Tonga - Vava'u (TOVA34)

General benthic features

The three shallow habitat frames show a densely occupied reef surface with little exposed sand or open pavement — a close-packed mosaic of small corymbose and digitate Acropora, encrusting and low massive corals, and plating forms, with abundant soft corals (bright yellow-green fleshy colonies) scattered through it; the third frame is dominated by a single large staghorn Acropora thicket growing beside older turf-covered dead substrate (e.g., Image 1, Image 2, Image 3).

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Coral cover

• Reference: Khaled bin Sultan Living Oceans Foundation, Global Reef Expedition (in situ transect)
• Coral cover 50% (LOF-GRE in situ transects; mean of all of this station's own transects).
• Cover is not estimated from any photograph — the 50% figure above is the transect value.
• Transect mean 50 ± 2.5% SE (n = 5 transects; Living Oceans Foundation per-transect benthic data); the headline above is this all-transect mean.

Stressors

Anderson's sampling sheet records all seven Pocillopora colonies sampled here (colonies 56-62) as 20-80% bleached, and the close-ups (e.g., Image 4, Image 5, Image 6) show them white to cream-white with polyps extended.

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The survey notes record many staghorn colonies with wide, turf-encrusted dead branches beneath damselfish algal lawns. The Living Oceans Foundation transects here recorded no cyanobacteria and no recently dead coral.

Comparisons with other data

Coral Health Index 4.24/5 (Mayfield & Dempsey 2025 formula; Mayfield et al. 2021, Platax, Tonga data). "Pete's paradise" — a sheltered lagoonal fringing reef in the Vava'u lagoon, about 50 m from shore. The in-water survey narrative records a shallow reef-flat community running parallel to the land and broken by narrow, deep channels; its edge lies at 4-8 m and slopes at about 45 degrees to 15-25 m. Very wide spurs carry 80-100 cm microrelief with extensive Acropora build-ups and end on a flat sand bottom holding large mounds of staghorn coral, bottlebrush acroporids, scattered tabular acroporids, and large foliose plates. From 20-40 m are further mounds up to 5 m tall dominated by bottlebrush and staghorn acroporids mixed with Echinophyllia, Echinopora, Merulina, Leptoseris, and Pachyseris plates. Cover across the site ranged from 20-80%, high on the sides and in the deep, except that many staghorn colonies carried wide turf-encrusted dead branches beneath damselfish algal lawns. Sampling: 7 Pocillopora colonies were collected at this site (colonies 56-62), all seven labeled Pocillopora acuta by Anderson; each was tagged, photographed whole and then photographed in macro, which is why the site's photo set is dominated by close-ups of those seven animals. Typical recent thermal stress: mean annual maximum of 8.1°C-weeks (Degree Heating Weeks, 2021-2025, NOAA CRW; Southern Tonga virtual station). Coral cover — external cross-reference (Reef Check): two independent measurements, reported side by side and deliberately not averaged. Living Oceans Foundation diver transect (Global Reef Expedition): 50% hard coral (2013). Reef Check: 59% at The Coral Gardens, 1.34 km away (2013, 1 survey). Both were surveyed in the same year; methods differ (Living Oceans Foundation diver transect vs Reef Check point-intercept transect). Reef Check site positions are approximate, and at 1.34 km apart the two surveys may have sampled different patches of the same reef, which is the main caveat on this comparison.

Dive record

TOVA34 (Vava'u): surveyed 22 Sep 2013 during the Khaled bin Sultan Living Oceans Foundation Global Reef Expedition.

Other notes

Photographic record: only three habitat frames exist for this site, all shallow, and they are of modest quality. These frames cover the shallows alone: they cannot settle the slope, the deeper mounds, the zonation, or the site's overall condition, all of which come from the survey narrative and the transect, not from photographs.