Indonesia - Komodo NP: Tatawa Besar

Setting

On the first dive (22 January), the dive-computer average was 25.9°C; Anderson's note reads 24-25°C (cold), and the breathing gas was 30% oxygen. Visibility was poor (8 m), with a high particulate load and a gentle current. This is a typical sloping reef dominated by a fluorescent orange soft coral, with small massive Porites, Diploastrea, Pocillopora verrucosa, giant clams, small digitate Acropora, Platygyra, barrel sponges, Stylophora pistillata, small P. rus, Pocillopora acuta, fire coral, Fungia, and Galaxea; some areas were dominated by massive sponges; the reef's relief and structure were fairly high compared with some reefs in the area. Fish biomass and diversity were high, though mean fish size was small, and the dive turned up a manta 2-3 m across and the first Napoleon wrasse (e.g., Image 1, Image 2).

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On the second dive (27 January), the dive-computer average was 24.8°C, with a minimum of 23.3°C. The breathing gas was again 30% oxygen. It is entirely possible that we were diving in the middle of an upwelling event given the poor viz (5-6 m) and cold temperatures (23-24°C) (e.g., Image 4).

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Water looked nutrient-rich, and fish life was more impressive than at many other sites.

General benthic features

Coral was very abundant. Stylophora pistillata was common, alongside Hydnophora, Pocillopora eydouxi, Isopora, some table Acropora, finger Porites, and green Tubastraea, and Acropora diversity was high. There was not much coral above 11 m. Seriatopora hystrix, fire coral, and soft corals were all common in the shallows. Large rubble areas at 5-7 m were dominated by soft corals, and another manta appeared at the end of the dive (e.g., Image 5).

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Huge sponges dominated the habitat in many places. Coral cover was high, and the reef was very colorful. Hard corals and sponges dominated the habitat for most of the dive. Some coral rubble was being colonized by crustose coralline algae and other algae. Soft corals were dominant only in the shallows (3-5 m).

Coral cover

• Reference: Claude CV point count (this site's photos)
• Coral cover: 22% — a blind Claude computer-vision point count of 155 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

On the 27 January dive, one salmon-red table colony has an algae-covered dead center ringed by a band of stark-white bare skeleton, a band of recent mortality, cause not stated (e.g., Image 51).

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

Fish and other fauna

A blacktip reef shark was seen. A turtle was seen. Reef fish biomass was high. A dogtooth tuna was seen, one of few on the trip.

Comparisons with other data

WWF-US and WWF-Indonesia surveyed a nearby station (TNK06), 0.48 km from the pin; we could not confirm that it is the same reef. Within 5 km, five independent stations (Reef Check and WWF-US / WWF-Indonesia) recorded station-year means of 8.8–51% hard coral cover between 2016 and 2020; the nearest, WWF-US / WWF-Indonesia at TNK06, 0.48 km away, read 40% in 2016.

Dive record

The first visit was dive 3 of 22 January 2019 (trip dive 14). It ran from 14:52 to 15:50 (58 min). Maximum depth was 18 m. The return visit was dive 2 of 27 January 2019 (trip dive 33; Anderson's 30th dive of the trip), from 10:30 to 11:28 (58 min). Maximum depth was 18.3 m.

Other notes

Though a virtual repeat of our previous dive to this site, it was nevertheless lovely. Anderson shivered for essentially the whole dive.