Alor - Motonglang (Cathedral)

Setting

A steep, heavily overgrown wall and pinnacle system consistent with the site's "Cathedral" name: one frame shows a narrow, vertical keyhole-shaped swim-through/arch cut through the rock, its walls dark with encrusting growth and two barrel-shaped sponges flanking the opening, small fish silhouetted against the blue beyond (e.g., Image 47).

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Visibility is good on the open-water/blue frames and more turbid/particulate close to the wall, consistent with a wall site with upwelling or current.

General benthic features

Elsewhere the wall face is essentially wall-to-wall encrusting cover rather than open rock: dense mats of red/maroon and pink encrusting sponge and coralline algae, interspersed with patches of green Halimeda-type algae, form a mosaic backdrop punctuated by discrete coral colonies - a round tan brain/faviid-type coral head, small plating colonies with pale growing margins, low mounding colonies with pin-cushion polyps, and a spiky orange soft coral or gorgonian (e.g., Image 20, Image 23, Image 34, Image 44).

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Black bushy growth (consistent with black coral, Antipatharia) recurs on shaded faces alongside a delicate white fan-shaped gorgonian sea fan (e.g., Image 48).

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Large barrel sponges (one prominent ribbed individual over a meter across) and cratered gray sponge colonies with multiple oscula project from the wall in several frames (e.g., Image 3, Image 4, Image 39).

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On the more open, current-swept sections the substrate turns to low-relief rock and rubble with scattered small coral heads, schooling fusiliers and other silvery planktivores streaming past in blue water, and at least three divers with slates/pointers visible working the wall — one frame is a topside boat shot of divers gearing up before entry, included in the folder but not reef content (e.g., Image 26, Image 41, Image 46).

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Coral cover

Coral cover: 5.8% — a blind Claude computer-vision point count of 132 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

No bleaching, disease, or physical damage is visible on any coral colony reviewed; no man-made objects besides diver gear and a thin white line (likely a reef hook or safety line) appear. No crown-of-thorns starfish (COTS) or other corallivores evident.

Fish and other fauna

Reef fish recorded directly include small yellow damsels/butterflyfish, anthias, and a lined/striped fish resembling a lionfish tucked in the reef in one lower-wall frame (not confirmed with confidence) (e.g., Image 45, Image 50).

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Comparisons with other data

Also on record for this site: A steep wall with large openings, swim-throughs, and chamber-like spaces (e.g., Image 6, Image 35).

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Hard corals were discontinuous but diverse, with Montipora/Pachyseris-type plates, Turbinaria, massive Porites, scattered branching Acropora, fungiids, and merulinid brain corals on illuminated ledges and outer wall surfaces (e.g., Image 14, Image 51, Image 52).

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A very large marbled ray (Taeniurops meyeni) is recorded in the dive log. Light shafts and abrupt sheltered-to-exposed transitions define a wall-and-cave system rather than a uniform coral slope (e.g., Image 19, Image 27).

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