D561 Transect PB20 Slope and vertical carbonate wall with scattered sponges, xenophyophores and ophiuroids on mud/gravel/cobble/boulders. Not Priority. Feature: Canyon. Water depth: -1950 m. TL: 1.5 km SOL: 14° 45.381' W 50° 52.312' N
Highlights: Bamboo coral Swimming sea cucumber?
Dive begins on soft sandy sediment with barnacle hash. In areas this barnacle harsh aggregates to create large waves. Occasional xenophyopores, ophiuroids and echinoid urchins are seen among the barnacle hash. A large carbonate wall is observed on this dive, species poor with individual Chrysogorgiidae sp. and encrusting sponges along the wall. Towards the end of the dive there are well distributed clumps of Solenosmilla variabilis.
START VIDEO [00:00:00]/12:49. [1] Epifaunally sparse rippled sand sea floor. [00:01:00] ROV still at the bottom sampling 2 pushcores. Sand and gravel. Sparse epifauna. [00:09:00] Mud cloud/vision obscured briefly. [00:16:00] Infrequent carbonate cobbles/small boulders. [00:13:00] [2] Ophiomusa lymani OTU55 on rippled sand and gravel sediment. [00:18:00] [3] Here Chrysogorgiidae sp. OTU1008 frequently encountered on carbonate bedrock, and O. lymani on sand. [00:19:00] ROV moves forward and upwards. Here vertical carbonate wall with inlets. Chrysogorgiidae sp. and O. lymani co-dominate. [00:29:00] [4] ROV reaches the summit of the carbonate wall where sediment becomes rippled sand and gravel on gentle upslope. Here S. fragilissima OTU261 and O. lymani co-dominate. Scattered boulders host Caryophyllia OTU6 and encrusting sponges OTU1. [00:30:00] ROV stops for imagery of possible jellyfish (to be confirmed). [00:50:00] [5] Here sloping carbonate bedrock with sparse sponges. [00:51:00] [6] Now muddy sediment with frequent O. lymani and sea urchins OTU1129. Fluffy matter on sand. [00:53:00] [7] Sand sediment with scattered pebbles/cobbles on gently upslope. Frequent encounters of Geodia cf. barretti OTU601 on rock. [01:00:00] [8] Solenosmilia variabilis colonies on boulder. Mostly dead reef. Yellow encrusting sponge sp. 15 OTU58 on bedrock. [01:03:00] ROV stops for imagery of S. variabilis colonies on boulder. [01:04:00] [9] Muddy sediment with fluffy matter and scattered cobbles. END VIDEO [01:10:30]/14:00.
Progression | Start | Duration | Code | Name |
---|---|---|---|---|
1 | [00:00:00] | 00:14:24 | M.AtLB.Sa | Atlantic lower bathyal sand |
2 | [00:14:25] | 00:04:27 | M.AtLB.Sa | Atlantic lower bathyal sand |
3 | [00:18:53] | 00:11:23 | M.AtLB.Ro | Atlantic lower bathyal rock and hard substrata |
4 | [00:30:17] | 00:23:54 | M.AtLB.Sa | Atlantic lower bathyal sand |
5 | [00:54:12] | 00:01:17 | M.AtLB.Ro | Atlantic lower bathyal rock and hard substrata |
6 | [00:55:30] | 00:03:29 | M.AtLB.Mu | Atlantic lower bathyal mud |
7 | [00:59:00] | 00:04:38 | M.AtLB.Ro.MixCor.DisSol | Discrete Solenosmilia variabilis colonies on Atlantic lower bathyal rock and other hard substrata |
8 | [01:03:39] | 00:06:55 | M.AtLB.Mu | Atlantic lower bathyal mud |
Foraminifera
Syringammina fragilissima : 261 : R
Porifera
Geodia cf. atlantica (Porifera massive lobose sp. 6) : 83 : R
cf. Geodia baretti (Porifera massive globose sp. 11) : 601 : R
Porifera encrusting sp. 15 (yellow) : 58 : R
Porifera globose (muddy) : 1128 : R
Blue Porifera encrusting : 800 : R
Cnidaria
Cerianthidae sp. 1 : 2 : R
Actiniaria sp. 20 : 605 : R
Actinostolidae sp. 1 : 132 : R
Adamsia sp. : 1066 : R
Bathypathes sp. 1 : 328 : R
Caryophyllia sp. 2 : 6 : R
Solenosmilia variabilis : 700 : R
Anthomastus grandiflorus : 278 : R
Chrysogorgidae sp. 1 : 1008 : R
Acanella arbuscula : 585 : R
Paramuricea sp. : 1050 : R
Pennatulacea sp. 3 (submerged axis) : 1191 : R
Pennatula cf. inflata : 1083 : R
Hydrozoa (flat branched) : 56 : R
Arthropoda
Paguridae sp. : 205 : R
Eucarida sp. (red deep) : 1138 : R
Mollusca
Hypsogastropoda sp. : 621 : R
Echinodermata
Pentametrocrinus atlanticus : 436 : R
Euryalida sp. : 1307 : R
Ophiomusa lymani : 551 : O
Stichastrella rosea : 198 : R
Solaster endeca : 573 : R
Solasteridae sp. (white) : 9977 : R
cf. Echinus (deep pink spine) : 1129 : O
Mesothuria intestinalis : 536 : R
Chordata
Chimaera opalescens : 653 : R
Synaphobranchus kaupii : 440 : R
Coryphaenoides guentheri : 577 : R
Polyacanthonotus rissoanus : 552 : R
Actinopterygii sp. 3 : 930 : R
Number of species = 36
© Marine Institute, MERC Consultants, Bernard Picton 2022