Marine Institute
SeaRover Dive Video

D496 Transect 41 Mixed sloping/vertical rock types with stalked crinoids and mature erect corals, some giant boulders/bedrock protrusions with Solenosmilia colonies and rubble aprons. Features of interest: canyon, escarpment Water Depth: 1911-1400 m

Highlights: Fish Chimaera Bamboo coral Boulder with sponges & crinoids Demosponge Antipatharian coral Sea fan

The sediment of the canyon floor is soft and the fauna consists of anemones, echinoids, holothurians and fish. Along slope soft sediment gives way to large stones and boulders with anemones, black coral, sponges, crinoids and starfish. Rich diversity of fauna is present on all hard substrates.

Coral species include Bathypathes sp., Leiopathes sp., Parantipathes sp., and Gorgonacea sp. Further up slope sharp rocky outcrops are colonised by large coral specimens. The bedrock rises steeply to form vertical walls colonised by numerous sponge species, the corals Stichopathes sp. and Lepidisis sp., crinoids and anemones including hormathiid anemones. The sea pen, Distichoptilum gracile, normally seen on soft ground is also present here. A sheer 100 m vertical cliff wall contains Solenosmilia variabilis coral rubble but no evidence of living reef. Overall S. variabilis is very common throughout this site. Evidence of variable underwater currents is noted through this site.

START VIDEO A [00:00:00]/18:49 [1] mud with small thin sea pens that are hard to identify (OTU1083, possibly small Distichoptilum sp?). ROV moving left, [00:01:00] right, encounter colonised plastic bottle, [00:03:00] moving straight ahead. [00:19:00] [2] the sea pens continue but patches of exposed sloping and vertical terraced carbonate host mixed corals, especially Stauropathes arctica. [00:29:00] [3] while similar terraced carbonate and corals are present, stalked crinoids are now abundant and dominate the hard substrate epifauna, Stichopathes sp. (OTU560) is often abundant. [00:34:00] drop stones and pebbles start being encountered, these are atop of the carbonate and its mud veneer, and have a slightly different community to the carbonate, with serpulids and lobose sponges (cf. Geodia, OTU83) being especially abundant along with stalked crinoids and mixed corals. All of these communities and substrates are present and mosaicked as we continue upslope. [00:34:00]-[00:36:00] stopped to image dropstone, [00:41:00] moving right along slope. [00:43:00]-[00:44:00] imaging dropstone. [00:45:00]-[00:47:00] imaging Leiopathes sp. [00:48:00]-[00:49:00] imaging Radicipes cf. gracilis, [00:50:00]-[00:51:00] imaging dropstones and Leiopathes. [00:52:00] ROV moving forward upslope, [00:54:00] ROV moving left. [00:55:00] [4] the beginning of areas of denser cobbles and boulders overlaying the carbonate and mud veneer, the seapen biotope is no longer present. Stichopathes sp. , Bathycrinidae sp . and the lobose sponges (OTU83) remain dominant. [01:05:00]-[01:06:00] some coral rubble present at the bease of a carbonate outcropping and a couple of Solenosmilia variabilis colonies are still live as discrete colonies on the rock face. [01:08:00]-[01:10:00] imaging Leiopathes. Moving left, [01:11:00] forward upslope. [01:11:46] cliff face displays transition from carbonate to black bedrock. [01:12:00] moving left along cliff face of bedrock, again serpulids and sponges are abundant amongst the other fauna. [01:12:00] moving slow with several stops to image large sponges. [01:14:00] top of cliff visible, Stichopathes sp. are abundant on the top surface along with a Radicipes cf. gracilis. [01:15:00] moving left along cliff edge and slightly down cliff face. [01:20:00]-[01:29:00] stopped to sample cf. Geodia barretti (OTU601) then move left along shelf/cliff face. [01:32:00] ascend and head upslope. [01:36:00] [5] mud now dominates, although is sometimes only a thin veneer over underlying bedrock. Cobbles and boulders carry the majority of fauna, continuing the mixed corals and stalked crinoid community. [01:48:15] [6] mud with rare cobbles boulders, although some epifauna are present there are no clear dominant species. END VIDEO A 20:49.

START VIDEO B [01:59:00]/20:50. [02:04:00] ROV now too high. [02:05:00] [7] mud and pebbles with scattered/patchy boulders, too high to see dominant fauna. [02:06:00] moving diagonally right. [02:07:00] [8] find dead coral (Solenosmilia variabilis) rubble apron on carbonate slope and start moving upslope . [02:08:00] [9] meet bedrock feature with discrete Solenosmilia variabilis colonies on vertical faces and move left around and up, finding mature erect corals on the summit, especially Lepidisis sp. among others. Proceed over summit, [02:14:00] [10] descend otherside (brief blue water) meeting mud downslope and heading along slope, meeting rare small boulders. [02:22:00]-[02:23:00] stopped to image Aphroditidae sp. [02:25:00] [11] meet large boulder/outcropping and circle. It again hosts Solenosmilia variabilis and large erect corals with coral rubble around the base. [02:30:00] [12] turn back along transect and proceed (blue water briefly) back over mud slope with occasional boulders (slight deviations to look at boulders). [02:41:00]-[02:42:00] stopped to image sponge. [02:45:00] many juvenile Hoplostethus atlanticus are encountered on this mud slope. Transition along and upslope. [02:59:00] [13] beginning of coral rubble apron, angle further upslope over coral rubble. [03:01:00] moving right along and slightly upslope. [03:04:00] [14] Meet bedrock outcroppings, well colonised by discrete Solenosmilia variabilis colonies and Acesta excavata clams. [01:10:00] [15] another rubble apron, [03:09:00]-[03:10:00] stopped to image octopus. [03:10:00] [16] again bedrock with S. variabilis on vertical faces. [03:12:00] [17] mud and pebble slope with Ophiomusa lymani and bedrock outcroppings with mixed corals especially Stichopathes sp. [03:14:00] [18] rubble apron. [03:16:00] [19] bedrock outcrop with S. variabilis and mature erect corals (e. g. Jasonisis sp . ) and sponges especially on the top ledge. Track along ledge edge. [03:21:00]-[03:23:00] Imaging Keratoisis sp. [03:22:00] [20] mud with sparse pebbles, no dominant fauna, and sporadic bedrock protrusions with continued mixed corals and sponges. [01:24:00] [21] mud with sparse pebbles and Acanella arbuscula. [03:24:00] ROV too high, 03:025-[03:26:00] canít see bottom, only blue water. [03:26:00] back on bottom until END VIDEO B [03:28:00]/22:19.

Progression Start Duration Code Name
1[00:00:00]00:19:07M.AtMB.Mu.SpnMegSea pens and burrowing megafauna on Atlantic mid bathyal mud
6[00:00:00]01:59:45M.AtLB.MuAtlantic lower bathyal mud
7[00:06:04]00:02:47M.AtLB.MxAtlantic lower bathyal mixed sediment
8[00:08:52]00:00:56M.AtLB.CoAtlantic lower bathyal coarse sediment
9[00:09:49]00:05:34M.AtLB.Ro.MixCor.DisSolDiscrete Solenosmilia variabilis colonies on Atlantic lower bathyal rock and other hard substrata
10[00:15:23]00:10:55M.AtLB.MuAtlantic lower bathyal mud
2[00:19:08]00:10:02M.AtLB.Ro.MixCorMixed cold water coral community on Atlantic lower bathyal coarse sediment
11[00:26:19]00:04:57M.AtLB.Ro.MixCor.DisSolDiscrete Solenosmilia variabilis colonies on Atlantic lower bathyal rock and other hard substrata
3[00:29:11]00:26:17M.AtLB.Ro.MixCorMixed cold water coral community on Atlantic lower bathyal coarse sediment
12[00:31:17]00:29:08M.AtLB.MuAtlantic lower bathyal mud
4[00:55:29]00:40:56M.AtLB.Ro.MixCorMixed cold water coral community on Atlantic lower bathyal coarse sediment
13[01:00:26]00:04:57M.AtLB.Mx.SurOph.OphCerOphiomusa lymani and cerianthid anemone assemblage on Atlantic lower bathyal mixed sediment
14[01:05:24]00:04:50M.AtLB.Ro.MixCor.DisSolDiscrete Solenosmilia variabilis colonies on Atlantic lower bathyal rock and other hard substrata
15[01:10:15]00:01:24M.AtLB.CoAtlantic lower bathyal coarse sediment
16[01:11:40]00:02:13M.AtLB.Ro.MixCor.DisSolDiscrete Solenosmilia variabilis colonies on Atlantic lower bathyal rock and other hard substrata
17[01:13:54]00:01:05M.AtLB.Mx.SurOph.OphCerOphiomusa lymani and cerianthid anemone assemblage on Atlantic lower bathyal mixed sediment
18[01:15:00]00:02:09M.AtLB.Co.MixCorMixed cold water coral community on Atlantic lower bathyal coarse sediment
19[01:17:10]00:06:17M.AtLB.Ro.MixCor.DisSolDiscrete Solenosmilia variabilis colonies on Atlantic lower bathyal rock and other hard substrata
20[01:23:28]00:00:45M.AtLB.MuAtlantic lower bathyal mud
21[01:24:14]00:05:00M.AtLB.Mu.EreCor.AcaArbAcanella arbuscula assemblage on Atlantic lower bathyal mud
5[01:36:26]00:11:49M.AtLB.Ro.MixCorMixed cold water coral community on Atlantic lower bathyal coarse sediment

Porifera
Asconema sp. : 1038 : O
Asconema sp. (Porifera massive globose 14) : 650 : R
cf. Farreidae : 1142 : R
cf. Polymastia boletiformis : 1030 : R
Geodia cf. atlantica (Porifera massive lobose sp. 6) : 83 : F
cf. Geodia baretti (Porifera massive globose sp. 11) : 601 : O
Porifera encrusting sp. 1 (white) : 1 : R
Porifera encrusting sp. 10 (yellow) : 30 : R
Porifera globose lobose : 1178 : O
Porifera lamellate (bubbles) : 1156 : R
Porifera lamellate sp. 7 : 422 : R
Porifera massive globose sp. 13 : 648 : R
Porifera massive globose sp. 15 (Solenosmilia rubble) : 1051 : O
Porifera massive globose sp. 6 : 137 : O
Porifera massive globose sp. 9 : 380 : R
Porifera massive lobose sp. 32 : 1090 : R
Blue Porifera encrusting : 800 : R
Porifera vase (cf. Aphrocallistes) : 1162 : R
Cnidaria
Cerianthidae sp. 1 : 2 : R
Actiniaria sp. 20 : 605 : R
cf. Halcampoididae sp. : 984 : R
Actinernus michaelsarsi : 554 : O
Actinoscyphiidae sp. 1 (pink) : 1047 : R
Actinostolidae sp. 1 : 132 : O
Adamsia sp. : 1066 : R
Phelliactis sp. 1 : 255 : O
Stichopathes sp. : 560 : O
Leiopathes sp. : 305 : F
Bathypathes sp. (brown) : 284 : O
Parantipathes sp. : 1042 : F
Parantipathes sp. (branched) : 1161 : R
Stauropathes arctica : 547 : F
Telopathes sp. 2 (red) : 1181 : O
Corallimorphidae sp. 1 : 39 : R
Caryophyllidae/Fabellidae (indet.) : 1058 : R
Solenosmilia variabilis : 700 : F
Flabellum sp. : 1056 : R

Zoanthidae sp. 2 : 586 : R
Anthomastus grandiflorus : 278 : R
Radicipes cf. gracilis : 1044 : O
Chrysogorgidae sp. 1 : 1008 : R
Acanella arbuscula : 585 : O
Eknomisis sp. : 649 : O
Keratoisis sp. 2 : 578 : O
Lepidisis sp. : 557 : F
Isididae sp. (fine branching) : 1064 : R
Paragorgia (twiggy) (poss. Swiftia) : 1065 : R
Paramuricea sp. : 1050 : O
Paramuricea sp. : 1050 : O
Gorgonacea sp. (pink, Solenosmilia assoc.) (Jasonisis) : 1070 : O
Pennatula inflata : 1183 : O
Pennatula cf. inflata : 1083 : O
Distichoptilum gracile : 1108 : R
Umbellula sp. : 581 : O
Hydrozoa (flat branched) : 56 : R
Annelida
Aphroditidae sp. 1 : 146 : R
Serpulidae sp. 1 : 106 : O
Arthropoda
Chirostylidae sp. 2 (indet.) : 1054 : R
Paguridae sp. : 205 : R
Caridea (indet.) : 1077 : R
Munidopsis sp. : 1126 : R
Munnopsidae sp. : 1102 : R
Mollusca
Acesta excavata : 1062 : R
cf. Grimpoteuthis sp. : 1176 : R
Octopoda (indet.) : 659 : O
Echinodermata
Bathycrinidae sp. 1 : 1041 : F
Pentametrocrinus atlanticus : 436 : R
Anachalypsicrinus nefertiti : 1031 : R
Crinoidea sp. : 1072 : R
Crinoidea sp. 1 : 131 : R
Crinoidea sp. 1 : 131 : O
Asteronyx loveni : 471 : R

Ophiomusa lymani : 551 : R
Novodinia sp. : 1087 : O
Brisingidae sp. : 274 : F
Pseudarchaster sp. 1 : 433 : R
Porania sp. : 263 : R
Solaster endeca : 573 : R
Echinidae sp. (white) : 559 : R
Hygrosoma sp. : 1125 : O
Phormosoma placenta : 555 : R
Echinoidea sp. 5 : 572 : R
cf. Psolus sp. : 1049 : R
cf. Benthogone sp. (white) : 574 : O
Benthogone sp. : 432 : O
Chordata
Ascidiacea sp. (clear) : 591 : R
Ascidiacea sp. 2 : 20 : R
Squaliformes sp. : 569 : R
Hydrolagus cf. affinis : 1039 : O
Harriotta raleighana : 936 : R
Synaphobranchus kaupii : 440 : R
Ipnopidae sp. : 1078 : R
Hoplostethus atlantica : 651 : F
Coryphaenoides armatus : 1105 : R
Coryphaenoides guentheri : 577 : O
Coryphaenoides rupestris : 566 : R
Trachyrincus sp. : 446 : R
Lepidion cf. guentheri : 1160 : O
Guttigadus latifrons : 1166 : R
Phycis blennoides : 1020 : R
Halosauridae sp. : 1113 : O
Polyacanthonotus rissoanus : 552 : R
Cataetyx laticeps : 1111 : R
cf. Rouleina attrita : 1074 : O
Zoarcidae sp. 2 : 291 : R
Neocyttus helgae : 563 : R
Actinopterygii sp. 3 : 930 : R

Number of species = 107

© Marine Institute, MERC Consultants, Bernard Picton 2022