Lady’s Island Lake

Lady’s Island Lake, County Wexford

A large (350ha) natural sedimentary percolating lagoon, separated from the sea by a sand and gravel barrier and dunes. Substrate grades from soft sandy mud in the north to coarse sandy gravel near the barrier and there are rocks in the southeast. Surrounding land is flat with arable and pasture fields and rough land with rocks. Freshwater enters by a few small streams and leaves by percolation through the barrier. The water level rises in winter flooding farmland and a pilgrimage path and the barrier is usually breached in spring. The lake then becomes tidal until natural closure in 2 weeks – 6 months. Seawater also enters by seepage and overwash of the breach bar. Salinity fluctuates widely according to season and the extent of tidal flow. In October 1996, 4-15‰ was measured at the north end, 23-26‰  near the barrier and 6-10‰ in an isolated pool.