Sheskinmore Lough is a designated Special Protection Area (SPA) and a Special Area of Conservation (SAC) and is located on the west coast of Ireland, a few miles north of Ardara, Donegal. The site comprises a diverse array of coastal habitats including a sedimentary shallow lake, calcareous grassland, saltmarsh, intertidal sand flats, swamp, fen and wet grassland, which all support a plethora of rare and endangered plant and bird species many of which are protected under EU legislation. The solid geology underlying the site is almost completely obscured by dune sand, however an exposed granitic intrusion of higher ground fringes the northern and eastern sides of the lake.
Sheskinmore Lough itself is a shallow sedimentary lake that is fed by the Duvoge and Abberachrin rivers. The lough was formed about 1000 years ago when dune remobilisation separated the Duvoge and Abberachrin river branches from the main Loughros More estuary, resulting in their impoundment and the development of a shallow lake. Since its isolation, salinity has decreased within the lough and it is now classed as freshwater. To maintain water levels for roosting birds and rare plants within the lough, a sluice was installed in the outflowing river by the National Parks and Wildlife Service (NPWS).
The lough is surrounded by well developed swamp vegetation dominated by Common Reed (Phragmites australis), along with such species as Grey Club Rush (Scirpus lacustris subsp. tabernaemontani) and Bottle Sedge (Carex rostrata). Within the lough itself are a number of important charophyte species as well as the rare and protected Slender Naiad (Najas flexilis). A small area of fen is found close to the lough containing Black Bog Rush (Schoenus nigricans), various sedge species (Carex spp.) and Purple Moor Grass (Molinia caerulea). Wet grassland is also present close to the lough, with rush species (Juncus effusus, J. acutiflorus and J. articulatus), which dominate, and a range of herb species such as Cuckooflower (Cardamine pratensis), Meadowsweet (Filipendula ulmaria) and Tormentil (Potentilla erecta).
A significant feature of the site is a small area of calcareous grassland with important orchid populations, including the very localised Dense-flowered Orchid (Neotinea maculata). The grassland and marsh habitats merge with machair and an extensive sand dune system, which includes Marram dunes, fixed dunes and decalcified dune heath. Marram grass (Ammophila arenaria) is frequent along with such species as Sand Sedge (Carex arenaria), Red Fescue (Festuca rubra), Yarrow (Achillea millefolium), Lady’s Bedstraw (Galium verum), Bird’s-foot Trefoil (Lotus corniculatus), Common Dog-violet (Viola riviniana) and Pyramidal Orchid (Anacamptis pyramidalis). The dune system is bounded to the west by Trawmore Strand and to the south by Ballinreavy Strand. Saltmarshes are well developed within the site and typically support plant species including Common Scurvy Grass (Cochlearia officinalis), Sea Pink (Armeria maritima), Buck’s-horn Plantain (Plantago coronopus), Sea Plantain (Plantago maritima), Sea Milkwort (Glaux maritima), Lax-flowered Sea-lavender (Limonium humile) and Sea Rush (Juncus maritimus). The site also includes the outer part of the Owentocker Estuary where intertidal sand flats are exposed at low tide.
Sheskinmore Lough was formerly of importance for its internationally regarded Greenland White-fronted Goose (Anser albifrons flavirostris) and Barnacle Goose (Branta leucopsis) wintering populations. Since the 1980s, however, goose numbers at the site have declined markedly. Nevertheless, the Greenland White-fronted Goose population at Sheskinmore Lough is still significant as it is one of the few flocks using traditional habitats including two bogland feeding sites. The site also supports small numbers of other waterfowl species including Teal, Mallard, Snipe and Lapwing. Another important feature of Sheskinmore Lough is the large number of Chough (Pyrrhocorax pyrrhocorax) that frequent the area throughout the year, especially in winter. This nationally important population, which nest elsewhere on the coast, feed and socialise within the site with over 100 birds counted on occasions.