Key Largo Dry Rocks (Christ of the Abyss)

Setting

Key Largo Dry Rocks is a natural shallow patch/spur reef inside John Pennekamp Coral Reef State Park, and it is known for the "Christ of the Abyss" bronze (often called the Christ of the Deep), which appears in four frames: a wide silhouette on its concrete plinth (e.g., Image 1), a backlit upward view (e.g., Image 2), a closer view of the statue (e.g., Image 3), and a hazier distant view (e.g., Image 5).

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The statue is the only artificial element in the set; everything else is natural hardbottom.

General benthic features

Reef structure across the wide frames is low-relief spur-and-pavement rather than high coral framework: broad turf- and coralline-covered limestone pavement with scattered mounding colonies, cut by sand channels and sand flats that occupy a large share of the frames (e.g., Image 15, Image 22, Image 23, Image 24, Image 21, Image 17, Image 16, Image 19, Image 14, Image 18).

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The overwhelming impression from the reef frames is that this is a gorgonian-dominated bottom. Sea plumes, sea rods, and sea fans form a near-continuous waving canopy over the pavement in Image 25, Image 26, Image 28, Image 29, Image 30, Image 31, Image 33, Image 38, Image 27, Image 9, Image 34, and Image 37, with the erect octocorals rather than stony coral providing most of the vertical structure.

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Sponges are the next most conspicuous element: red and maroon rope and encrusting sponges throughout (e.g., Image 8, Image 30, Image 31, Image 9, Image 34), bright orange encrusting sponge (e.g., Image 9, Image 34), and assorted small tube and lobate sponges scattered on the pavement. Image 8 is the fullest single frame for this — sea fans, sea plumes, red rope sponge, orange encrusting sponge, and small reef fish stacked together on one spur.

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Between the spurs, one frame (Image 13) shows a small isolated patch of gorgonians, sponge, and turf standing alone on open sand, which is the characteristic pattern here.

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Stony corals are present as discrete mounding and encrusting heads rather than as continuous framework, and the close-up frames are what resolve them. Image 32, a colony Anderson identified as Orbicella faveolata, shows a large lobed brown mound beside a sea fan, fully pigmented with no visible paling or recent mortality on the colony. Image 11 is a stand of staghorn among sea plumes (Anderson's identification: Acropora). Image 12 shows a rounded meandroid colony, evenly yellow-brown, sitting on pavement among gorgonians, which Anderson recorded as a healthy brain coral; the colony surface in that frame is intact and uniformly colored. Image 10 shows a large knobby/lobed mounding head with gorgonians and crinoid-like feather growth around it — the same general Orbicella/Montastraea-type habit, but a photograph cannot separate those genera. Image 6 is a big rust-brown mounded organism on pavement whose surface texture in this frame does not settle coral versus a massive sponge. Image 7 is a lower encrusting brown colony on pale pavement.

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Smaller encrusting and plating colonies appear scattered through the wide frames (e.g., Image 9, Image 34) but are not individually resolvable in these photographs. Qualitatively, the frames support a gorgonian- and sponge-dominated low-relief hardbottom with scattered mounding stony colonies and a substantial sand-channel component; a large fraction of the set is sand and open-water frames rather than hard substrate, which any per-frame analysis will have to account for.

Coral cover

• Reference: Claude CV point count (this site's photos)
• Coral cover: 8.3% — a blind Claude computer-vision point count of 23 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

First, condition: no widespread bleaching or paling is apparent, and the colonies that are imaged closely (e.g., Image 32, Image 12, Image 10) are fully pigmented; these photographs were taken on 15 April 2023, before Florida's 2023 summer marine heatwave. In one frame, some staghorn tips appear recently dead and overgrown by fine algae (e.g., Image 11). The pale surfaces that dominate the pavement in frames like Image 4, Image 7, and Image 12 are sand, turf, and crustose coralline, not bleached tissue.

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No corallivores were evident.

Fish and other fauna

Fish and megafauna are well covered. Southern stingrays are the signature of this dive: Anderson's ray frames run from Image 14 to Image 24, several with a diver over the ray (e.g., Image 20, Image 21, Image 23).

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A spotted barracuda-type fish hangs over the reef in Image 35, and a lizardfish rests on rubble in Image 4.

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A parrotfish works the gorgonian reef in Image 8. In one frame (e.g., Image 37) Anderson recorded a shark, which is not resolvable in that frame.

Comparisons with other data

Williams et al. (2014) surveyed this site (Key Largo Dry Rocks), 0.09 km from the pin. Within 5 km, 56 independent stations recorded station-year means of 0.0–41% hard coral cover between 1996 and 2024; the nearest of these, NOAA NCRMP at FLK-27, 0.40 km away, read 11% in 2014.

Other notes

Key Largo Dry Rocks, John Pennekamp Coral Reef State Park and Florida Keys National Marine Sanctuary — the home of the Christ of the Abyss statue, dived on 15 April 2023 (11:21 in, 10.4 m maximum, 58 minutes, 26.8°C average). The statue stands on its concrete plinth in about 8 m of water, the bronze now dark and fully skinned in turf and encrusting growth with small sea plumes rooted along the plinth edge and up the robe. Away from it the site is a gorgonian-and-sponge hardbottom rather than a coral-framework reef: broad pale pavement crusted in coralline algae and turf, carrying dense forests of sea plumes, sea rods, and sea fans; red rope sponges, purple vase sponges, and orange encrusting sponges; and brown fleshy macroalgae. Stony coral is present as discrete colonies within that matrix — meter-scale olive lobed colonies, rust-brown mounding colonies with large open corallites, mustard-yellow mounds — and, importantly, as several separate stands of staghorn coral (Acropora cervicornis), some of them substantial thickets with living golden-tan upper branches. Fish were unremarkable in variety but locally dense: sergeant majors over the ridges, bluehead and yellowhead wrasse, blue tang, and a great barracuda hanging in a groove under a sponge-covered overhang. Twice a southern stingray was photographed digging in the sand with a following escort of snapper and hogfish-type fish taking what it turned up.