Marine Institute
SeaRover Dive Video

D678 Transect 51 Muddy slope with variant dominant species. Mainly cup coral and sea cucumber fields. P1. Water depth: 1421 m. Feature: Muddy moderate to steep slope throughout.

Highlights: Cup coral field Purple sea cucumber Bamboo coral Sea cucumber

Initially fauna is sparse, mainly grenadiers and eels. An extensive field of cup corals and later holothurians are abundant on the muddy slope. On soft sediment numerous burrows with a variety of holothurians species and the occasional Mesothuria sp. are noted. Various sea pens and a bamboo coral also evident on sediment. Anemones include cerianthids, cup corals, and the smooth variety of Phelliactis sp.

START VIDEO A [00:00:00]/05:37. Muddy moderate to steep slope with scattered epifauna. Remarkable holothurian aggregations encountered. [1] The entire dive is set on muddy slope with variant dominant species. Mainly cup coral and sea cucumber fields. ROV samples two pushcores. [00:11:00] animal tracks. [00:24:00] animal tracks. [00:29:00] Here rubbish hosts a colony of corals, however, identification is not possible due to poor visibility. Therefore, only rubbish at this site recorded. [00:35:00] Now cup coral fields (unknown species) with scattered sea pens found on moderate muddy slope. [01:00:00] Here cup corals become less abundant, and Acanella arbuscula fields become more abundant. [01:28:00] from this point Holothuroidea cf. Laetmogone co-habits with Pentametrocrinus atlanticus and A. arbuscula until END VIDEO 07:33. START VIDEO B [02:03:47]/07:43. The second dive shows similar biotopes as in video A. Predominantly sea cucumbers, P. atlanticus and A. arbuscula on muddy slope. [02:24:30] the ROV goes slightly backwards and then stops until END VIDEO [02:25:39]/08:01.

Progression Start Duration Code Name
1[00:00:00]00:35:46M.AtLB.MuAtlantic lower bathyal mud
2[00:35:47]00:24:29M.AtLB.Mu.SolSclSolitary scleractinian field on Atlantic lower bathyal mud
3[01:00:17]00:28:39M.AtLB.Mu.EreCor.AcaArbAcanella arbuscula assemblage on Atlantic lower bathyal mud

Foraminifera
Syringammina fragilissima : 261 : R
Cnidaria
Cerianthidae sp. 1 : 2 : R
Pachycerianthus multiplicatus : 458 : R
Actiniaria sp. 1 : 4 : R
Actiniaria sp. 18 : 582 : O
Actiniaria sp. 20 : 605 : R
Bolocera tuediae : 12 : R
Actinauge richardi : 499 : R
Phelliactis sp. 1 : 255 : R
Caryophyllia sp. 2 : 6 : A
Flabellum sp. : 1056 : R
Metallogorgia/Iridogorgia or Cirripathes : 994 : R
Acanella arbuscula : 585 : R
cf. Halipteris sp. : 1060 : R
Pennatulacea sp. 3 (submerged axis) : 1191 : R
Pennatulacea sp. 6 : 1196 : R
Halipteris cf. finmarchica : 622 : R
Kophobelemnon stelliferum : 442 : O
Arthropoda

Caridea (indet.) : 1077 : R
Caridea (indet.) : 1077 : R
Mollusca
Opisthoteuthis extensa : 918 : R
Teuthida sp. 1 : 1017 : R
Hypsogastropoda sp. : 621 : R
Echinodermata
Pentametrocrinus atlanticus : 436 : R
Crinoidea sp. 1 : 131 : R
Ophiomusa lymani : 551 : R
Ophiuroidea sp. 10 : 640 : R
Brisingidae sp. : 274 : O
Zoroaster fulgens : 988 : R
Zoroaster fulgens : 988 : O
Pseudarchaster sp. 1 : 433 : R
Porania sp. : 263 : R
Hymenaster cf. pellucidus : 1110 : O
Cidaris cidaris : 211 : R
Phormosoma placenta : 555 : R
cf. Benthogone sp. (white) : 574 : C
Mesothuria intestinalis : 536 : O

Holothuroidea sp. (pink deep) : 1179 : A
Chordata
Leucoraja sp. : 1067 : R
Centrophorus squamosus : 1048 : R
Chimaera monstrosa : 265 : R
Synaphobranchus kaupii : 440 : R
Ipnopidae sp. : 1078 : R
Nezumia aequalis : 1003 : R
Coryphaenoides rupestris : 566 : R
Trachyrincus sp. : 446 : R
Lepidion eques : 249 : R
Mora moro : 349 : R
Polyacanthonotus rissoanus : 552 : R
Notacanthiformes sp. 1 : 1012 : R
Zoarcidae sp. 1 : 259 : R
Neocyttus helgae : 563 : R
Actinopterygii sp. 3 : 930 : R

Number of species = 53

© Marine Institute, MERC Consultants, Bernard Picton 2022