Marine Institute
SeaRover Dive Video

D542 Transect RB21 Extensive Lophelia reefs and geogenic colonies on various sediment across the transect with many epifauna such as soft corals, cup corals, sponges, crinoids. Priority 1. Features: Mound, Ridge. Water depth: -940 m. TL: 2 km SOL: 15° 18.149' W 55° 36.105' N

Highlights: Diverse sponges Lophelia reef Antipatharian coral Antipatharian coral Lophelia & crinoids Antipatharian coral & chirostylid Antipatharian coral & chirostylid Antipatharian coral

Coral rubble evident throughout this site. White glass sponges are common and a single vase sponge observed. Madrepora and Lophelia present and increase in abundance moving upslope. Large colonies of these species are observed on top of dead corals on occasion forming full reefs with > 25% living. Motile crinoids and Cidaris cidaris are frequent throughout as are Leiopathes sp., Bathypathes sp., and Stichopathes sp. Towards the end of the dive a series of 8-10 ridges covered in dead/living coral reef are observed.

START VIDEO [00:00:00]/03:19 [1] Gravel/coral gravel/ coral rubble flat/gentle upslope with abundant Aphrocallistes sp. and sparse Madrepora oculata reef (living and dead). [00:06:00] [2] Mosaic sediment (coral framework/coral rubble/coral gravel/sand/mud/sparse cobbles) on a moderate uphill ground where soft corals and Koehlermetra porrecta becomes more frequent as well as a variety of glass sponges. [00:16:00]-[00:18:00] ROV stops for imagery and sampling. The ROV moves sediment, sand cloud obscures the vision. [00:23:00] [3] Dense L. pertusa/M. oculata framework with many species living on top including: soft corals, cup corals, sponges, crinoids, ophiuroids, crinoids, Echinoidea. [00:38:00] [4] Now sediments shift into coral rubble and coral gravel hosting sparse epifauna: crinoids, sponges, soft corals, cupcorals, Actiniaria. [04:23:00] [5] Here coral framework becomes more widespread. Same epifauna. [01:22:00] [6] From this point until the end of the transect, the sediment is interspersed with coral rubble/coral gravel and dense coral framework hosting the same epifaunal community as in previous biotopes. K. porrecta and Leiopathes sp. are the most abundant. [01:19:00] [01:21:00] ROV stops for imagery. [01:23:00]-[01:24:00] blue water for a few seconds, while ROV swims in the water column. [02:01:00]-[02:06:00] Sampling of coral framework and its community. END VIDEO 05:25.

Progression Start Duration Code Name
1[00:00:00]00:08:15M.AtMB.Bi.CorReeAtlantic mid bathyal cold water coral reef (biogenic structure)
2[00:08:16]00:28:25M.AtMB.Bi.CorRee.LopFraMixed coral assemblage on Atlantic mid bathyal Lophelia pertusa reef framework (biogenic structure)
3[00:36:42]00:20:00M.AtMB.Bi.CorReeAtlantic mid bathyal cold water coral reef (biogenic structure)
4[00:56:43]00:18:58M.AtMB.Bi.CorRee.LopFraMixed coral assemblage on Atlantic mid bathyal Lophelia pertusa reef framework (biogenic structure)
5[01:15:42]00:02:03M.AtMB.Bi.CorReeAtlantic mid bathyal cold water coral reef (biogenic structure)
6[01:17:46]00:23:43M.AtMB.Bi.CorRee.LopFraMixed coral assemblage on Atlantic mid bathyal Lophelia pertusa reef framework (biogenic structure)
7[01:41:30]00:04:05M.AtMB.Bi.CorReeAtlantic mid bathyal cold water coral reef (biogenic structure)
8[01:45:36]00:20:04M.AtMB.Bi.CorRee.LopFraMixed coral assemblage on Atlantic mid bathyal Lophelia pertusa reef framework (biogenic structure)

Foraminifera
Syringammina fragilissima : 261 : R
Porifera
Pheronema carpenteri : 347 : R
Aphrocallistes beatrix : 264 : R
cf. Phakellia ventilabrum : 202 : R
cf. Polymastia penicillus : 1137 : R
Porifera cylindrical sp. 2 : 1075 : R
Porifera lamellate sp. 7 : 422 : R
Porifera massive globose sp. 6 : 137 : R
Porifera massive lobose sp. 21 (Hertwigia sp. ?) : 611 : R
Porifera vase (cf. Aphrocallistes) : 1162 : R
Cnidaria
Cerianthidae sp. 1 : 2 : R
Pachycerianthus multiplicatus : 458 : R
Actiniaria sp. 1 : 4 : R
Actiniaria sp. 20 : 605 : R
Phelliactis sp. 1 : 255 : R
Antipathes dichotoma : 1187 : R
Stichopathes cf. gravieri : 283 : R
Phanopathes sp. 1 : 330 : R
Chrysopathes sp. Trissopathes sp. : 540 : R
Leiopathes sp. : 305 : R
Leiopathes sp. (dense) : 612 : R
Antipathella sp. : 320 : R
Bathypathes sp. (brown) : 284 : R
Parantipathes sp. : 1042 : R
Stauropathes arctica : 547 : R

Caryophyllia sp. 2 : 6 : R
Lophelia pertusa : 250 : R
Madrepora oculata : 251 : R
Zoanthidea sp. : 1149 : R
Anthomastus grandiflorus : 278 : R
Anthothela grandiflora : 311 : R
Acanella arbuscula : 585 : R
Acanella arbuscula (firtree) : 991 : R
Keratoisis sp. (fine branching) : 1157 : R
Paragorgia (twiggy) (poss. Swiftia) : 1065 : R
Callogorgia verticillata : 280 : R
Gorgonacea sp. 7 (pink) cf. Isidella : 307 : R
Hydrozoa (bushy) : 50 : R
Hydrozoa (flat branched) : 56 : R
Pliobothrus sp. : 207 : R
Arthropoda
Chirostylidae sp. 1 (indet.) : 285 : R
Chaceon affinis : 254 : R
Munida tenuimana : 339 : R
Caridea (indet.) : 1077 : R
Bathynectes sp. : 235 : R
Munidopsis sp. : 1126 : R
Colossendeis sp. 1 : 1059 : R
Mollusca
Graneledone verrucosa : 973 : R
cf. Grimpoteuthis sp. : 1176 : R
Teuthida sp. 1 : 1017 : R
Echinodermata

Porphyrocrinus thalassae : 9998 : R
Koehlermetra porrecta : 315 : R
Ophiuroidea (indet.) : 1076 : O
Stichastrella rosea : 198 : R
Pseudarchaster sp. 1 : 433 : R
Ceramaster/Peltaster/Plinthaster sp. 1 : 234 : R
Cidaris cidaris : 211 : R
Araeosoma fenestratum : 188 : R
cf. Psolus sp. : 1049 : R
Chordata
Ascidiacea sp. 2 : 20 : R
Galeus melastomus : 1005 : R
Synaphobranchus kaupii : 440 : R
Molva molva : 654 : R
Coryphaenoides rupestris : 566 : R
Lepidion cf. guentheri : 1160 : R
Lepidion eques : 249 : R
Mora moro : 349 : R
Phycis blennoides : 1020 : R
Polyacanthonotus rissoanus : 552 : R
Zoarcidae sp. 1 : 259 : R
Trachyscorpia cristulata : 1216 : R
Neocyttus helgae : 563 : R

Number of species = 72

© Marine Institute, MERC Consultants, Bernard Picton 2022