Dongsha, 6 April 2016

Setting

These two dives on 6 April 2016, the day after the Site 6 dive, were at a Dongsha Atoll site whose position was not recorded: Anderson's sample sheet leaves the site blank for both, and its note on the second dive reads "39 km one way from island!". The frames were filed with Site 6, but they show a different habitat, and the sheet's note on the first dive, "No Pdam / No S. hystrix", does not fit Site 6, where eight Pocillopora damicornis colonies were collected the day before.

General benthic features

The dives crossed a lower-relief, more turbid soft-coral flat (e.g., Image 4, Image 46, Image 61).

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Leathery soft corals in gray, mauve, cream, and olive — mushroom-form Sarcophyton and lobed Lobophytum and Sinularia growth forms — are scattered in the hundreds (e.g., Image 20, Image 51, Image 56, Image 59, Image 65) across a pavement of small Pocillopora-form and digitate hard corals, foliose plates, brain corals (e.g., Image 47, Image 70), and one clean gold table Acropora about a meter across (e.g., Image 67), punctuated by vivid scarlet and orange encrusting sponge (e.g., Image 16, Image 54).

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Coral cover

• Reference: Claude CV point count (this site's photos)
• Coral cover: 24% — a blind Claude computer-vision point count of 67 of Anderson's photographs from these two dives, 20 edited and 47 unedited camera originals (20 points per photo; water, fish, and obstructions excluded); median 20%. Soft corals are common here, so a few points on soft corals may have been read as hard coral. Other computer-vision methods are listed in the method table.

Stressors

One brown branching colony has stark-white branch tips (e.g., Image 7), and a massive colony carries many small white spots on its knob tips (e.g., Image 17); both are recent mortality, cause not stated.

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

Fish and other fauna

Fish are conspicuous: dense damselfish aggregations and small purple and blue planktivores over the flat (e.g., Image 33).

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Two frames hold a large barracuda in open blue water (e.g., Image 25).

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Comparisons with other data

No other survey can be matched to this site, because its position was not recorded. If you have survey data from this site to share, please email us.

Dive record

Anderson's sample sheet logs two dives on 6 April 2016 with no site name: Dive 6, in at 12:36 for 33 minutes to a maximum depth of 12.4 m, and Dive 7, in at 13:27 for 23 minutes to 12.8 m. The camera frames run 12:37-12:55 and 13:28-13:47 (70 frames); no water temperature was recorded.

Other notes

Five frames put divers in the picture: one diver working a hose-fed device in a cloud of suspended sediment (e.g., Image 43), and, in the last frames of the second dive, three to four divers gathered on the bottom around a hand-held device fed by a heavy coiled orange hose running up to a cylinder (e.g., Image 64, Image 68, Image 69).

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What that tool is cannot be settled from the frames.