Giant Clam

Aitutaki is an almost-atoll formed around the remnants of an ancient volcanic island, with a broad, predominantly sandy lagoon, an encircling reef, and 15 small motu. Its outer fore reef includes shallow slopes and deeper reef faces exposed directly to the surrounding Pacific. Scientific surveys have documented the effects of cyclones, coral bleaching, crown-of-thorns starfish outbreaks, coral disease, sedimentation, and coastal development on different parts of the reef system. Conditions are not uniform: some fore-reef areas have experienced major coral loss, while healthy branching-coral communities have also been recorded within parts of the lagoon and back reef. This combination of volcanic high ground, lagoon habitats, reef flats, and ocean-facing coral slopes distinguishes Aitutaki from a fully developed coral atoll.

Fun Fact: Aitutaki is classified as an almost-atoll because it retains a substantial volcanic core approximately 124 meters high, estimated to be about 8.1 million years old, within a much younger reef-and-lagoon system.