D536 Transect RB12 Gravel/cobble/boulder/carbonate cliff with Lophelia/Madrepora reefs. Priority. Features: Escarpment, Ridge. Water depth: -550 m. TL: 2.6 km SOL: 14° 46.124' W 56° 0.521' N
Highlights: Sponges on boulders & chimaera Chimaera Demosponge Fishing gear
Relatively flat seafloor comprised of soft sediment, with low faunal diversity; the most conspicuous fauna being the echinoid Cidaris cidaris. This ground transitioned to coarse sediment comprised of pebble/cobbles with desmosponges, anemones, Cidaris cidaris and holothurians. Abandoned fishing gear caught on boulders and ledges is observed. A vertical ledge with the stony corals, Madrepora and Lophelia, desmosponges, anemones and cushion stars are also observed. Numerous large hydrozoans (Stylaster sp.) are observed on bedrock formations. Terraces occur with Cidaris,desmosponges, and some encrusting sponges. Sea bed levelled out again and faunal diversity decreased sharply.
START VIDEO [00:00:00]/23:39 [1] Gravel and sandy gently upsloping bottom with sparse pebbles with dominant Cidaris cidaris. [00:01:00]-[00:10:00] two pushcores. [00:24:00] Mud and cobbles sediment with dominant C. cidaris. [00:37:00] [2] Mosaic substrata (gravel, sand, boulders) hosting Lophelia pertusa/Madrepora oculata reefs with sponge aggregations (poss Mycale lingua OTU171) co-dominant with C. cidaris. Frequent sights of Coryphaenoides and Lepidion species. [00:43:00] [3] Now sandy sediment again with sparse cobbles on steep continental slope. C. cidaris as dominant species with frequent encounters of Parastichopus tremulus OTU266. [00:49:00] [4] Carbonate crust on steep continental slope covered in boulders hosting L. pertusa/M. oculata reefs. [00:56:00] [5] Now substrata changes again into sand sediment on steep continental slope with dominant C. cidaris. [01:00:00] [6] Again carbonate crust on steep slope with abundant C. cidaris. [01:04:00] ROV climbs up the carbonate crust and explores the moderate slope edge on top of the crust that host L. pertusa/M. oculata reefs with M. lingua and Stylaster sp1 OTU361 aggregations. Now sand with boulders hosting L. pertusa/M. oculata reefs and porifera lobose or globose (poss M. lingua). [01:19:00] [7] vertical bedrock and soon changes into large bedrock on a moderate uphill slope with dominant Actiniaria sp.13 OTU478 and frequent encounters of M. lingua. [01:30:00] [8] Sandy flat/moderately downhill bedrock with cobbles. M. lingua and sea anemones as co-dominant species. [01:39:00] The ROV sits at the bottom until END VIDEO [02:00:00]/01:40.
N. B. Synaphobranchus kaupii throughout the whole transect. [01:09:00] Centrophorus squamosus OTU1048.
Progression | Start | Duration | Code | Name |
---|---|---|---|---|
1 | [00:00:00] | 00:45:31 | M.AtUB.Co.UrcCom.CidUrc | Cidarid urchin assemblage on Atlantic upper bathyal coarse sediment |
2 | [00:45:32] | 00:18:50 | M.AtUB.Co.UrcCom.CidUrc | Cidarid urchin assemblage on Atlantic upper bathyal coarse sediment |
4 | [01:11:29] | 00:06:31 | M.AtUB.Co.UrcCom.CidUrc | Cidarid urchin assemblage on Atlantic upper bathyal coarse sediment |
5 | [01:18:01] | 00:00:01 | M.AtUB.Ro.MixCor | Mixed cold water coral community on Atlantic upper bathyal rock and other hard substrata |
4 | [01:18:03] | 00:07:42 | M.AtUB.Ro.MixCor | Mixed cold water coral community on Atlantic upper bathyal rock and other hard substrata |
5 | [01:25:46] | 00:04:53 | M.AtUB.Co.UrcCom.CidUrc | Cidarid urchin assemblage on Atlantic upper bathyal coarse sediment |
6 | [01:30:40] | 00:19:53 | M.AtUB.Ro.MixCor | Mixed cold water coral community on Atlantic upper bathyal rock and other hard substrata |
7 | [01:50:34] | 00:22:29 | M.AtUB.Co | Atlantic upper bathyal coarse sediment |
Porifera
Mycale lingua : 171 : R
Porifera encrusting globose (pale) : 75 : R
Blue Porifera encrusting : 800 : R
Cnidaria
Actiniaria sp. 10 : 344 : R
Actiniaria sp. 13 (pink/purple) : 478 : R
Actiniaria sp. 24 : 907 : R
Bolocera tuediae : 12 : R
Parantipathes sp. : 1042 : R
Desmophyllum cf. dianthus : 335 : R
Lophelia pertusa : 250 : R
Pliobothrus sp. : 207 : R
Stylaster sp. 1 : 361 : R
Annelida
Serpulidae sp. 1 : 106 : R
Arthropoda
Paromola cuvieri : 304 : R
Caridea (indet.) : 1077 : R
Decapoda sp. 3 : 543 : R
Echinodermata
Brisingidae sp. : 274 : R
Ceramaster/Peltaster/Plinthaster sp. 1 : 234 : R
Ceramaster/Peltaster/Plinthaster sp. 2 : 388 : R
Asteroidea cf. sp. inulosida : 1186 : R
cf. Echinus (deep pink spine) : 1129 : R
Cidaris cidaris : 211 : F
Araeosoma fenestratum : 188 : R
Parastichopus tremulus : 266 : O
Chordata
Galeus melastomus : 1005 : R
Centrophorus squamosus : 1048 : R
Chimaera monstrosa : 265 : R
Synaphobranchus kaupii : 440 : R
Merlangius melangus : 1019 : R
Molva dypterygia : 245 : R
Coryphaenoides armatus : 1105 : R
Lepidion cf. guentheri : 1160 : R
Lepidion eques : 249 : R
Phycis blennoides : 1020 : R
Lophius piscatorius : 273 : R
Epigonus telescopus : 1018 : R
Helicolenus dactylopterus : 227 : R
Number of species = 37
© Marine Institute, MERC Consultants, Bernard Picton 2022