Chagos Archipelago - Salomons Island (BISA97)

General benthic features

Acropora leads at 20.91% of the benthos — 38% of all coral — but Porites at 10.96% and Goniopora at 5.00% are substantial, and the fleshy and massive component is unusually well represented: Merulina 3.86%, Goniastrea 3.05%, Lobophyllia 2.09%, Favia 1.46%, Galaxea 0.88%, and Pavona 0.75%. Sixteen further genera fall below 0.5%, including Isopora, Ctenactis, Halomitra, Pachyseris, and Millepora. Non-coral invertebrates hold 11.0% of the benthos, bare substrate 10.9%, coralline algae 9.9%, turf 7.4%, and macroalgae 2.8%. The reef has strong local continuity. One frame shows numerous compact branching colonies packed across the substrate with little open sand; two others add large massive and lobate colonies; two more show tables and corymbose fields extending into the middle distance; and another shows the assemblage continuing across a broad shallow surface (e.g., Image 3, Image 5).

35

Crevices remain between colonies, but living coral occupies much of the visible hard bottom in most frames. The benthic palette includes pink and purple encrusting surfaces, brown foliose growth, small meandroid colonies, and smooth massive heads — the visible counterpart to an 11.0% non-coral invertebrate figure and a genus list this long (e.g., Image 2).

2

The photographs document a densely packed shallow coral garden with massive heads, tables, foliose forms, and heavy encrustation, plus convincing bleaching in both branching colonies and one large table.

Coral cover

Coral cover is 54% (18th of 109) against 23.7% algae (103rd of 109 — among the least algal reefs in the archipelago), and the assemblage carries 28 non-zero coral genera with no single genus taking more than 38% of the coral. The two transects differ in composition more than in cover. D2 carries 50.8% coral across 21 genera and is the Acropora band — 28.25%, with Porites 11.50% and Goniastrea 3.25%. D3 carries slightly more coral at 58.0% across 22 genera but the order flattens completely: Acropora falls to 13.57% while Porites holds 10.43%, Goniopora rises to 10.00% and Merulina to 7.71%*. Assemblage composition. Formal surveys give 54.4% coral, 23.7% algae, and 11.0% non-coral invertebrates across 28 genera, led by Acropora in the shallow band and shared between Porites, Goniopora, and Merulina in the deeper one.

Stressors

Bleaching is evident across multiple growth forms, and this is the most affected site of the batch at 8.8% (37th of 98). One frame shows several compact and thick-branched colonies uniformly cream-white while adjacent colonies retain brown, purple, or green pigmentation. Another frame centers a very large table-like colony pale to white across nearly the entire plate with intact radial branch texture — an unambiguous, high-confidence case. Other wide frames contain scattered white colonies including pale tables and compact branches, and the recurrence across the sequence supports a genuine site condition rather than one anomalous subject (e.g., Image 4).

4

Pale massive colonies and isolated branch tips were deliberately not flagged, since natural coloration, bright shallow illumination at 10.6 m and active growth could all contribute. No crown-of-thorns starfish (COTS) or other corallivores evident.

Fish and other fauna

Fish use the coral relief heavily. Two frames show schools of small fishes concentrated around a large bommie with larger reef fishes above the structure, and a third shows another school in open blue water beyond the coral field (e.g., Image 1).

1

These indicate active habitat use but cannot give standardized density, biomass, or richness, and no individual count is inferred from repeated adjacent frames.

Comparisons with other data

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