes. Many karst lakes only exist periodically, but return regularly after heavy rainfall.
Rhadine infernalis is a species of troglobitic beetle of the family Carabidae. They are endemic to the county of Bexar, Texas. Within this county, R. infernalis has been found in 39 caves. There are 2 named subspecies of R. infernalis: R. infernalis infernalis and R. infernalis ewersi. There is a third possible subspecies that has not been officially described. R. infernalis was classified in 2000 as endangered under the IUCN Endangered Species Act of 1973, along with 8 other karst invertebrates in the same region. It has the widest known range of the endangered karst invertebrates.
The Nedern Brook Wetland is a flood meadow habitat near Caldicot, Monmouthshire, Wales, designated since 1988 as a Site of Special Scientific Interest (SSSI). The site is of 44.5 hectares and is bridged by the M48 motorway. The spelling Neddern is used in some documents. Nedern Brook is also called Troggy Brook.
Micheline Sheehy Skeffington is an Irish botanist and equity advocate. Elected President of the Botanical Society of Britain and Ireland in November 2022, she was the third woman and second Irish person to hold the position since the Society's founding in 1836.
The Four Roads Turlough Special Area of Conservation is a Natura 2000 site based at the village of Four Roads, Ireland, close to Roscommon town, in County Roscommon, Ireland. The Four Roads Turlough is one of a number of seasonal lakes, or turloughs, found in the karst areas of Ireland, west of the River Shannon.