[4] The islets are breeding colonies for seabirds, including the masked booby (Sula dactylatra), brown noddy (Anous stolidus), white-tailed tropicbird (Phaethon lepturus), lesser frigatebird (Fregata ariel), and great frigatebird (Fregata minor).

[5] The terrestrial portion of the park has rugged terrain, with deep stream valleys separated by ridges.

A large enclave of relatively intact forest remains on the west and south-facing slopes of Mount Mlédjélé.

Native animals include Livingstone's fruit bat (Pteropus livingstonii), which lives only on Mohéli and Anjouan, the Moheli scops owl (Otus moheliensis) and Moheli brush warbler (Nesillas mariae), which are endemic to Mohéli, and other species of birds, reptiles, and insects endemic to the Comoro Islands.

[4] The lake covers an area of 30 ha, and may be linked to subterranean volcanic vents.