[1] The ecology of Keshcarrigan Lough, and other county waterways, is threatened by curly waterweed, zebra mussel, and freshwater clam invasive species.

[4][5] The lake is named from the bordering townland of "Keshcarrigan" (Irish: Ceis Charraigín), meaning the "Kesh, or causeway, near the little rock".

The lake forms a tilted oblong shape, with a surface-area of 0.39 square kilometres (0.2 sq mi),[1][6] with depths of 4 metres (13.1 ft).

Fish present in Keshcarrigan Lough include "roach-bream hybrids", Roach, Perch, Bream up to 4lbs, and Pike.

[8] Keshcarrigan Lough, with a shallow rocky shore, has some ideal potential white-clawed crayfish habitat,[9] but the ecology is seriously threatened by zebra mussel infestation,[10] and indiscriminate importation of non-indigenous crayfish species.