Part of the regional summaries: Australia (GBR) - Far North: Green stations (no-take reefs) and Australia (GBR)
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Far Northern GBR (NOAA CRW virtual station)A patchy, sand-swept bommie field on Unnamed Reef 74 where one coral head is so thickly wrapped in glassfish that the coral behind is barely visible, and a big golden stand of fire coral arches over another, at 52% cover. A gray reef shark and a silvertip shark were the wildlife highlights, with no bleaching, disease, or crown-of-thorns. Surveyed on the Living Oceans Foundation's Global Reef Expedition.
Two independent survey stations shown with the program’s logo — click one to see how far it is from this site.
Six other CRD dive sites within 5 km shown in orange — click a marker to open its page.
🗺 Detailed map of the Global Reef Expedition dive sites, Five Reefs and unnamed reef 11-238, northern Great Barrier Reef (Khaled bin Sultan Living Oceans Foundation; opens in a new window)
10 of the 29 photographs on this page are shown beside the text that discusses them under "Site description" below.
Site description
Setting
Anderson's second Unnamed Reef 74 dive found a patchy, sand-swept bommie field in 5-10 m visibility, with rubble taking over past 16 m. Between the bommies the floor was open, rubble-flecked sand, crossed on this dive by a reef shark (e.g., Image 7).
General benthic features
The photographs are dominated by the bommies themselves. Two frames show a single head so thickly wrapped in glassfish that the coral behind them is barely visible, its flanks encrusted with purple and blue sponges, red coralline crusts, and a black feather star with its arms fanned into the current (e.g., Image 1, Image 2).
Elsewhere the reef is a mixed, colorful jumble: orange and cream soft corals, tabulate and corymbose Acropora, small mounding Porites, and one big golden stand of branching fire coral (Millepora) arching over the frame with damselfish scattered above it (e.g., Image 3, Image 4, Image 5).
One bommie rose as a near-vertical wall straight off the sand, stepped with tabular Acropora plates and small corymbose colonies (e.g., Image 9).
Lower heads were capped with corymbose and branching Acropora, lilac branching colonies, small massive mounds, and a patch of bright red encrusting growth (e.g., Image 8).
On a shaded flank, lilac leathery soft corals and finger-lobed soft corals grew below a pale lilac branching colony, with dark, fine-branched colonies filling the overhang (e.g., Image 10).
Fire coral, high Acropora diversity, Stylophora pistillata, and Pocillopora verrucosa filled the shallow 5-6 m band.
Coral cover
- Reference: Khaled bin Sultan Living Oceans Foundation, Global Reef Expedition (in situ transect)
- The point-count survey read 52% live coral on a dive to 22.0 meters, drawn from a site where readings elsewhere swung from under 1% on bare rubble to about 70% at the base of the most continuous structure.
- The survey tape ran up the side of one bommie through corymbose Acropora, orange soft corals, and small massive colonies (e.g., Image 6).
- Transect mean 52 ± 4.0% SE (n = 8 transects; Living Oceans Foundation per-transect benthic data); the headline above is the expedition's station value.
Fish and other fauna
A gray reef shark and a silvertip were the day's wildlife highlights, and no bleaching, disease, or crown-of-thorns starfish were noted.
Comparisons with other data
No other surveys have been conducted at this site to date. Within 5 km, two XL Catlin Seaview Survey stations recorded 16–32% hard coral cover between 2012 and 2016; the nearest, XL Catlin Seaview Survey at transect 15022, 3.46 km away, read 17–32% between 2012 and 2016.
Nearby citizen-science imagery within 2 km (not a survey of this site, and not total coral cover):
- Great Reef Census (citizen science, AI + volunteer image analysis): branching Acropora 0.6%, plating Acropora 2.0%, massive corals 8.2% of colonizable substrate, 20 images, 2022-11-26, 0.77 km.
- Great Reef Census (citizen science, AI + volunteer image analysis): branching Acropora 5.0%, plating Acropora 3.1%, massive corals 9.3% of colonizable substrate, 21 images, 2022-11-26, 1.63 km.
The Great Reef Census scores three coral shapes only, so every other coral is left out, and its denominator is colonizable substrate (sand, water, and shadow excluded): these values are not hard coral cover and should not be added together or compared with the cover figures on this page. The photographs are taken by volunteer snorkelers 3–5 m above the reef. In the program's own validation (Lawson et al. 2025, Environmental Monitoring and Assessment 197:814, doi:10.1007/s10661-025-14261-6, open access), each analysis method on its own differed from expert estimates by up to about 9.5 percentage points on average for these coral types (AI alone: plating Acropora −9.1 points; AI plus volunteers: branching Acropora +9.5 points); the program's “~99% accurate” figure is the average over about 8,000 images after choosing the better method for each coral type, and site values from fewer images carry more error. Sites with fewer than 40 images have fewer images than the 40–80 the method needs to estimate site-level values to within 5 percentage points. Source: Great Reef Census / Citizens of the Great Barrier Reef; Lawson et al. 2026, Limnology & Oceanography Letters, doi:10.1002/lol2.70168 (data CC BY-NC 4.0, doi:10.7910/DVN/KCULSD).
Independent surveys nearby
LOF Global Reef ExpeditionYear-average (illustrative only, programs differ)Within 5 km, 2 independent survey stations recorded hard coral cover in 4 surveys between 2012 and 2016. Of the 2 stations surveyed in more than one year, 1 declined by more than 7 points between their first and latest surveys; 1 changed by 7 points or less, inside the 7-point method-noise floor (inconclusive). Two stations share the longest span (2012–2016); one, transect 15022 (XL Catlin Seaview Survey, 3.46 km away), went from 32% in 2012 to 17% in 2016. The most recent nearby survey is from 2016, so these values predate recent heat stress. This site's own estimate (52%) is not compared with these surveys: none lies within 2 km.
Collected by other programs using different methods (the XL Catlin Seaview Survey uses photo-transects with automated image annotation), so these are context for the figures above, not a like-for-like comparison. Where a station was surveyed more than once, the cell shows either the range of its values or, as a single value, the mean of surveys made in one year. Station names are not dive-site names.
| Agency | Site / location | Date | Hard coral cover (%) | Distance | Link |
|---|---|---|---|---|---|
| XL Catlin Seaview Survey | transect 15022 | 2012–2016 | 17–32% (2 surveys) | 3.46 km | doi:10.14264/uql.2019.930 |
| XL Catlin Seaview Survey | transect 15024 | 2012–2016 | 16% (2 surveys) | 3.99 km | doi:10.14264/uql.2019.930 |
Data & links
- Download benthic survey data (CSV) ↗
- Download all LOF-GRE data (933 sites) ↗
- Photo portfolio ↗
- Coral Reef Diagnostics country page ↗
All images from Coral Reef Diagnostics. Data are from the Khaled bin Sultan Living Oceans Foundation Global Reef Expedition, Coral Reef Diagnostics, and the organizations named in the data sources above.
© Coral Reef Diagnostics.