Philippines - Coron: Twin Lagoon (island-hopping snorkel)

Setting

Twin Lagoon, Coron Island, Palawan — a snorkel stop on the island-hopping day of 28 January 2017, in the karst lagoons on Coron's south coast.

General benthic features

Shallow coral grows on the lagoon walls and floor, with Seriatopora and Pocillopora acuta among the frames (e.g., Image 1, Image 2, Image 4, Image 5, Image 7).

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Coral cover

Unlike the Coron wreck and El Nido pins nearby, this stop has no DINOv3 pass of its own, so the figure rests on a single method with nothing to cross-check it. Coral cover: 23% — a single-method photographic index. The figure is a CoralSCOP computer vision over 8 frames of Anderson's own photographs, with no second method to cross-check it. CoralSCOP sums retained mask fractions with overlaps possible and segments coral-shaped objects rather than living tissue, so it scores standing dead skeleton as coral and does not measure cover the way a transect does. Against independent point-count surveys it reads high, and the bias is ADDITIVE rather than multiplicative: against 273,968 Catlin Seaview photoquadrats within 2 km of these pins, the relationship is close to his value = their value + about 18 percentage points, with the index appearing to have a floor near 15-20% - it does not report near-zero even where a 50-point count finds 1.0-3.0%. Read a low figure here as an upper bound and a near-zero reef as unresolved, not as the number shown. Anderson considers this CoralSCOP and DINOv3 figure a work in progress and will replace it as soon as a better coral-cover CV model turns up.

Stressors

No crown-of-thorns starfish (COTS) or other corallivores evident.

Comparisons with other data

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

Other notes

Position is from the photographs' own GPS (8 frames), not an estimate.