Situated only a few hundred metres southwest of Shannon Airport. A small (2ha) artificial lagoon with a sluiced inlet, formed behind a coastal embankment. There has been considerable debate and controversy in relation to this lagoon, and the possible safety threat of waterbirds colliding with aircraft. When visited briefly in 1996, salinity measured 13psu and water depth was approximately 1m, but when sampled in 2002, a large part of the lagoon was dry and salinity measured 0psu.

Situated on Scattery Island in the River Shannon, 2.5km southwest of Kilrush, Co. Clare. A small (10ha), shallow, “estuarine” natural sedimentary lagoon with a cobble/shingle barrier. A relatively large natural inlet allows most tides to enter through the barrier, and salinity is generally high, ranging from 29-32psu at the time of sampling (18-21/9/03).

This pool lies on the Shannon estuary, just west of Kilcredaun Point, 2 km southwest of Carrigaholt. Small (7ha) natural sedimentary lagoon with a cobble barrier in an area of partially cut peat bog which has become flooded by seawater. Salinity was high at the time of sampling (9-10/8/96) and ranged from 32-34psu in the main pool but is probably less for much of the time. There is a drowned forest of pine, some 4,000 years old on the beach which Mitchell (1990) describes as the finest example of “submerged forest’ that he knows. Further offshore is another barrier of rock, which possibly represents the position of a former complete barrier, enclosing a larger lagoon. The lagoon and cobble barrier, together with the drowned forest, is of great geomorphological interest.

Lough Donnell is situated on the Atlantic coast of County Clare, 4 km south of Quilty. This shallow lagoon is impounded by an impressive cobble barrier, approximately 7 metres high and 40 metres wide. The Annageeragh River, which drains a large catchment area, enters the lagoon in the east and a pipe was constructed through the barrier to prevent excessive flooding of the surrounding agricultural land. Salinity is generally low and ranged from 2-6psu over the main body of the lagoon at the time of sampling (8-9/8/96), but as high as 25psu near the inlet. Barrier breached in December 2007, draining the lagoon. Lagoonal status and future now uncertain.

Situated 4km east of Ballyvaghan, Co. Clare. A small (1ha) natural karst lagoon 500m from the coast with no visible connection to the sea. Not very much is known about this lagoon. When visited on 22/6/96 it was very shallow (<20cm) and salinity measured 14psu, but when sampled on 4/10/06 depth was up to 1m, and salinity was down to 1-2psu. Much of the bed of the lagoon consisted of a calcareous crust and it is possible that the lagoon could dry completely in very dry periods.

Lough Murree is situated on south side of Galway Bay, 12 km west of Kinvarra, County Clare. The lake has formed in limestone bedrock on which a cobble barrier has been deposited along the coastal side. A road now runs along this barrier between the lake and the sea. There is no direct communication with the sea. Seawater may enter the lake occasionally by overtopping of the barrier but the main routes are percolation and possibly through subterranean fissures in the bedrock. The lake has become highly eutrophic, with recurrent algal blooms but remains of interest due to its unusual geomorphology and rare charophyte flora. Galway University has a research station near the lake. Salinity levels varied across the site from 13-24 ‰ at time of survey.

Aughinish Lagoon  is situated on the south side of Galway Bay, 5 km west of Kinvarra, County Clare. A small (8.5ha), shallow (<2m) natural karst lagoon with a sedimentary cobble barrier. A Martello tower was constructed on the barrier and the road leading to the tower originally had a bridged outlet, but the bridge has now collapsed and the road is partly eroded due to changes in the course of the outlet stream. Aughinish is a good example of a shallow, sometimes hypersaline lagoon (34 – 40psu on 5/8/96) with a cobble barrier, fed to an unknown extent by underground channels.

Situated 8.5km west of Kinvarra, Co. Galway. A small (3ha), shallow (<2m) artificial lagoon formed behind a coastal embankment, ranging in salinity at the time of sampling (19/10/06) from 29 to 31psu.