Indonesia - Halmahera: Lelay Utara (north)

General benthic features

Deep half is a white carbonate sand plain carrying discrete coral mounds, ridges, and isolated bommies rather than continuous reef — shingled foliose plating stands in mauve, pink, and gray (Montipora/Echinopora/Pachyseris/Turbinaria-type) recur throughout, and isolated tabulate Acropora and staghorn thickets stand alone on open sand (e.g., Image 2, Image 4, Image 7, Image 13, Image 19, Image 54).

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Sponge and coralline cover on this deep half is unusually heavy: crimson and maroon massives, blue-gray tubes, teal Neopetrosia-type sponges, and thick pink crustose coralline pavement between the mounds (e.g., Image 28, Image 53, Image 55).

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Transition shows coral closing the gaps between mounds, cover climbing steadily as fish shoals thicken overhead (e.g., Image 8, Image 11, Image 38).

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Shallow plateau is a near-continuous branching-coral field — sprawling fields of corymbose and digitate Acropora, Seriatopora, Stylophora, Pocillopora, pale finger-like Porites, and Millepora, with olive gorgonian and sea-whip bushes standing over them and fusilier and damsel shoals running overhead throughout (e.g., Image 21, Image 24, Image 32, Image 51, Image 52).

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Stressors

A possible bleaching signal on the shallow plateau, read from the photographs. Over the last stretch of the dive, much of the branching-coral field reads noticeably paler than the tan-to-mauve colonies earlier in the same habitat, and the photographs settle it as more than a lighting effect: a discrete colony is stark bone-white against immediately adjacent tan-brown and olive colonies in the same frame under the same light, which rules out white-balance alone (e.g., Image 36).

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The surrounding field carries widespread paling — many colonies pale cream to white rather than the tan/olive/mauve seen on the same growth forms earlier in the dive — consistent with a partial bleaching event across this section of the plateau rather than an isolated colony (e.g., Image 10).

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No dead or algae-covered skeleton was seen alongside the pale tissue, so this reads as active, recent, and partial rather than a completed mortality event. On the deep half, a wire coral rising from the reef beside a sand patch is stark white along its whole length, consistent with a bleached wire coral (e.g., Image 14).

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In one wide frame of the staghorn field, scattered patches of branches are stark white, recent mortality, cause not stated (e.g., Image 44).

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No disease, crown-of-thorns, or predation was seen anywhere in the 175 frames reviewed.

Fish and other fauna

A large sea cucumber crosses the sand.

Comparisons with other data

In 2024, WCS Indonesia surveyed five stations in the Guraici islands, among them one named Lelei (Guraici MPA 2024; data via MERMAID), recording 18–59% hard coral cover. This pin's position is approximate (an island-level placement on the Lelei station, not a dive-site fix), so no station is compared with this site by distance or treated as this site; station names are not dive-site names.

Other notes

Two sharply different habitats in one 29 m dive, which is what drives the spread (Claude: 48% ± 26, range=0.0–100%). A diver's dive-computer check-in gesture opens the sequence and closes it again near the end, bracketing the dive.