N. GBR - Pink (AUHI161)

Khaled bin Sultan Living Oceans Foundation — Global Reef Expedition

Part of the regional summaries: Australia (GBR) - Far North: Pink stations (Preservation Zone reefs) and Australia (GBR)

Photo: Anderson Mayfield/Coral Reef Diagnostics

Country

Australia

Survey date(s)

2014-10-01

Coordinates

-14.4301, 145.4030

Coral cover

43%

Benthic transects+photo-quadrats

Observations

not yet tagged for this site

Heat stress

Today’s heat load

25.2°C 0.0°C-weeks

3 Oct 2026 · No heat stress

5-year thermal stress load

5-year mean max. degree heating weeks (DHW)

11.1°C-weeksⁱ

2021–2025

NOAA Coral Reef Watch — Far Northern GBR virtual station

i 5-year mean max. DHW is the mean of the annual maximum DHWs over the five complete years named above, not conditions today.

More info

Far Northern GBR (NOAA CRW virtual station)

Photographs

1 shown on this page

Site summary

An extensive bommie field on Hilder Reef around 10 m, some heads rising nearly to the surface, with coral cover more than double the algae. Needle corals were dying on four of five transects, alongside a sickly Pocillopora and some dead staghorn framework. Surveyed on the Living Oceans Foundation's Global Reef Expedition.

Max. depth dived

12.8 m

dive-log maximum

Sea surface temp. (satellite)

25.2°C

satellite sea surface temperature (SST) on the survey date (NOAA Coral Reef Watch, Far Northern GBR), not an in-water reading; it is the warmest-pixel (90th percentile) reading in the station area and can run 1–1.5°C above the reef

Bottom time

61 min

in at 10:45

One independent survey station shown with the program’s logo — click one to see how far it is from this site.

Eight 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, Jewell, Hilder, and Eyrie Reefs, northern Great Barrier Reef (Khaled bin Sultan Living Oceans Foundation; opens in a new window)

Site description

Setting

Global Reef Expedition station AUHI161 on Hilder Reef, northern Great Barrier Reef (-14.4301, 145.4030), surveyed on 1 October 2014 on that day's second dive.

What the data say

The in situ benthic transects recorded 43% live coral cover against a 19% algal fraction on a dive to 12.8 m — more than double the algal fraction. Transect mean 43 ± 5.0% SE (n = 2 transects; Living Oceans Foundation per-transect benthic data); the headline above is the expedition's station value. One photograph from the dive is published here.

What Anderson saw

The notes describe an extensive bommie field around 10 m, some bommies rising almost to the surface, with roughly three-quarters of the benthos made up of hard coral-based structure; site-wide in-water estimates ran mostly 15-20% cover, built on Isopora, several Acropora species, massive Porites, and Stylophora pistillata, so this station's transect figure sits well above the diver's general impression. The one published photograph from the dive shows the survey tape running past a bommie capped with lilac and purple fine-branched colonies, with branching and small massive colonies around it over silt-dusted pavement (e.g., Image 1).

Coral cover

Reference: Khaled bin Sultan Living Oceans Foundation, Global Reef Expedition (in situ transect)
Transect mean 43 ± 5.0% SE (n = 2 transects; Living Oceans Foundation per-transect benthic data); the headline above is the expedition's station value.

Stressors

Recorded condition: dying Seriatopora hystrix on four of five transects, plus a sickly Pocillopora damicornis colony and some dead staghorn Acropora framework. Regional context only: the 5-year mean annual maximum thermal stress at the Far Northern GBR virtual station is 11.1 degree heating weeks. No crown-of-thorns starfish (COTS) or other corallivores evident.

Fish and other fauna

Gray reef sharks were logged.

Comparisons with other data

No other surveys have been conducted at this site to date. Within 5 km, one independent station, AIMS manta tow at HILDER REEF, 1.41 km away, read 5.5–40% between 1994 and 2023.

Independent surveys nearby

Within 5 km, 1 independent survey station recorded hard coral cover in 4 surveys between 1994 and 2023. The one station surveyed in more than one year declined by 0.3 points between its first and latest surveys. The longest record, HILDER REEF (AIMS manta tow, 1.41 km away), went from 39% in 1994 to 39% in 2023. One survey since 2021 recorded 39%. This site's own estimate (43%) sits 4 points above the recent value (39%); the methods differ, so the comparison is context, not a like-for-like test.

Collected by other programs using different methods (AIMS manta tow is a towed visual estimate in categorical bins), 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.

Independent survey data near this site
Agency	Site / location	Date	Hard coral cover (%)	Distance	Link
AIMS manta tow	HILDER REEF	1994–2023	5.5–40% (4 surveys)	1.41 km	doi:10.25845/5c09b0abf315a

Data & links

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.