Marine Institute
SeaRover Dive Video

D677 Transect 28 Muddy moderate to steep slope with scattered epifauna. Remarkable holothurian aggregations encountered. P1. Water depth: 1726-1425 m. Feature: Slope, Predicted Pheronema sponge

Highlights: Orange roughy, fishing line Plastic litter Fish Two Neolithodes grimaldi Bullseye cup coral Purple sea urchin Shark White sea cucumber Hexactinellid sponge - Hyalonema

Of note: Aggregates of juvenile holothurians.

Soft sediment, occasional fauna, include eels, grenadiers, holothurians (including Benthogone rosea), orange roughy and Hyalonema sponges. Aggregates of juvenile holothurians observed. Crabs, Lithodes are observed (one carrying another). No Pheronema observed.

START VIDEO [00:00:00]/00:31. The entire video is filmed on muddy moderate to steep slope with scattered epifauna. Remarkable holothurian aggregations encountered. Plenty of rubbish was found in this dive. [00:01:00] ROV stops for sampling two pushcores. [00:08:00] Here, muddy slope is covered with many small organisms including small sea cucumbers (<5 cm long). [00:09:00] Rubbish. [00:33:00] Animal marks on muddy slope. [00:40:00] Very blurred image of Harriotta haeckeli. [00:44:00] Extended aggregation of holothurians with a few Coryphaenoides rupestris swimming around. [00:57:00] ROV hovers on steep muddy slope. [01:47:00] Here a dead crustacean is filmed (poss Neolithodes grimaldii). END VIDEO 02:28. START VIDEO [01:57:00]/02:28. The second video shows the ROV on muddy slope, to validate niskin bottles functionality. [02:15:00] ROV tests niskin bottles (successful). Muddy slope for the entire video with a few Synaphobranchus kaupii and Galeus sp. swimming around the ROV. END VIDEO [02:20:00]/02:52.

Progression Start Duration Code Name
4[00:00:00]00:23:54M.AtLB.MuAtlantic lower bathyal mud
1[00:00:01]23:59:59M.AtLB.MuAtlantic lower bathyal mud
3[00:51:22]01:06:01M.AtLB.MuAtlantic lower bathyal mud

Porifera
Hyalonema sp. 1 : 917 : R
Porifera encrusting sp. 1 (white) : 1 : R
Cnidaria
Cerianthidae sp. 1 : 2 : R
Actiniaria sp. 1 : 4 : R
Actiniaria sp. 20 : 605 : R
Actinauge richardi : 499 : R
Phelliactis sp. 1 : 255 : R
Caryophyllia sp. 5 (bullseye) : 584 : R
Flabellum sp. : 1056 : R
Anthomastus grandiflorus : 278 : R
Annelida
Aphroditidae sp. 1 : 146 : R
Serpulidae sp. 1 : 106 : R
Arthropoda
Neolithodes grimaldii : 1063 : R

Caridea (indet.) : 1077 : R
Mollusca
Hypsogastropoda sp. : 621 : R
Echinodermata
Ophiomusa lymani : 551 : R
Porania sp. : 263 : R
Hygrosoma sp. : 1125 : R
Elpidiidae (indet.) : 1122 : R
Elpidiidae sp. : 1116 : A
Benthogone sp. : 432 : O
Chordata
Galeus sp. : 1305 : R
Centrophorus squamosus : 1048 : R
Squaliformes sp. : 569 : R
Chimaera opalescens : 653 : R
Harriotta raleighana : 936 : R
Synaphobranchus kaupii : 440 : R

Hoplostethus atlantica : 651 : R
Coryphaenoides guentheri : 577 : R
Coryphaenoides rupestris : 566 : R
Trachyrincus sp. : 446 : R
Trachyrincus sp. : 446 : R
Antimora sp. : 1301 : R
Polyacanthonotus rissoanus : 552 : R
Notacanthiformes sp. 1 : 1012 : R
Cataetyx laticeps : 1111 : R
cf. Rouleina attrita : 1074 : R
Zoarcidae sp. 1 : 259 : R
Neocyttus helgae : 563 : R
Actinopterygii sp. 3 : 930 : R

Number of species = 40

© Marine Institute, MERC Consultants, Bernard Picton 2022