WaterwaysNet: Blackwood Feeder Project

Ecology of the Blackwood Feeder

Blackwood Feeder and Reservoir are one of the most important ecological sites in Co. Kildare. Since the level was lowered in the 1950s the reservoir has developed into a semi-natural shallow alkaline lake with some interesting plant communities. Alkaline fen vegetation occurs at the lake edge, notably a plant community dominated by Blunt-flowered Rush and Black-bog Rush, with frequent sedges. Other species in this area include Marsh Marigold, Red Rattle, Arrow Grass, Water Mint and Bulrush. Extensive stands of Reed, Bulrush and Bottle Sedge occur around the open water. A stand of Great Fen-sedge occurs in the western corner. The lake contains patches of emergent vegetation in the middle as well as around the shore.

Submerged plants include Starwort and Bladderwort, with Duckweed and the liverwort Riccocarpus natans occurring on the surface. Acid grassland, heath and bog surround the lake. Here the vegetation includes Bent Grass, Purple Moor-grass, Bog Myrtle, Bracken, Gorse and Ling Heather. Wet woodland of Birch, Willow and Alder occurs in the north-western corner of the lake. A high diversity of mollusc species is found on the site (42 species recorded in 1997).

The Ballynafagh Lake is of particular conservation significance for the presence of populations of the rare De Moulin's Whorl Snail (vertigo moulsiniana).

Another rare mollusc pisidium pseudosphaerium was recorded at the south end of the feeder a number of years ago but has now disappeared.

The rare Marsh Fritillary butterfly was present at the site a number of years ago but was not recorded in recent surveys.

While the site has a plentiful supply of the species food plant (Devils Bit Scabious) it is believed that the lack of grazing at the site makes the height and struture of the vegetation unsuitable as a habitat.

Recent survey work has confirmed that otters frequent the lake and badgers are also believed to be present.

The site supports a diverse community of resident and wintering waders, wildfowl and other bird species. Whooper swans were using the lake in the 1980s but have not been seen for some time.

The site has been designated as a candidate Special Area of Conservation (cSAC) under the EU Habitats Directive. (Site code 001387).