Marine Institute
SeaRover Dive Video

D497 Transect 52 Extensive dead Lophelia carbonate mound with trawled though probably naturally dead reefs. Small patches with mature Jasonisis sp. present. Features: Predicted Pheronema aggregations and Lophelia reef Water Depth: 1099-899 m

Highlights: Demosponge - Cliona sp. Fish on Lophelia Antipatharian coral & orange roughy Anglerfish - Lophius piscatorius Crab - Chaceon affinis

Initially the substrate is soft sediment with an abundance of xenophyophores and the bamboo coral, Acanella arbuscula; black coral species Bathypathes sp. and Leiopathes sp. are also present. However, with the exception of a single clump of Madrepora oculata, no living stony coral is observed. A single juvenile Pheronema carpenteri is present at the beginning of the dive. Fish are abundant here with orange roughy, ling and sharks observed. A large amount of dead coral is evident towards the end of the dive.

START VIDEO A [00:00:00]/03:00 [1] (after working with a GoPro for ROV beauty shots) Start at a transition point between an area with cup corals and a boulder into fields of xenophyophores with Acanella arbuscula on mud with rare pebbles. [00:15:00]-[00:28:00] stop for imagery and the sampling of two sponges (one rock boring, and one globose). [00:45:00] increasing pebbles and gravel. [00:47:00] sampling Pheronema carpenteri (only a couple spotted on this dive). [00:57:00] [2] an area of denser pebbles, and sparse protruding bedrock/boulders hosts sparse mixed corals and small lamellate sponges. [00:58:00] [3] return to mud/sand and pebbles with Xenophyophores and Acanella. [01:06:00] increasing coral gravel. [01:15:00] increasing coral rubble (larger chunks) until [01:16:00] [4] mixed corals, sparse at first, including [01:18:51] Paramuricea sp. , a pink sparse-branching gorgonian (OTU307). [01:19:00] sloping carbonate/broken carbonate underlies the coral rubble. [01:20:44] a dense area of Jasonisis sp. [01:23:00] [5] summit of the first carbonate mound covered in even coral rubble/gravel with no visible epifauna, likely trawled. The ROV starts moving downhill with only partial/poor views of seabed. [01:26:00] [6] One brief area of the slope hosts mixed erect corals (Paramuricea sp . & Jasonisis sp . ) on coral rubble. [01:27:00] [7] continuing downhill over coral rubble/gravel, several large Alepocephaliformes (possibly Rouleina attrita) and Chimaera opalescens are lingering here (no dominant epifauna). [01:30:00] [8] Reach saddle area between carbonate mounds. Acanella arbuscula dominates on coral rubble and mud. [01:36:00] [9] xenophyophores on mud/ gravel still some A. arbuscula. [01:43:00] [10] ROV passes over edge of patch with boulders and lamellate sponges and corals, while sand/gravel/shell hash continue to host A. arbuscula. Scattered boulders host a similar community, mosaicked with the coarse sediment until [01:49:00] [11] The coarse sand/gravel and A. arbuscula dominate. Then at [01:57:00] Xenophyophores return, sparse A. arbuscula. END VIDEO A 05:02.

START VIDEO B [02:01:00]/05:03 [13] sparse epifauna on mud/sand [02:05:00] [14] A. arbuscula returns, and several encounters with Orange Roughy (Hoplostethus atlanticus). [02:13:00] increasing coral gravel and rubble indicates the base of the next carbonate mound. [02:16:00] [15] the slope becomes steeper and boulders/cobbles, interspersed with coral gravel, host mixed corals, especially Leiopathes sp . [02:18:00] Carbonate and coral rubble. [02:19:00]-[02:27:00] stop to sample small colony of Madrepora oculata and take imagery. [02:28:00] [16] Dense coral rubble and boulders (one possibly with trawl scrape marks), ophiuroids clearly dominant when up close. [02:32:00] [17] more exposed carbonate with encrusting globose sponges (OTU75) visibly dominant and continued ophiuroids. [02:33:00] strange scratch marks possibly from a trawl. [02:37:00] one small patch with more intact dead framework and a couple of small Lophelia pertusa colonies on broken a carbonate edge (not enough to form a biotope transition). [02:39:00] [18] no more encrusting globose sponges, just sparse epifauna, mainly ophiuroids visible in close ups. [02:40:00] Before reaching the summit the ROV stands heading downhill (with poor views), then at [02:43:00] stops after touching the seabed, and [02:44:00] turns uphill continuing over coral rubble/gravel and carbonate. END VIDEO B 05:55.

Progression Start Duration Code Name
1[00:00:00]00:57:13M.AtMB.Mu.XenCom.SyrFraSyringammina fragilissima field on Atlantic mid bathyal mud
13[00:00:00]02:01:30M.AtMB.MuAtlantic mid bathyal mud
14[00:04:14]00:11:14M.AtMB.Mu.EreCor.AcaArbAcanella arbuscula assemblage on Atlantic mid bathyal mud
15[00:15:29]00:11:48M.AtMB.Ro.MixCorMixed cold water coral community on Atlantic mid bathyal rock and other hard substrata
16[00:27:18]00:03:51M.AtMB.CoAtlantic mid bathyal coarse sediment
17[00:31:10]00:06:57M.AtUB.Ro.DeeSpoDeep sponge aggregation on Atlantic upper bathyal rock and other hard substrata
18[00:38:08]00:14:44M.AtMB.Co.SpaEncSparse encrusting community on Atlantic mid bathyal coarse sediment
2[00:57:14]00:00:40M.AtMB.Ro.MixCorMixed cold water coral community on Atlantic mid bathyal rock and other hard substrata
3[00:57:55]00:08:10M.AtMB.Mu.XenCom.SyrFraSyringammina fragilissima field on Atlantic mid bathyal mud
3[01:06:06]00:10:23M.AtMB.CoAtlantic mid bathyal coarse sediment
4[01:16:30]00:03:52M.AtMB.Co.MixCorMixed cold water coral community on Atlantic mid bathyal coarse sediment
4[01:20:22]00:02:49M.AtMB.Co.MixCorMixed cold water coral community on Atlantic mid bathyal coarse sediment
5[01:23:12]00:03:16M.AtMB.CoAtlantic mid bathyal coarse sediment
6[01:26:29]00:00:23M.AtMB.Co.MixCorMixed cold water coral community on Atlantic mid bathyal coarse sediment
7[01:26:53]00:03:38M.AtMB.CoAtlantic mid bathyal coarse sediment
8[01:30:32]00:05:57M.AtMB.Mu.EreCor.AcaArbAcanella arbuscula assemblage on Atlantic mid bathyal mud
9[01:36:31]00:07:15M.AtMB.Mu.XenCom.SyrFraSyringammina fragilissima field on Atlantic mid bathyal mud
10[01:43:47]00:05:52M.AtMB.Mu.EreCor.AcaArbAcanella arbuscula assemblage on Atlantic mid bathyal mud
11[01:49:40]00:07:59M.AtMB.Mu.EreCor.AcaArbAcanella arbuscula assemblage on Atlantic mid bathyal mud
12[01:57:39]00:03:17M.AtMB.Mu.XenCom.SyrFraSyringammina fragilissima field on Atlantic mid bathyal mud

Unknown mud fluff : 1123 : F
Foraminifera
Syringammina fragilissima : 261 : F
Porifera
Hyalonema sp. 1 : 917 : R
Pheronema carpenteri : 347 : O
Porifera boring sp. 1 : 115 : R
Porifera encrusting (blue) : 532 : R
Porifera encrusting (green) : 13 : R
Porifera encrusting globose (pale) : 75 : F
Porifera encrusting sp. 1 (white) : 1 : R
Porifera encrusting sp. 10 (yellow) : 30 : R
Porifera lamellate sp. 10 : 1010 : R
Porifera lamellate sp. 7 : 422 : O
Porifera lamellate sp. 9 : 606 : R
Porifera massive globose sp. 6 : 137 : R
Porifera massive lobose sp. 30 : 982 : R
Blue Porifera encrusting : 800 : R
Cnidaria
Cerianthidae sp. 1 : 2 : O
Hormathiidae sp. : 1098 : R
Stichopathes sp. : 560 : R
Phanopathes sp. 2 : 1081 : O
Leiopathes sp. : 305 : R
Leiopathes sp. (dense) : 612 : O
Dendrobathypathes ( prev. Stauropathes sp. 1) : 1015 : R
Caryophyllidae/Fabellidae (indet.) : 1058 : O
Lophelia pertusa : 250 : O

Madrepora oculata : 251 : R
Acanthogorgia cf. armata : 608 : O
Anthomastus grandiflorus : 278 : R
Chrysogorgidae sp. 1 : 1008 : R
cf. Clavulariidae sp. : 289 : R
Acanella arbuscula : 585 : F
Eknomisis sp. : 649 : R
Lepidisis sp. : 557 : R
Paramuricea sp. : 1050 : R
Callogorgia verticillata : 280 : R
Gorgonacea sp. (pink, Solenosmilia assoc.) (Jasonisis) : 1070 : O
Gorgonacea sp. 7 (pink) cf. Isidella : 307 : R
Scyphozoa (indet.) : 1134 : R
Annelida
Serpulidae sp. 1 : 106 : R
Arthropoda
Chirostylidae sp. 2 (indet.) : 1054 : R
Chaceon affinis : 254 : O
Munida tenuimana : 339 : R
Caridea (indet.) : 1077 : R
Cirripedia sp. 1 : 82 : R
Mollusca
Octopoda (indet.) : 659 : R
Echinodermata
Brisingidae sp. : 274 : R
Stichastrella rosea : 198 : R
Henricia sanguinolenta : 208 : R
Ceramaster/Peltaster/Plinthaster sp. 2 : 388 : R

Porania sp. : 263 : R
Phormosoma placenta : 555 : R
Echinoidea sp. 1 : 279 : R
cf. Amperima sp. : 628 : R
Chordata
Apristurus sp. (indet.) : 1131 : O
Rajiformes sp. 1 (Neoraja caerulea?) : 652 : R
Squaliformes sp. : 569 : O
Chimaera opalescens : 653 : O
Synaphobranchus kaupii : 440 : R
Hoplostethus atlantica : 651 : O
Brosme brosme : 258 : O
Molva molva : 654 : R
Coelorinchus caelorhincus : 303 : R
Coryphaenoides rupestris : 566 : R
Trachyrincus sp. : 446 : O
Lepidion eques : 249 : F
Mora moro : 349 : O
Lophius piscatorius : 273 : O
Polyacanthonotus rissoanus : 552 : R
cf. Rouleina attrita : 1074 : O
Neocyttus helgae : 563 : O
Actinopterygii sp. 3 : 930 : R
Actinopterygii sp. 4 : 1006 : R

Number of species = 72

© Marine Institute, MERC Consultants, Bernard Picton 2022