St. Eustatius - Chien Tong wreck
Part of the regional summary: St. Eustatius
More about this place: Sint Eustatius on Wikipedia
More info
Leeward Caribbean Islands (NOAA CRW virtual station)An intact steel cargo ship sitting upright on sand, its railings, masts, winch, and cargo hatches still in place and patrolled by a great barracuda. The vertical steel is crusted with sponges and hydroids while the flat decks stay bare, and young maze and star coral colonies have begun to settle on the hull. Wreck and artificial-structure site: this cover value counts coral growing on man-made structure (steel, concrete, wreck debris) and the bottom around it, so it isn't comparable with natural-reef cover, although it is counted in the St. Eustatius regional mean, which pools three artificial structures and one natural reef.
Een intact stalen vrachtschip dat rechtop op het zand staat, met reling, masten, lier en laadluiken nog op hun plaats, en waar een grote barracuda patrouilleert. Het verticale staal is bedekt met sponzen en hydroïdpoliepen, terwijl de vlakke dekken kaal blijven, en jonge kolonies doolhof- en sterkoraal beginnen zich op de romp te vestigen. Wrak- en kunstconstructielocatie: deze bedekkingswaarde telt koraal dat groeit op door mensen gemaakte constructies (staal, beton, wrakresten) en de bodem eromheen, en is dus niet vergelijkbaar met de bedekking van natuurlijke riffen, hoewel ze wel meetelt in het regionale gemiddelde van St. Eustatius, dat drie kunstmatige constructies en één natuurlijk rif samenvoegt.
AI translation of this summary; the English is authoritative.
Eight independent survey stations shown with the program’s logo — click one to see how far it is from this site.
Three other CRD dive sites with their own pages within 5 km shown in orange — click a marker to open its page.
These are unedited originals; edited versions will replace them.
32 of the 50 photographs on this page are shown beside the text that discusses them under "Site description" below.
Site description
Setting
The Chien Tong, St. Eustatius, dived 25 February 2026 as the first dive of the day. The wreck is a steel cargo vessel sitting upright and essentially intact on sand, and the frames read as a tour of a ship rather than of a reef: pipe railings running the full length of the bulwarks, a flat expanse of deck plating with rectangular cargo hatches still square-edged, a horizontal winch drum on its bed, an upright derrick or mast frame with a diver silhouetted through it, and a clean sweep of bow rail shot from below against the surface light (e.g., Image 3, Image 12, Image 13, Image 21, Image 25, Image 26, Image 32, Image 33, Image 39, Image 42, Image 43).
Depth and structure are legible throughout — the hull sides drop straight into dark blue and one frame looks along the sheer line with two divers finning off the plating (e.g., Image 8, Image 9, Image 45).
General benthic features
Colonization is strongly patterned by orientation. The horizontal deck plates are only thinly filmed, still gray and bare-looking, while the vertical hull sides, bulwark edges, railings, and ironwork carry a dense encrusting community: lime-green branching rope sponge, yellow tube sponges (Aplysina-type), a scarlet strawberry-textured sponge, maroon and vermilion encrusting sheets, purple and blue films, filamentous turf, and pink coralline algae (e.g., Image 2, Image 5, Image 17, Image 38, Image 46, Image 49).
A clump of large fleshy tan polyps sits among small plates on encrusted plating (e.g., Image 30); Anderson's frame of the winch crusted with cup corals is not shown.
Stony-coral recruitment onto the hull is the interesting part. One frame catches a clean pairing on bare plating: a yellow-green maze coral (Meandrina meandrites-type) roughly the size of a coaster beside a tan colony with large, deeply cupped, well-separated corallites consistent with Montastraea cavernosa (e.g., Image 48).
Elsewhere a small fleshy-polyped mussid (Isophyllia/Mussa-type) sits in a turf-and-coralline mosaic, and a low domed brain-type colony perches on a bulwark rail (e.g., Image 4).
All are small, young colonies — the wreck is being colonized rather than overgrown (e.g., Image 15, Image 22, Image 37, Image 40, Image 50).
A small red anemone or corallimorph with white tentacles occupies a hole in the encrusted plating (e.g., Image 47).
Coral cover
- Reference: Claude CV point count (this site's photos)
- Coral cover: 3.8% — a blind Claude computer-vision point count of 62 of Anderson's unedited photographs (20 points per photo; water, fish, and obstructions excluded). Other computer-vision methods are listed in the method table.
Fish and other fauna
Sergeant majors and small baitfish work the superstructure (e.g., Image 6, Image 18, Image 35); Anderson's frames of a great barracuda behind the winch and a bar jack off the hull are not shown.
Comparisons with other data
Hoeksema et al. (2022) surveyed this site (Chien Tong), 0.01 km from the pin. Within 5 km, eight independent stations (Reef Check and XL Catlin Seaview Survey) recorded station-year means of 0.7–38% hard coral cover between 2005 and 2013; the nearest of these, XL Catlin Seaview Survey at transect 25015, 1.58 km away, read 2.0% in 2013.
CV model comparison
More info
A few colony-focused photos raise the mean; the median is the typical photo. No computer-vision method yet estimates coral cover accurately on new images, so treat this as indicative rather than a measurement; it is revised as the methods improve.More info
DINOv3 and CoralSCOP were run on the same photos and are listed for comparison. No diver transect exists for this trip, so agreement between the rows is not accuracy, and no computer-vision method yet estimates coral cover accurately on new images; treat every row as indicative.| Method | Hard coral cover (%) | Photos (n) ± SE |
|---|---|---|
| In-house DINOv3 | 16.6 | n = 62 · SE 1.0 |
| CoralSCOP unedited | 12.5 | n = 62 · SE 1.5 |
| Claude | 3.8 | n = 62 · SE 1.0 |
The two computer-vision methods agree within 4.1 pp (12.5–16.6%) and read 8.7–12.8 pp above Claude's blind point count (3.8%); the headline is Claude's blind point count because no transect or manual count exists here.
See a more detailed, stand-alone version of this table.
Independent surveys nearby
| Agency / program | Year(s) | Stations / distance | Link |
|---|---|---|---|
| Reef Check | 2005–2010 | 5 stations, 1.99–3.81 km | Records ↓ |
| XL Catlin Seaview Survey | 2013 | 3 stations, 1.58–4.75 km | Records ↓ |
Coral Reef DiagnosticsYear-average (illustrative only, programs differ)Within 5 km, 8 independent survey stations recorded hard coral cover in 18 surveys between 2005 and 2013. Of the 4 stations surveyed in more than one year, 3 declined (by 1.0–20 points) and 1 increased (by 14 points) between their first and latest surveys. The longest record, Barracuda Reef Line 1 (Reef Check, 1.99 km away), went from 28% in 2005 to 26% in 2010 (mean of 2 surveys). The most recent nearby survey is from 2013, so these values predate recent heat stress. This site's own estimate (3.8%) sits within the range of these station-year means up to 2 km away (0.7–28%); the methods differ, so the comparison is context, not a like-for-like test.
Collected by other programs using different methods (Reef Check uses point-intercept transects; 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 |
|---|---|---|---|---|---|
| Reef Check | Barracuda Reef Line 1 | 2005–2010 | 11–28% (range of yearly means; 6 surveys) | 1.99 km | — |
| Reef Check | Barracuda Reef Line 2 | 2005–2007 | 24–25% (2 surveys) | 1.99 km | — |
| Reef Check | Mushroom Garden Line 1 | 2005–2009 | 9.4–33% (4 surveys) | 3.16 km | — |
| Reef Check | Mushroom Garden Line 2 | 2005–2007 | 24–38% (2 surveys) | 3.16 km | — |
| Reef Check | Twin Sisters | 2009 | 16% | 3.81 km | — |
| XL Catlin Seaview Survey | transect 25015 | 2013 | 2.0% | 1.58 km | doi:10.14264/uql.2019.930 |
| XL Catlin Seaview Survey | transect 25016 | 2013 | 0.7% | 1.65 km | doi:10.14264/uql.2019.930 |
| XL Catlin Seaview Survey | transect 25017 | 2013 | 4.4% | 4.75 km | doi:10.14264/uql.2019.930 |
Data & links
All images from Coral Reef Diagnostics. Data are from Coral Reef Diagnostics and the organizations named in the data sources above.
© Coral Reef Diagnostics.
References
- Hoeksema BW, van der Loos LM, van Moorsel GWNM (2022). Coral diversity matches marine park zonation but not economic value of coral reef sites at St. Eustatius, eastern Caribbean. Journal of Environmental Management 320:115829. DOI
- Gonzalez-Rivero M, et al. (2019). Seaview Survey photo-quadrat and image classification dataset. The University of Queensland (UQ eSpace) data collection. DOI