[6] The ecology of Carrickaport lough, and other county waterways, is threatened by curly waterweed, zebra mussel, and freshwater clam invasive species.

[7] The lake takes its name from the bordering townland of "Carrickaport" (Irish: Carraig an Phoirt), meaning the "rock of the port (or fort, or bank)".

The lake has an hourglass shape with a surface-area of about 0.46 square kilometres (0.2 sq mi),[1][2] and depths of 7 metres (23.0 ft).

[12][7] Carrickaport Lough is reed-fringed,[3] with approximately one fifth of substrate vegetation being common club-rush, while Potamogeton pondweed and the alien species Elodea canadensis are also present.

[14] In August 2000 the "Weissia rostellata" moss, regarded as a rare species in Ireland,[15] was found growing unshaded to partly-shaded (by grasses and rushes) on the damp clay-mud of a sparsely vegetated ditch beside the lake.