Marine Institute
SeaRover Dive Video

D552 Transect PB09 Mud/pebble/carbonate with sparse epifauna. Non Priority. Features: Very Deep wall, Ridge, Canyon. Water depth: -2650 m. TL: 1.8 km SOL: 15° 26.815' W 52° 17.670' N

Highlights: Giant hydroid - Branchiocerianthus Hexactinellid sponge & brisingid starfish

Marine snow visible through dive. Soft rippled sediment with waves of shell hash and large number of elpidiids seen throughout. Rocky outcrops seen occasionally with sponges, gorgonian corals and cup corals with brisingiids attached. Large carbonate wall with mud overlay and black drop stones. The wall is generally species poor with the occasional glass sponges, sea whip and brisingiid. Rippled soft sediment is apparent after the crest of the wall. Species of note included the deepsea lizardfish, Bathysaurus ferox, and the hydroid Branchiocerianthus imperator.

START VIDEO 10:13. [00:00:00]-[00:11:00] ROV samples 2 pushcores. Muddy/pebbles sediment on flat/gentle upslope. Marine snow/suspended sediment present. Holothuroid Peniagone sp. OTU1167 is dominant species. [00:15:00] ROV moves erractically up and down, vision is poor. [00:21:16] ROV stops for imagery of giant hydroid, Branchiocerianthus norvegicus. Vision obscured/mud cloud. [00:31:00] Mud and sand sediment with Peniagone sp. as dominant. Throughout the entire transect, the ROV climbs a moderate steep slope. [00:32:00] ROV touches the seafloor causing mud cloud. Vision obscured. [00:34:00] Vision back to normal. Rippled sand and occasional gravel. Peniagone sp. dominant. [00:37:00] Now carbonate crust and boulders covered in mud with sparse Brisingidae and glass sponges. [00:41:00] Cobbles muddy sediment. [00:42:00] Carbonate crust/boulder with inlets covered in muddy sediment with sparse epifauna. [00:43:00] Now muddy sediment/pebbles and cobbles with occasional epifauna, including Pennatulacea species. [00:46:00] Again carbonate mound/pebbles/mud sediment. Sparse epifauna. [00:51:00] Muddy/pebbles sediment. [01:05:00] Now sand/mud/gravel sediment with occasional epifauna. [01:03:00] ROV goes backwards until END VIDEO [02:00:00]/12:14.

Progression Start Duration Code Name
1[00:00:00]00:33:14M.AtUA.Mu.HolComAtlantic upper abyssal mud, holothurians
2[00:33:14]00:03:21M.AtUA.SaAtlantic upper abyssal sand
3[00:36:36]00:03:41M.AtUA.RoAtlantic upper abyssal rock and other hard substrata
4[00:40:18]00:01:12M.AtUA.RoAtlantic upper abyssal rock and other hard substrata
5[00:41:31]00:01:15M.AtUA.RoAtlantic upper abyssal rock and other hard substrata
6[00:42:47]00:02:35M.AtUA.MuAtlantic upper abyssal mud
7[00:45:23]00:05:30M.AtUA.RoAtlantic upper abyssal rock and other hard substrata
8[00:50:54]00:13:12M.AtUA.SaAtlantic upper abyssal sand
9[01:04:07]00:50:39M.AtUA.MuAtlantic upper abyssal mud
10[01:54:47]00:06:28M.AtUA.MuAtlantic upper abyssal mud

Porifera
Porifera encrusting sp. 1 (white) : 1 : R
Porifera lamellate (bubbles) : 1156 : R
Porifera lamellate lobose : 81 : R
Cnidaria
Actiniaria sp. 18 : 582 : R
Caryophyllia sp. 5 (bullseye) : 584 : R
Anthomastus grandiflorus : 278 : R
Chrysogorgidae sp. 1 : 1008 : R
Acanella arbuscula : 585 : R
Lepidisis sp. : 557 : R
cf. Halipteris sp. : 1060 : R
Pennatulacea sp. 3 (submerged axis) : 1191 : R
Anthoptilum sp. : 1107 : R
Halipteris cf. finmarchica : 622 : R
Umbellula sp. : 581 : R

Corymorphidae sp. : 120 : R
Rhodaliidae sp. 1 : 950 : R
Arthropoda
Chirostylidae sp. 1 (indet.) : 285 : R
Galacantha sp. : 1144 : R
Caridea (indet.) : 1077 : R
Colossendeis sp. 2 : 1201 : R
Echinodermata
Bathycrinidae sp. : 1141 : R
Democrinus sp. : 1103 : R
Anachalypsicrinus nefertiti : 1031 : R
Ophiomusa lymani : 551 : R
Ophiuroidea (indet.) : 1076 : R
Brisingidae sp. : 274 : R
Pseudarchaster sp. 1 : 433 : R
Pterasteridae sp. : 1115 : R

Forcipulatida sp. : 9988 : R
cf. Echinus (deep pink spine) : 1129 : R
Echinothuroidea sp. : 1094 : R
Peniagone sp. : 1167 : R
Mesothuria intestinalis : 536 : R
Chordata
Bathysaurus ferox : 1112 : R
Coryphaenoides guentheri : 577 : R
Macrouridae sp. (cf. Coelorhynchus) : 1172 : R
Polyacanthonotus rissoanus : 552 : R

Number of species = 37

© Marine Institute, MERC Consultants, Bernard Picton 2022