Highlights: 00:28:32 Antipatharian coral 00:32:55 Solenosmilia, sea fans & antipatharian corals 00:38:10 Orange roughy 00:44:11 Hexactinellid sponge - Aphrocallistes 00:45:57 Solenosmilia, sea fans & antipatharian corals 00:52:17 Hexactinellid sponge - Aphrocallistes

Mainly biogenic sediment. Sponges are frequent at this site including glass sponges, mainly Aphrocallistes and Pheronema. Moving up slope Leiopathes, Paragorgia and Eknomisis are evident as are orange roughy. Pebble and soft sediment substrate at the top of slope with more glass sponges, stylasterids and orange roughy.

START VIDEO [00:00:00]/23:23 The video starts on barnacle gravel substrate. [00:16:00] ROV samples 2 pushcores. [00:16:00] ROV leaves the bottom, only blue water for 1 minute. [00:17:00] [1] Continues on barnacle gravel sediment moderately flat/gentle up slope dwelled by several species of sponges. [00:19:00] Shark egg cases (no ID), possibly of Galeus melastomus OTU1005 (encountered by the end of the transect (1 juvenile)) or Rajiformes sp.1 OTU652. [00:28:00] [2] Here no more barnacle gravel. Now boulders/cobbles/mud/sparse coral gravel take place on steep up slope with many associated epifauna, including Leiopathes sp. and glass sponges. Large boulders host isolated Solenosmilia variabilis aggregations. [00:33:00] ROV stops for imagery of pink octocorallia (possibly Paragorgia sp). [00:38:00] the ROV moves slowly on the right and then forward. [00:43:00] [3] Mosaic of coral framework (mostly dead) and boulders with abundant Aphrocallistes sp. OTU264, Porifera lamellate sp.7 and Porifera encrusting sp.2 . [00:45:00] ROV climbs a steep bedrock with overhanging Solenosmilia variabilis colonies (living/dead), encrusted sponges and soft corals. [00:48:00] [4] Now the ROV reaches the summit. The site is dominated by Asconema sp. OTU1038 and Aphrocallistes sp. on coral gravel/rubble/sparse large cobbles flat/gentle up slope. Abundant Caryophyllia sp. OTU6 on gravel. [00:50:00] ROV stops for imagery of Aphrocallistes sp. (for less than a minute). [01:00:00] Now the substrate changes into large boulders/bedrock covered in coral gravel. Same epifauna as in the last biotope type. Here Orange Roughy are frequently encountered. [01:06:00] [5] Here gravel and sand/mud sediment on a gentle down slope with sparse boulders where encrusted sponges co-dominate with Aphrocallistes sp. and Porifera lamellate sp.7. [01:11:00] [6] now coral rubble and coral gravel intersperse with boulders/bedrock. Same dominant epifauna. A few Syringammina fragilissima observed sparsely on gravel/sand/mud sediment. [01:16:00] [7] Now boulders/bedrock is the primary substrate hosting abundant sponge aggregations and hydrozoa species. [01:20:00] [8] Again substrate changes into mud/gravel/sparse boulders on gentle down slope with sparse sponge aggregations. [01:35:50]-[01:41:00] ROV stops for imagery and sampling 1 pushcore. [01:41:00] [9] Now gently upslope on mud/gravel sediment with sparse cobbles/boulders hosting sponges. [01:41:00] ROV stops for imagery of Aphrocallistes sp. and encrusted sponges on boulders until END VIDEO [01:46:00].

N. B. This site is of particular interest for the abundance of small sponges, mainly Aphrocallistes sp. and (possibly) Porifera lamellate sp.9 (foliate). Moreover, throughout the transect, 26 individuals of Hoplostethus atlanticus (Orange Roughy) – which is assigned to the IUCN Vulnerable species- are encountered. Additionally, Primnoa resedaeformis OTU54 is rarely encountered in the North East Atlantic. There are records from Canada and Norway but rarely from the NE Atlantic at -1100 m depth (however species is recorded in Davies et al 2017).