N. GBR - Blue (AU3973)

Setting

Global Reef Expedition station AU3973 on Unnamed Reef 11-039, far northern Great Barrier Reef (-11.2464, 143.2569), surveyed on 15 September 2014 in a Habitat Protection (Blue) Zone, where line fishing is permitted.

General benthic features

The notes describe a reef that only really begins around 10 m and gains coral and diversity going shallower, peaking at 2-3 m; staghorn Acropora, massive Porites, and large Diploastrea were common at 3-7 m, where he estimated 50-70% live coral cover with more than 40 species. The surveyed transects, all at 9.5-10.5 m, sat at the sparser lower edge, logging patches of dead Acropora framework and a few dying Echinopora plates among soft corals, favids, and small massive poritids, under a very high sediment load (8-10 m visibility). Porites was the most common coral genus on this station's transects (14% of the benthos), followed by Diploastrea (4.7%), Pectinia (4.0%), and Goniopora, Pachyseris, and Psammocora (3.3% each); bare substrate covered 31%, the largest non-coral class. Among the algal classes on this station's transects, sediment-laden turf (16%) led, followed by turf (1.7%) and cyanobacteria (0.3%).

Coral cover

• Reference: Khaled bin Sultan Living Oceans Foundation, Global Reef Expedition (in situ transect)
• The expedition's in situ point-count transects at this station recorded 49% live coral cover against 18% total algal cover.
• Transect mean 49 ± 12% SE (n = 3 transects; Living Oceans Foundation per-transect benthic data); the headline above is the expedition's station value.

Stressors

Regional context, not an observation here: surveyed about eighteen months before the 2016 mass bleaching, an event that severely bleached hundreds of reefs on the northern Great Barrier Reef (Hughes et al. 2017); 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

A striking flatworm was the notable non-coral record (e.g., Image 7, Image 8).

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Comparisons with other data

No prior survey data from this site. If you would like to share yours, please email us.