Rahasane turlough
Encyclopedia
Rahasane turlough is a turlough
, that is a karst
lake, which has no surface outlet and is surrounded on all sides by rising land. It is the largest surviving turlough in Ireland. Water collects seasonally in the basin and drains away only through evaporation or seepage into the underlying limestone. It consists of two basins which are connected at times of flood but separated as the waters decline. It covers 257 ha at an altitude of 10–30m above sea level.
It is situated on the Dunkellin river, west of Craughwell
in south-west Galway
. The site comprises marshes, seasonally flooded wet meadows, with limestone outcrops and scrub at its margins. In the summer the lake empties and the basin is grazed by cattle, horses and sheep.
The southern basin is the more impressive feature, with high rocky sides above an undulating base, strewn with boulders. There is a low hill on the south side of the main basin, and another on
the north-east, near Shanbally Castle
.
Like many other large turloughs it has been threatened with permanent drainage for agricultural improvement, however, it has now been designated a Special Protection Area. It is an important location for migrating birds. It is a very good place to spot accidental visitors from America, such as the American Wigeon
, and from Europe, such as the Black Tern
.
The fairy shrimp
Tanymastix stagnalis
was first recorded in Ireland from the southern basin at Rahasane. It cannot occur in permanent waterbodies as it needs isolation from predators in order to grow to reproductive age.
Turlough
Turlough can mean:* Turlough * Turlough O'Brien Anglicised form of Toirdelbach Ua Briain, King of Munster, effectively High King of Ireland* Turlough O'Neill Ulster chieftain...
, that is a karst
KARST
Kilometer-square Area Radio Synthesis Telescope is a Chinese telescope project to which FAST is a forerunner. KARST is a set of large spherical reflectors on karst landforms, which are bowlshaped limestone sinkholes named after the Kras region in Slovenia and Northern Italy. It will consist of...
lake, which has no surface outlet and is surrounded on all sides by rising land. It is the largest surviving turlough in Ireland. Water collects seasonally in the basin and drains away only through evaporation or seepage into the underlying limestone. It consists of two basins which are connected at times of flood but separated as the waters decline. It covers 257 ha at an altitude of 10–30m above sea level.
It is situated on the Dunkellin river, west of Craughwell
Craughwell
Craughwell is a village and townland in County Galway, Republic of Ireland. The name is also used as a surname, properly Ó Creachmhaoil, though often anglicised as Craughwell and Crockwell...
in south-west Galway
Galway
Galway or City of Galway is a city in County Galway, Republic of Ireland. It is the sixth largest and the fastest-growing city in Ireland. It is also the third largest city within the Republic and the only city in the Province of Connacht. Located on the west coast of Ireland, it sits on the...
. The site comprises marshes, seasonally flooded wet meadows, with limestone outcrops and scrub at its margins. In the summer the lake empties and the basin is grazed by cattle, horses and sheep.
The southern basin is the more impressive feature, with high rocky sides above an undulating base, strewn with boulders. There is a low hill on the south side of the main basin, and another on
the north-east, near Shanbally Castle
Shanbally Castle
Shanbally Castle was built for Cornelius O'Callaghan, the first Viscount Lismore, in around 1810. It was the largest house built in Ireland by the noted English architect John Nash. The castle—located near Clogheen, South Tipperary—was acquired by the Irish Land Commission in 1954...
.
Like many other large turloughs it has been threatened with permanent drainage for agricultural improvement, however, it has now been designated a Special Protection Area. It is an important location for migrating birds. It is a very good place to spot accidental visitors from America, such as the American Wigeon
American Wigeon
The American Wigeon, also American Widgeon or Baldpate, is a species of wigeon in the dabbling duck genus Anas. If this is split up, all wigeons will go into their old genus Mareca again...
, and from Europe, such as the Black Tern
Black Tern
The Black Tern, Chlidonias niger, is a small tern generally found in or near inland water in Europe and North America. As its name suggests, it has predominantly dark plumage.- Description :...
.
The fairy shrimp
Fairy shrimp
Anostraca is one of the four orders of crustaceans in the class Branchiopoda; its members are also known as fairy shrimp. They are usually long . Most species have 20 body segments, bearing 11 pairs of leaf-like phyllopodia , and the body lacks a carapace...
Tanymastix stagnalis
Tanymastix stagnalis
Tanymastix stagnalis is a species of Anostraca that lives in temporary pools across Europe. It may reach up to in some areas and has 11 pairs of bristly, flattened appendages. It swims upside-down and filters food particles from the water...
was first recorded in Ireland from the southern basin at Rahasane. It cannot occur in permanent waterbodies as it needs isolation from predators in order to grow to reproductive age.