Indonesia - Halmahera: Failonga

Setting

Failonga is a small island off Tidore, dived on 9 August 2026 during the Halmahera crossing aboard the liveaboard Ambai (Wallacea Dive Cruises). Anderson's field note reads: "a small island normally with strong currents, black tip, turtle, lush foliaceous corals", and the photographs bear out the last phrase emphatically.

General benthic features

The habitats. The dive's signature is a foliose plate garden: broad, pale olive-yellow whorled plates and vases consistent with Turbinaria reniformis and Pavona/Echinopora-type colonies, stacked several tiers deep and running for meters across the upper slope, with tabular and corymbose Acropora growing through them (e.g., Image 1, Image 8, Image 12, Image 18, Image 26, Image 28, Image 33, Image 40, Image 43).

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Below that, a bommie-and-sand slope carries isolated coral heads on open white sediment — the near-zero frames — with the bommies themselves crusted in crimson, orange, and ochre sponges, pink, and mauve coralline algae, tan branching tube sponges, sea whips, gorgonian fans, and feather stars (e.g., Image 14, Image 22, Image 30, Image 34, Image 41, Image 46, Image 47, Image 49).

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A mixed branching zone on the mid-slope runs staghorn and bottlebrush Acropora, Seriatopora, Pocillopora, Stylophora, Porites cylindrica-type stands, Millepora-type fire coral, and pink Dendronephthya, and closes over into an almost continuous Acropora carpet on the upper reef in strong light (e.g., Image 2, Image 5, Image 10, Image 11, Image 13, Image 20, Image 21, Image 31, Image 37).

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The shallow crest is a low-relief pavement of corymbose Acropora and Montipora plates under clouds of anthias and chromis, and one soft-coral garden on the current-swept corner is packed with lilac, tan, and cream arborescent soft corals (Dendronephthya/Scleronephthya/Nephthea-type) over the drop (e.g., Image 24, Image 27, Image 53).

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Coral cover

Coral cover: 33% — a blind Claude computer-vision point count of 201 of Anderson's unedited photographs (20 points per photo; water, fish, and obstructions excluded). Other computer-vision methods are listed in the method table.

Stressors

Condition. One extensive field of standing dead branching Acropora sits on the upper slope, the skeletons still articulated and bound by pink coralline algae and turf, with living Acropora, Pocillopora, and soft coral recruiting through it — an old mortality event of unknown cause, not a recent one (e.g., Image 4).

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No unambiguously bleached colony appeared in the frames reviewed; the two conspicuous white objects in one frame resolve on close inspection as an encrusting sponge and a shell or sponge disc, not bleached coral tissue. No crown-of-thorns, no Drupella aggregations, and no active disease lesions were recorded.

Fish and other fauna

Fauna. A large long-tentacle mushroom coral (Heliofungia actiniformis) with white-tipped tentacles was photographed close up; a giant clam (Tridacna) sat on the mid-slope; and anthias, chromis, damselfish, fusiliers, and butterflyfish were constant (e.g., Image 29, Image 51).

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The blacktip shark and the turtle from the dive log are not resolved in the sampled stills.

Comparisons with other data

No independent survey was made at this exact site; the nearest ones are listed in the table below.

Dive record

The dive reached 29 m at 26–27°C.