St. Lucia - Anse Chastanet snorkel

Setting

Anse Chastanet, on the coast just north of Soufrière, St. Lucia, snorkeled 2022. This site covers the bay's fringing reef and the resort jetty that stands over it.

General benthic features

The jetty is the most coral-covered surface at the site (e.g., Image 21).

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The pilings carry a dense encrusting community that the surrounding seabed does not match: massive and lobate colonies compatible with Orbicella, Porites astreoides, and Montastraea, and repeated meandroid brain corals compatible with Diploria labyrinthiformis and Pseudodiploria — several the size of a dinner plate and growing directly on the wood (e.g., Image 20, Image 22, Image 23, Image 29).

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One frame shows a vivid green-and-yellow brain coral mid-piling; two others show gray meandroid colonies stacked one above another; two more show whole columns tiled with olive massive colonies, yellow tube sponges (Aplysina-type), red and purple encrusting sponges, Christmas-tree worms, and pink crustose coralline algae (e.g., Image 27, Image 28, Image 34).

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Colonization is uneven between pilings: one frame is mostly turf with only a few small recruits, so the pilings span nearly the full range from bare to heavily settled (e.g., Image 26).

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The natural reef is lower-relief and much more sparsely coralline. The rocky knolls are dominated by turf and purple-maroon crustose coralline algae, with hard coral present as small, scattered massive and encrusting colonies rather than continuous framework (e.g., Image 2, Image 17).

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Sponges and octocorals supply most of the visible structure — yellow tube sponges, orange and maroon encrusting forms, barrel sponges, sea rods, and sea plumes, and pale sea fans compatible with Gorgonia ventalina (e.g., Image 3, Image 4, Image 5, Image 6).

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The single most coral-covered natural frame is the wide reef-top view in "great St. Lucia shot", where mustard-yellow massive colonies, a gray brain coral and stands of yellow tube sponge sit together on a rounded boulder ridge (e.g., Image 1).

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A third of the set is not reef at all. Three frames record conspicuous fleshy macroalgal cover — in one a continuous algal carpet meeting clean sand, and in another a large pale brain coral ringed by brown macroalgae in water shallow enough to show surface ripple (e.g., Image 18, Image 25).

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Coral cover

• Reference: Claude CV point count (this site's photos)
• Coral cover: 7.8% — a blind Claude computer-vision point count of 36 of Anderson's edited photographs (20 points per photo; water, fish, and obstructions excluded). Other computer-vision methods are listed in the method table.

Stressors

Condition. Two frames carry sharply defined white patches on otherwise pigmented massive colonies — one in the foreground and the other on the knoll top. These read as localized tissue loss rather than whole-colony bleaching: the pale areas are discrete and expose skeleton while surrounding tissue holds its color. Cause cannot be determined photographically, and disease, predation, and physical injury all remain possible. Several sea fans appear pale, though color in edited frames is not reliable evidence of condition.

Fish and other fauna

A run of frames shows dense schools of small silver baitfish over rippled white sand, with no benthos in frame; four frames score exactly 0% coral (e.g., Image 9, Image 10, Image 11, Image 14).

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One frame ties the two together, showing the same baitfish massed among the jetty pilings, so the aggregation is a jetty feature rather than an open-water one (e.g., Image 30).

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Fauna. The stand-out record is a spotted snake eel compatible with Ophichthus ophis, photographed twice out on open sand — an unusual thing to catch in the open (e.g., Image 31, Image 36).

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Otherwise: bluehead wrasse (Thalassoma bifasciatum), brown chromis, sergeant majors, damselfishes, and grunts around the pilings, and the very large baitfish schools already noted. No shark, ray, or turtle appears in the reviewed sequence.

Comparisons with other data

Coral cover — independent survey. Reef Check ran a station named "Anse Chastanet Reef" here, recording 17.1% hard coral across 7 surveys spanning 1999–2006. It is context for the site, not a measurement of this snorkel.

Other notes

All 37 frames from the snorkel were examined individually, and they do not describe one habitat: 14 are of the jetty itself, 11 are natural rocky reef, and 12 are open sand, algal flat or baitfish schooling in midwater. That split matters for every number below.