Marine Institute
SeaRover Dive Video

D696 Transect 13 Rich geogenic reefs including mud, pebbles fields and boulders hosting various and abundant epifauna. P3. Water depth: 13331228m. Feature: Interesting bathymetric feature

Highlights: Fishing line entangled on boulder Orange roughy Hexactinellid sponge, Lophelia & Jasonisis Sponges & Solenosmilia

Of Note: Solenosmilia, diverse coral species, orange roughy..

Initially there is a dense bed of polychaete tubes cf. Lanice sp. Solenosmilia and a variety of corals species, including Acanthogoria (a fine branching gorgonian) observed on boulders. Sponges, including Aphrocallistes also present on rocks. The ophiuroid Gorgonocephalus is observed. On soft ground, anemones including cerianthids, Bolocera and Phelliactis are present.

START VIDEO [00:00:00]/10:04. Rich geogenic reefs recorded in this transect. The substrata includes mud, pebbles fields and boulders hosting various and abundant epifauna. This transect hosts the most varied porifera species across all dives (SeaRover 2019). [00:01:00] ROV samples three push cores (the second push core only sampled a small quantity of sediment). [00:02:00] [1] The dive starts with dense fields of polychaete tubes (possibly cf Lanice sp.) on mud. [00:07:00] [2] Here substrata transitions into rippled sand on slope and back again into polychaete tubes fields. [00:14:00] [3] Now substrata changes into mixed sediment of pebbles and mud with scattered epifauna on moderate slope. [00:25:00] [4] Sediment very similar to the previous biotope observed, however, boulders appear frequently and host various encrusting species including barnacles and sea anemones. [00:29:00] ROV slows down for imagery of encrusting species on boulder (e. g. sponges and barnacles). [00:31:00] ROV stops again for imagery of glass sponge (hexactinellid) and Gorgonocephalus. [00:32:00] [5] Here geogenic reefs become more frequent. Boulders host hexactinellid, encrusting sponges and Solenosmilia colonies. [00:33:10] Nylon fishing line tangled on Solenosmilia [00:34:00] ROV stops for imagery of coral gardens and sponge aggregations on boulder. [00:44:00] ROV stops for imagery of coral and sponge geogenic reef. [00:47:00] ROV circumnavigate a large boulder twice (clock- and anticlockwise). This footage could be potentially used for photogrammetry. [00:58:00] fishing net. [00:57:00] [6] Pebble fields interspersed with boulders hosting encrusting species on moderate slope. [01:25:00] [7] Coral and sponge geogenic reef with abundant Aphrocallistes sp. . [01:26:00] Rubbish wrapped around an individual of Paramuricea placomus. [01:37:00] Pebbles interspersed with boulders on moderate slope with abundant epifauna. VIDEO END [01:57:00]/12:00.

Progression Start Duration Code Name

Foraminifera
Syringammina fragilissima : 261 : R
Porifera
Asconema sp. (Porifera massive globose 14) : 650 : R
Aphrocallistes beatrix : 264 : O
cf. Phakellia ventilabrum : 202 : R
Stryphnus fortis : 657 : R
Hexadella dedritifera : 658 : R
Porifera cup 2 : 535 : R
Porifera cup sp. 3 : 124 : R
Porifera encrusting sp. 1 (white) : 1 : R
Porifera encrusting sp. 15 (yellow) : 58 : R
Porifera encrusting sp. 2 : 7 : R
Porifera encrusting sp. 9 : 21 : R
Porifera encrusting white (unknown) : 1315 : R
Porifera lamellate (Hexactinosida) : 1151 : R
Porifera lamellate sp. 13 : 1053 : R
Porifera massive lobose sp. 32 : 1090 : R
Cnidaria
Cerianthidae sp. 1 : 2 : R
Pachycerianthus multiplicatus : 458 : R
Actiniaria sp. (large red) : 1120 : R
Actiniaria sp. 13 (pink/purple) : 478 : R
Actiniaria sp. 18 : 582 : R
Actiniaria sp. 18 : 582 : R
Actiniaria sp. 20 : 605 : R
cf. Halcampoididae sp. : 984 : R
Sagartidae sp. (wide oral disc) : 1118 : R
Adamsia sp. : 1066 : R
Phelliactis sp. 1 : 255 : R
Corallimorphidae sp. 1 : 39 : R

Caryophyllia sp. 2 : 6 : R
Desmophyllum cf. dianthus : 335 : R
Solenosmilia variabilis : 700 : F
Flabellum sp. : 1056 : R
Epizoanthus sp. 1 (Paguridae associated) : 317 : R
Acanthogorgia cf. armata : 608 : O
Anthothela grandiflora : 311 : R
cf. Clavulariidae sp. : 289 : R
Acanella arbuscula : 585 : R
Isididae sp. (fine branching) : 1064 : R
Paramuricea sp. : 1050 : R
Pennatula aculeata : 1046 : R
Umbellula sp. : 581 : R
Pliobothrus sp. : 207 : O
Annelida
Serpulidae sp. 1 : 106 : R
Annelida sp. 5 : 967 : A
Arthropoda
Majidae sp. 1 : 11 : R
Munida tenuimana : 339 : R
Paguridae sp. : 205 : R
Caridea (indet.) : 1077 : R
Munidopsis sp. : 1126 : R
Colossendeis sp. 1 : 1059 : R
Cirripedia sp. 1 : 82 : R
Mollusca
Graneledone sp. 1 : 937 : R
Brachiopoda
Brachiopoda sp. 1 : 34 : F
Mollusca
Hypsogastropoda sp. : 621 : R

Echinodermata
Pentametrocrinus atlanticus : 436 : R
Ophiactis abyssicola : 100 : R
Ophiactis abyssicola : 100 : R
Gorgonocephalus sp. 1 : 214 : R
Brisingidae sp. : 274 : R
Zoroaster fulgens : 988 : R
Pseudarchaster sp. 1 : 433 : R
Porania sp. : 263 : R
Pterasteridae sp. : 299 : R
Pterasteridae sp. : 1115 : R
Echinus sp. : 445 : R
Cidaris cidaris : 211 : R
cf. Psolus sp. : 1049 : R
Holothuroidea sp. (pink deep) : 1179 : R
Chordata
Ascidiacea sp. 2 : 20 : R
Galeus sp. : 1305 : R
Rajidae sp. 2 : 382 : R
Hydrolagus cf. mirabilis : 1024 : R
Synaphobranchus kaupii : 440 : R
Ipnopidae sp. : 1078 : R
Hoplostethus atlantica : 651 : R
Coryphaenoides rupestris : 566 : R
Trachyrincus sp. : 446 : R
Lepidion eques : 249 : R
Guttigadus latifrons : 1166 : R
Polyacanthonotus rissoanus : 552 : R
Notacanthiformes sp. 1 : 1012 : R
Neocyttus helgae : 563 : R

Number of species = 82

© Marine Institute, MERC Consultants, Bernard Picton 2022