Chagos Archipelago - Eagle Island (BIEA24.5)

General benthic features

Non-coral cover is dominated by turf (35% of all points), with crustose coralline algae 17%.

Coral cover

• This is a ".5" site: informal survey images were annotated in CoralNet, but no formal benthic transect was ever run here.

Stressors

Published bleaching for this informal dive is 28% (Mayfield & Dempsey 2026, Oceans, suppl. S1; published, from 5 photographs). Several colonies here are pink to magenta; whether that is their natural color or a stress response cannot be told from the photographs. Four macro frames are compact branching colonies in a striking pigment range — bubblegum-pink (two frames), a wholly cream-and-tan mottled colony with white branch tips, and the best frame at the site: a deep magenta colony and a cream-tan colony growing shoulder to shoulder on the same head. Mortality is localized, severe where it occurs, and largely invisible to the models. The reference frame: a branching colony in mid-collapse — bone-white branch clusters at the periphery with corallite texture still sharp, pigmented olive-brown branches among them, and a large central mass wholly dead under gray-green sediment-laden turf. A second frame repeats it unannotated; a third shows the eroded skeleton. Structural loss registers as dead coral 3.3% of image area and rubble 1.5%. No crown-of-thorns starfish (COTS) or other corallivores were evident.

Fish and other fauna

Faunally the dive is two things: parrotfish and one octopus. Three consecutive frames capture a large parrotfish school over near-bare sand, the middle one holding a green-and-pink terminal-phase male; the school returns in a later frame with two Moorish idols, a bannerfish, and lined surgeonfish; powder-blue surgeonfish, electric-blue damselfish, and cleaner wrasse fill out the rest (e.g., Image 2, Image 3).

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The site's best animal is an octopus, seen three times — wedged in a crevice with its ribbed pale mantle out, then at close range with eye and sucker plainly visible, then out on open pavement.

Comparisons with other data

Social Ecological Research Frontiers (SERF) surveyed reef fish at a nearby station (GCB Eagle Lagoon), 1.37 km from the pin; we could not confirm that it is the same reef. If you have survey data from this site to share, please email us.