N. GBR - Green (AUYG41)

Setting

Anderson's notes describe a more protected leeward reef: essentially one larger bommie (more than 40 m across) in a 12-13 m sand apron holding dozens of smaller bommies within 100 m of the GPS point, with a maximum depth of 15-16 m reachable only more than 150 m from that point. The expedition surveyed Yonge Reef as one of its Green (no-take) reefs; under the GBRMPA Zoning Plan the reef is a Scientific Research Zone (no-take, research by permit) with a Conservation Park Zone on its lee side, and the recorded position lies inside the Scientific Research Zone.

General benthic features

Eleven frames were posted from this dive, all reef imagery, and their main subject is a large lobed massive colony. Image 7 and Image 11 both show that colony at close range. Image 7 shows a huge pale cream-gray lobed mass filling the frame against clear blue, its surface broken into rounded lobes and deep valleys. Image 11 closes in further: a fine, even mosaic of small corallites across the whole surface, punctuated by more than a dozen dark curved bivalve shells embedded flush in the living tissue, a scatter of small white patches where the skeleton is exposed, and a green feather star perched on the flank.

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The reef around it is branching-dominated. Image 4 is the strongest frame: a dense thicket of mauve and lilac-gray branching Acropora with pale growing tips, clearly alive, standing over the framework with a yellow-green tabulate Acropora behind it, blue-green plating colonies, sponges, cardinalfish, and damselfish among the branches. Image 3 shows chunky brown columnar and thick-branched colonies rising off rubble in bright blue; Image 1 is a pale lilac branching colony photographed close with tan and rose neighbors; Image 8 and Image 9 are mixed reef shoulders of pale branching colonies, tan massives, and magenta coralline against blue. Image 10 is the crowded-crest frame: rust-brown branching colonies, cream corymbose Acropora, orange sponges, pale mounds, pink coralline, and black feather stars packed within about a meter.

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Coral cover

• Reference: Khaled bin Sultan Living Oceans Foundation, Global Reef Expedition (in situ transect)
• Point-count cover here measured 24%, and Anderson calculated from randomly placed transects that roughly 18% of the surrounding 12-13 m sand-apron benthos was bommie structure.
• One transect was scored at this station (24%; n = 1, so no SE; Living Oceans Foundation per-transect benthic data); it is the expedition's station value printed above.

Stressors

Nothing about this colony reads as recent stress; the white patches are small and isolated against an otherwise continuous living surface. Across 11 of the 14 frames on file no bleaching, disease lesion, or crown-of-thorns feeding scar is visible.

Fish and other fauna

One frame shows the moray: a dark, yellow-flecked moray head wedged into a crevice in pale, silt-dusted coralline framework (e.g., Image 5); his notes call it the "first moray eel of trip." Image 2 is a giant clam lying on clean sand at the edge of the bommie apron, its mantle a dense black-and-green vermiculate pattern with a strongly fluted shell margin; it is a fauna frame over sand and carries no cover information.

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Comparisons with other data

No other surveys have been conducted at this site to date. Within 5 km, twelve independent stations recorded 3.9–66% hard coral cover between 1993 and 2023; the nearest, XL Catlin Seaview Survey at transect 12004, 1.23 km away, read 4.3–7.7% between 2014 and 2017.

Other notes

Position approximate: expedition-estimated (three decimals in the 933-site table); Anderson's sheet and the expedition's planning table carry another day's coordinates for this station.