Marine Institute
SeaRover Dive Video

D555 Transect PB25 Diverse epifauna on mud/cobble/carbonate substrata with Pennatulacea and many species of crinoids. Priority 1. Features: NPWS selected. Water depth: -2600 m. TL: 3.4 km SOL: 15° 13.152' W 51° 48.087' N

Highlights: Bamboo coral & starfish Sea pen & brittlestar Hexactinellid sponge Brisingid starfish Yellow stalked crinoids - Anachalypsicrinus nefertiti

Soft sediment with cup corals, the occasional Anthomastus sp. and sea pens are observed here. Evidence of infauna is noted due to the presence of bioturbation, burrows and mounds. Circular markings in sediment are common. High densities of Echinus sp. of all sizes were noted locally. On a steep black cliff with mud overlay species richness is poor. Some holothurians, asteroids, ophiuroids, sponges and stalked crinoids are observed. Bathypathes sp. and Lepidisis sp. are observed in very low numbers. This area is species poor. Heavy marine snow reduced visibility towards the end of the dive. Species of note are the sea pen Distichoptilum gracile and anemones Corallimorpharia spp.

VIDEO A STARTS AT [00:00:00]/09:47. Marine snow present throughout the entire transect. [1] Muddy sediment on gentle upslope. Various species of isolated scleractinian present. Sparse epifauna. Throughout the dive. [00:09:00] ROV stops for imagery of Echinodernata. [00:10:00] Mud Cloud/vision obscured. [00:13:00] ROV stops for imagery of anemone and dead sponge. [00:15:00] a few inlets on muddy sediment, possible fauna burrow. [2] [00:25:00] muddy sediment with dominant white Echiuroidea (OTU1129). [3] [00:26:00] Now muddy/pebbles field with sparse epifauna. [00:29:00] ROV stops for imagery of Distichoptilum gracile with associated ophiuroid. [00:32:00] Here a large species of dead sponge. [00:35:00] ROV stops for imagery of unknown porifera vase (poss glass sponge). [4] [00:49:00] Now mosaic substrata, including exposed bedrock with patches of muddy sediment on steep wall. Bathycrinidae OTU1141 dominates on hard substrate, ophiuroidea OTU1076 on muddy sediment. [5] [00:54:00] Bedrock/cobbles/pebbles/mud on steep wall with crinoids and ophiuroids co-dominate. [6] [00:58:00] Bedrock and mud on vertical wall where crinoids and ophiuroids continue to dominate. [01:40:19] ROV stops of imagery of anemone OTU900. [7] [01:45:00] Here mud/sparse pebble/cobbles field with sparse Bathycrinidae. [01:47:00] ROV stops for imagery of Corallimorphidae OTU43 and Democrinus OTU1103. [8] [01:56:00] boulders/cobbles/mud mosaic biotope with dominant crinoids and anemones. [9] [02:01:00] Mud/pebbles fields with sparse epifauna. [10] [02:02:00] Boulders/cobbles/mud with Bathypathes and crinoids. [11] [02:05:00] Here cobbles/mud with ophiuroids. [12] [02:07:00] Carbonate boulders/cobbles/mud. [02:10:00] Poor vision/suspended sediment/marine snow. [13] [02:18:00] Carbonate slope with stalked crinoids and antipatharians. [02:23:00] [14] Now carbonate vertical wall with inlets. Bathycrinidae and Stichopathes sp. overhanging until VIDEO A ENDS [02:27:00]/12:14.

VIDEO B STARTS AT 12:16. Carbonate bedrock/terrace with sparse cobbles. Stichopathes sp. and Anthomastus grandiflorus co-dominate. [02:30:00] Thick marine snow. VIDEO B ENDS 12:18.

N.B. In this dive, large fish species (up to a 1 m in length – ID to be confirmed) observed.

N.B. Unknown species of fluffy tufts are present as well as ‘fairy rings’ on the sea floor

Progression Start Duration Code Name
1[00:00:00]00:25:38M.AtUA.MuAtlantic upper abyssal mud
2[00:25:39]00:01:19M.AtUA.MuAtlantic upper abyssal mud
3[00:26:59]00:24:12M.AtUA.MuAtlantic upper abyssal mud
4[00:51:12]00:09:24M.AtUA.RoAtlantic upper abyssal rock and other hard substrata
5[01:00:37]00:48:03M.AtUA.RoAtlantic upper abyssal rock and other hard substrata
6[01:48:41]00:11:30M.AtUA.MuAtlantic upper abyssal mud
7[02:00:12]00:05:06M.AtUA.RoAtlantic upper abyssal rock and other hard substrata
8[02:05:19]00:01:02M.AtUA.MuAtlantic upper abyssal mud
9[02:06:22]00:03:18M.AtUA.RoAtlantic upper abyssal rock and other hard substrata
10[02:09:41]00:02:07M.AtUA.RoAtlantic upper abyssal rock and other hard substrata
11[02:11:49]00:10:54M.AtUA.RoAtlantic upper abyssal rock and other hard substrata
12[02:22:44]00:04:26M.AtUA.RoAtlantic upper abyssal rock and other hard substrata

Foraminifera
Syringammina fragilissima : 261 : R
Porifera
Geodia atlantica : 1205 : R
cf. Geodia baretti (Porifera massive globose sp. 11) : 601 : R
Porifera cylindrical sp. 2 : 1075 : R
Porifera encrusting sp. 1 (white) : 1 : R
Porifera encrusting sp. 15 (yellow) : 58 : R
Porifera lamellate (bubbles) : 1156 : R
Cnidaria
Cerianthidae sp. 1 : 2 : R
Actiniaria sp. 20 : 605 : R
Actiniaria sp. 21 : 900 : R
Actiniaria sp. 24 : 907 : R
Adamsia sp. : 1066 : R
Stichopathes sp. : 560 : R
Bathypathes sp. 1 : 328 : R
Stauropathes arctica : 547 : R
Corallimorphidae sp. 2 : 43 : R
Caryophyllia sp. 2 : 6 : R
Caryophyllia sp. 5 (bullseye) : 584 : O
Flabellum sp. : 1056 : O
Anthomastus grandiflorus : 278 : R
Chrysogorgidae sp. 1 : 1008 : R
cf. Clavulariidae sp. : 289 : R
Acanella arbuscula : 585 : R
Pennatulacea sp. 3 (submerged axis) : 1191 : R
Kophobelemnon stelliferum : 442 : R
Distichoptilum gracile : 1108 : R

Umbellula sp. : 581 : R
Hydrozoa (flat branched) : 56 : R
Annelida
Bonellia viridis : 267 : R
Serpulidae sp. 1 : 106 : R
Serpulidae sp. (black) : 1148 : R
Arthropoda
Galacantha sp. : 1144 : R
Caridea (indet.) : 1077 : R
Colossendeis sp. 1 : 1059 : R
Eucarida sp. : 1106 : R
Eucarida sp. (red deep) : 1138 : R
Mollusca
Margarites sp. 1 : 277 : R
Hypsogastropoda sp. : 621 : R
Polyplacophora sp. : 33 : R
Echinodermata
Bathycrinidae sp. : 1141 : R
Bathycrinidae sp. 1 : 1041 : R
Bathycrinidae sp. 2 cf. Porphyrocrinus thalassae : 1045 : R
Democrinus sp. : 1103 : R
Crinoidea sp. 1 : 131 : R
Ophiomusa lymani : 551 : F
Ophiuroidea (indet.) : 1076 : R
Ophiuroidea sp. 11 (red disc) : 1036 : R
Brisingidae sp. : 274 : R
Stichastrella rosea : 198 : R
Pseudarchaster sp. 1 : 433 : R
cf. Henricia sp. (deep) : 1154 : R

Solaster endeca : 573 : R
Solasteridae sp. (7 arm) : 1061 : R
Solasteridae sp. (white) : 9977 : R
Pterasteridae sp. : 299 : R
Asteroidea sp. : 9992 : R
Asteroidea sp. : 9992 : R
Forcipulatida sp. : 9988 : R
cf. Echinus (deep pink spine) : 1129 : F
Echinidae sp. (pink) : 194 : R
Echinoidea sp. 5 : 572 : R
Benthogone sp. : 432 : R
Benthogone sp. : 432 : R
Benthogone sp. : 432 : R
Mesothuria intestinalis : 536 : R
Oneirophanta mutabilis : 1153 : R
Holothuroidea sp. : 9986 : R
Holothuroidea sp. (muddy) : 1190 : R
Chordata
Nezumia aequalis : 1003 : R
Coryphaenoides guentheri : 577 : R
Macrouridae sp. (cf. Coelorhynchus) : 1172 : R
Macrouridae sp. (cf. Coelorhynchus) : 1172 : R
Lepidion cf. guentheri : 1160 : R
Guttigadus latifrons : 1166 : R
Polyacanthonotus rissoanus : 552 : R

Number of species = 75

© Marine Institute, MERC Consultants, Bernard Picton 2022