Marine Institute
SeaRover Dive Video

D535A Transect RB08 cobble/boulder/coral framework/carbonate cliff. Biogenic and geogenic Solenosmilia reefs. Priority 1. Features: Wall, Escarpment, 2009, SAC. Water depth: -1670 m. TL: 1km. SOL: 14° 32.766' W 55° 54.736' N

Highlights: Anemone Fish Chimaera Acesta excavata file shell & Solenosmilia Sea fans

On soft sediment at the beginning of the dive cup corals, cerianthids, eels and grenadiers occur. This transitioned to more broken hard ground with small soft corals are evident and the occasional clump of Solenosmilia. While ascending a hard incline fauna is initially scarce but continuing up slope coral rubble and living Solenosmilia become more common and form an extensive reef. Brisingiids, Leiopathes sp., Acanella sp., Parantipathes sp. are all evident along with associated fauna, sponges and fish. The oyster Acesta excavata is abundant. Over the top of a wall the ground is again soft sediment with occasional Stichopathes sp., ophiuroids and cup corals.

START VIDEO [00:00:00]/19:05 Bedrock and mud with sparse epifauna including Ophiuroidea and anemones on a gentle down slope. Suspended mud. [00:03:00] The ROV moves up and down along the water column. Poor visibility. [00:05:00] Visibility back to normal, although ROV escapes from mud clouds. [00:07:00] Here carbonate mounds and crusts with scarce visible epifauna. [00:08:00] ROV hovers close to a carbonate boulder, which reveals a field of sea pens. [00:09:00] Poor visibility. [00:10:00] The ROV reaches the edge of the carbonate boulder and descends on a flat/slightly down hill muddy sediment with carbonate boulders with scarce epifauna. Holothuroidea species and Ophiomusa lymani dominate. [00:13:00] Frequent cobbles and carbonate boulders in this part of the transect. O. lymani dominates. [00:15:00] substrata changes into boulders, coral framework (mainly dead reef) and mud with sparse epifauna. [00:17:00] Now substrata intersperse between mud/cobbles and bedrock/mud. Epifaunally scarce. Visibility at times poor as ROV hovers high on the ground. [00:19:00] Steep bedrock with overhanging antipatharians and Solenosmilia variabilis reefs (living and dead). [19:27:00] ROV reaches the summit. [00:22:00]-[00:23:00] Blue water for a minute while ROV descends the steep carbonate cliff. [00:25:00] Visibility is clear again and ROV moves along the cliff. Sparse epifauna with a few individual of Coryphaenoides species. [00:26:00] the ROV gets closer to the ground showing O. lymani and Stichopathes sp. [00:26:00] ROV stops for imagery and hits the carbonate mound. Mud obscures the video for a few seconds. ROV moves upwards to escape the muddy cloud. [00:27:00]-[00:32:00] ROV stops for imagery and carbonate cobble sampling. [00:34:00] ROV climbs steep carbonate cliff with dominant Ceriantharia sp. [00:41:00] Coral reef framework (100% dead) on carbonate mound. [00:44:00] A few dead bivalvia (poss Acesta excavata). [00:55:00] ROV reaches the summit. Coral reef framework (living and dead) persists with abundant sponge aggregations. [01:00:00] No more coral reef framework, now muddy sediment with sparse cobbles. [01:03:00] Sampling of cobble with Cirripedia sp. and Anthomastus grandiflorus as well as 1 pushcore until END VIDEO [01:11:00]/20:16.

Progression Start Duration Code Name
1[00:00:00]00:18:42M.AtLB.RoAtlantic lower bathyal rock and hard substrata
2[00:18:43]00:01:59M.AtLB.Ro.MixCor.DisSolDiscrete Solenosmilia variabilis colonies on Atlantic lower bathyal rock and other hard substrata
3[00:20:43]00:18:23M.AtLB.RoAtlantic lower bathyal rock and hard substrata
4[00:39:07]00:03:10M.AtLB.Ro.MixCor.DisSolDiscrete Solenosmilia variabilis colonies on Atlantic lower bathyal rock and other hard substrata
5[00:42:18]00:01:42M.AtLB.Bi.CorRee.SolFraMixed coral assemblage on Atlantic lower bathyal Solenosmilia reef framework (biogenic structure)
6[00:44:01]00:03:14M.AtLB.Ro.MixCorMixed cold water coral community on Atlantic lower bathyal coarse sediment
7[00:47:16]00:01:44M.AtLB.Bi.CorRee.SolFraMixed coral assemblage on Atlantic lower bathyal Solenosmilia reef framework (biogenic structure)
8[00:49:01]00:05:13M.AtLB.Bi.CorRee.SolFraMixed coral assemblage on Atlantic lower bathyal Solenosmilia reef framework (biogenic structure)
9[00:54:15]00:05:16M.AtLB.Bi.CorRee.SolFraMixed coral assemblage on Atlantic lower bathyal Solenosmilia reef framework (biogenic structure)
10[00:59:32]00:11:32M.AtLB.MuAtlantic lower bathyal mud

Porifera
cf. Phakellia ventilabrum : 202 : R
Mycale lingua : 171 : O
cf. Geodia baretti (Porifera massive globose sp. 11) : 601 : R
Porifera cylindrical sp. 2 : 1075 : R
Porifera encrusting (green) : 13 : R
Porifera lamellate sp. 10 (Yellow Solenosmilia assoc.) : 623 : R
Porifera lamellate sp. 9 : 606 : O
Porifera massive globose sp. 6 : 137 : R
Blue Porifera encrusting : 800 : R
Cnidaria
Cerianthidae sp. 1 : 2 : R
Actiniaria sp. 13 (pink/purple) : 478 : R
Actiniaria sp. 20 : 605 : R
Actiniaria sp. 21 : 900 : R
cf. Halcampoididae sp. : 984 : R
Actinernus michaelsarsi : 554 : R
Bolocera tuediae : 12 : R
Actinostolidae sp. 1 : 132 : R
Liponema sp. : 1055 : R
Stichopathes sp. : 560 : R
Leiopathes sp. : 305 : R

Bathypathes sp. (brown) : 284 : R
Parantipathes sp. : 1042 : R
Caryophyllia sp. 2 : 6 : R
Solenosmilia variabilis : 700 : R
Zoanthidea sp. : 1149 : R
Anthomastus grandiflorus : 278 : R
Acanella arbuscula : 585 : R
Eknomisis sp. : 649 : R
Keratoisis sp. (fine branching) : 1157 : R
Paragorgia (twiggy) (poss. Swiftia) : 1065 : R
Pennatulacea (indet.) : 1114 : R
Pennatula aculeata : 1046 : R
Arthropoda
Caridea (indet.) : 1077 : R
Mollusca
Acesta excavata : 1062 : R
Sepiolidae sp. : 1095 : R
Echinodermata
Pentametrocrinus atlanticus : 436 : R
Crinoidea sp. : 1072 : R
Crinoidea sp. 1 : 131 : R
Ophiomusa lymani : 551 : R

Brisingidae sp. : 274 : R
Henricia sanguinolenta : 208 : R
Solaster endeca : 573 : R
Pterasteridae sp. : 299 : R
Echinus sp. (deep, white/pink) : 1052 : R
Benthogone sp. : 432 : O
Benthogone sp. : 432 : R
Psychropotes depressa : 1169 : R
Mesothuria intestinalis : 536 : R
Chordata
Ascidiacea sp. 2 : 20 : R
Chimaera opalescens : 653 : R
Coryphaenoides guentheri : 577 : R
Coryphaenoides rupestris : 566 : R
Guttigadus latifrons : 1166 : R
Polyacanthonotus rissoanus : 552 : R
Notacanthiformes sp. 1 : 1012 : R
Neocyttus helgae : 563 : R

Number of species = 56

© Marine Institute, MERC Consultants, Bernard Picton 2022