Report of deep-sea Porifera (Euplectellidae, Euretidae, Hylanematidae, Pheronematidae, Rossellidae) in the southern Colombian Caribbean.

Study Extent

Anadarko Colombia Company hydrocarbon exploration activities in the Southwestern Colombian Caribbean, include four wells (i.e. Gorgon A-1, Calasu 1, Kronos 1, and Purple Angel C-1), and the other areas of interest (i.e. Chamana, Chamai, Yaduli, Cana Norte, and Cawa). The exploratory wells and areas of interest are localized in the South-western Colombian Caribbean, at depths between 375 m and 2500 m. In general, wells and areas of interest are approximately 54km to 74km offshore from the nearest point in the Caribbean coast of Colombia.

Sampling

Survey areas of interest were assessed using 25 towed camera transects. The cameras registered seafloor features during 3-hour surveys, taking still images every 20 seconds. Benthic and bentho-pelagic megafauna specimens were recorded in the images

Quality Control

Still images and pictures of towed cameras were analyzed twice by the same expert, who did the preliminary identification to phylum and class. All porifera images were then identified to the lowest possible taxonomic level. When in doubt about the identification, additional experts were contacted and the images were sent to them in a .jpg file for towed camera photographs, and as a snapshot (also in jpg format) for ROV videos.

Method steps

1. ROV surveys consisted of 80 meter-long transects in cross fashion, north, south, east, and west, from a central point that could be a transponder (tool for positioning of the drilling vessel) or the exact drilling location.
2. We analyzed a total of 5066 photographs, looking for benthic and bentho-pelagic fauna. The presence of porifera was recorded in the wells Calasu, Chamana, Kronos, CanaNorte, Yaduli, Chamai, Cauwa. Each organism was identified to the lowest possible taxonomic level, and coordinates and depth were registered. We cropped the photographs to include only the organism, and performed image correction to reduce the blueish color cast with the Auto Tone function in Adobe Photoshop CC 2018.
3. Using photographs and video footage, all the organisms were grouped to Phylum and Class. In this paper, we only highlight the occurrences for the Phylum Porifera. Porifera were further identified to the lowest possible taxonomic level, based on comparison with literature, databases and with the help of taxonomic experts from each group. The taxonomy here presented is in accordance to the World Register of Marine Species – WORMS (http://www.marinespecies.org/).

The data presented here corresponds to 81 occurrences (26 of Euplectellidae, 4 of Euretidae, 23 of Hyalonematidae, 3 of Pheronematidae, 9 of Rossellidae) of deep-sea Echinoderm. The taxonomic coverage of this dataset includes 1 class, 3 orders, 5 families, 4 genus and 3 species. There is a 26% classifed to the species level, 14% to class, 11% to family, 5% to order, 43% to genus, and 1% phylum.

1. Hexactinellida
   rank: class
2. Amphidiscosida
   rank: order
3. Lyssacinosida
   rank: order
4. Sceptrulophora
   rank: order
5. Euplectellidae
   rank: family
6. Euretidae
   rank: family
7. Hyalonematidae
   rank: family
8. Pheronematidae
   rank: family
9. Rossellidae
   rank: family
10. Euplectella
    rank: genus
11. Chonelasma
    rank: genus
12. Pheronema
    rank: genus
13. Hyalonema
    rank: genus
14. Chonelasma choanoides
    rank: species
15. Euplectella suberea
    rank: species
16. Pheronema grayi
    rank: species

Anadarko Colombia Company’s hydrocarbon exploration activities in the Southwestern Colombian Caribbean Sea, include four wells (i.e. Gorgon A-1, Calasu 1, Kronos 1, and Purple Angel C-1), and five other areas of interest (i.e. Chamana, Chamai, Yaduli, Cana Norte, and Cawa). The exploratory wells and areas of interest are localized in the South-western Colombian Caribbean, at depths between 120 m and 2568 m. In general, wells and areas of interest are approximately 54km to 74km offshore from the nearest point in the Caribbean coast of Colombia.