Marine Institute
SeaRover Dive Video

D656 Transect 45 Stalked epifauna on muddy slope with occasional boulders hosting encrusted fauna and bivalves/ascidians on carbonate scarp. P1. Water depth: 1393m. Features: Ridge

Highlights: Plastic litter Plastic litter & fishing net Plastic litter Dumbo octopus - Grimpoteuthis Plastic litter, fishing line & broken bamboo coral Fishing net, broken bamboo coral Brisingid starfish Hexactinellid sponge - Hyalonema Sea pen - Umbellula Fishing line

Of note: Bamboo coral stalks, marine litter, fishing line and net.

Seafloor is initially soft, sandy sediment. Boulders, large basalt rocks and carbonate terraces are present towards the end of the dive. Bare stalks of bamboo corals are present on these rocks. Sea pens and cerianthids are abundant with evidence of coral rubble. Occasional Hyalonema sponges, stalked crinoids and the octocoral Umbellula sp. are observed. A Hyalonema specimen (with zooanthids on its stalk) and a large Anthomastus sp. were sampled.

START VIDEO [00:00:00]/13:46. Stalked epifauna on muddy slope with occasional boulders hosting encrusted fauna and bivalves/ascidians on carbonate scarp. [1] the dive starts on muddy slope with seapens, cerianthids and soft Acanella arbuscula. [00:01:00] ROV lands on mud slope, then hits the sea floor and vision is obscured/mud cloud. [00:03:00] ROV stops for sampling two pushcores (A and ?). [00:14:00] Orange Roughy observed here. [00:24:00] [2] Mud and boulders hosting encrusting sponges and anemones. [00:26:00] [3] Now biotope changes into soft sediment with no dominant epifauna. Rubbish (grey plastic sheet). [00:33:00] [4] Mud and carbonate substrata host various epifauna including lamellate sponges, soft corals and anemones. [00:34:00] Here carbonate boulder hosts lamellate sponges, crinoids and octocorals. Next to the boulder, a pile of fishing gear and rubbish encountered. [00:36:00] [5] Here sediments are mud and gravel with anemones and crinoids. [00:39:00] Poor vision, obscured. [00:44:00] rubbish. [00:49:00] [6] Biotope changes in mud and boulders hosting solitary scleractinians and Pliobrothus sp. . [00:58:00] Good quality zoomed-in images of Pseudoanthomastus sp. . ROV stops for sampling Pseudoanthomastus. [01:08:00] fishing gear. [01:10:00] Obscured vision/mud cloud . [01:12:00] [7] Now mud/gravel and cobbles dominate. Epifauna comprise crinoids and holothurians. [01:13:00] rubbish. [01:16:00] [8] Mud/gravel and mud veneered carbonate hosting crinoids and solitary scleractinians. [01:20:00] [9] Carbonate and mud are the dominant substrata, with ascidians and mixed corals living on rock. [01:27:00] ROV stops for imagery and sampling of Hyalonema sp. . [01:34:00] [10] Biotope is mainly mud with scattered boulders hosting seapens, stalked sponges, encrusting sponges and A. arbuscula. END VIDEO [02:05:00]/15:30.

Progression Start Duration Code Name
1[00:00:00]00:24:21M.AtMB.MuAtlantic mid bathyal mud
2[00:24:22]00:01:47M.AtMB.MuAtlantic mid bathyal mud
3[00:26:10]00:07:15M.AtMB.MuAtlantic mid bathyal mud
4[00:33:26]00:02:43M.AtMB.MuAtlantic mid bathyal mud
5[00:36:10]00:13:34M.AtMB.MuAtlantic mid bathyal mud
6[00:49:45]00:22:26M.AtMB.MuAtlantic mid bathyal mud
7[01:12:12]00:04:18M.AtMB.MuAtlantic mid bathyal mud
8[01:16:31]00:04:11M.AtMB.MuAtlantic mid bathyal mud
9[01:20:43]00:02:27M.AtMB.RoAtlantic mid bathyal rock and other hard substrata
10[01:23:11]00:42:08M.AtMB.MuAtlantic mid bathyal mud

Porifera
Hyalonema sp. 1 : 917 : R
Porifera encrusting sp. 1 (white) : 1 : R
Porifera encrusting sp. 2 : 7 : R
Porifera lamellate sp. 13 : 1053 : R
Cnidaria
Cerianthidae sp. 1 : 2 : F
Actiniaria sp. 20 : 605 : O
cf. Halcampoididae sp. : 984 : O
Actinoscyphiidae sp. 1 (pink) : 1047 : R
Actinostolidae sp. 1 : 132 : R
Phelliactis sp. 1 : 255 : R
Corallimorphidae sp. 1 : 39 : O
Caryophyllia sp. 2 : 6 : R
Caryophyllia sp. 5 (bullseye) : 584 : R
Acanthogorgia cf. armata : 608 : R
Anthomastus grandiflorus : 278 : R
Pseudoanthomastus sp. : 1080 : R
Anthothela grandiflora : 311 : R
Metallogorgia/Iridogorgia or Cirripathes : 994 : R
cf. Clavulariidae sp. : 289 : R
Acanella arbuscula : 585 : R

Paramuricea sp. : 1050 : R
Swiftia sp. : 661 : R
Pennatulacea (indet.) : 1114 : R
Halipteris cf. finmarchica : 622 : R
Kophobelemnon stelliferum : 442 : R
Pennatula aculeata : 1046 : F
Pennatula inflata : 1183 : R
Umbellula sp. : 581 : R
Pliobothrus sp. : 207 : R
Arthropoda
Munida tenuimana : 339 : R
Caridea (indet.) : 1077 : R
Mollusca
Opisthoteuthis extensa : 918 : R
Teuthida sp. 1 : 1017 : R
Hypsogastropoda sp. : 621 : R
Echinodermata
Bathycrinidae sp. : 1141 : R
Pentametrocrinus atlanticus : 436 : R
Crinoidea sp. 1 : 131 : F
Ophiuroidea sp. 1 : 26 : R
Novodinia sp. : 1087 : R

Stichastrella rosea : 198 : O
Echinidae sp. (white) : 559 : R
Cidaris cidaris : 211 : R
cf. Histocidaris purpurata (deep) : 1092 : R
Benthogone sp. : 432 : R
Holothuroidea sp. (pink deep) : 1179 : R
Chordata
Ascidiacea sp. 2 : 20 : R
Rajiformes sp. 1 (Neoraja caerulea?) : 652 : R
Hydrolagus cf. affinis : 1039 : R
Synaphobranchus kaupii : 440 : O
Ipnopidae sp. : 1078 : R
Hoplostethus atlantica : 651 : R
Trachyrincus sp. : 446 : R
Macrouridae sp. (cf. Coelorhynchus) : 1172 : R
Lepidion eques : 249 : R
Polyacanthonotus rissoanus : 552 : R
Neocyttus helgae : 563 : R

Number of species = 56

© Marine Institute, MERC Consultants, Bernard Picton 2022