Highlights: 00:01:24 Sea pen field 00:33:33 Barnacles 00:52:06 Antipatharian

At the base of the canyon the sediment is sandy sediment with some pebbles and the occasional rock. The fauna here consists of xenophyophores, a variety of sea pens species and anemones, including cerianthids. Occasional ophiuroids and bamboo coral Acanella sp. and holothurians are present on the soft sediment. Rock or exposed bedrock where it occurs is colonised by encrusting sponges and stylasterid corals and on occasion brisingids. Fish species include eels and chimerids.

On the flanks of the canyon whip-like Stichopathes sp. are common; the ground is steep with hard ground in the form of stones, rocks and occasional exposed bedrock. Ophiuroids, glass sponges, Acanella sp. and bamboo coral are noted here with sea pens, holothurians and cerianthids occurring in the sediment. Continuing up slope barnacles are numerous on any available hard ground, the black corals Bathypathes sp. and Parantipathes sp. are also present.

Above 1700 m coral rubble and a small clump living Lophelia pertusa occurs. Barnacles, encrusting sponges and Stichopathes sp. are also noted. The substrate here is that of steep coarse sand with occasional rocks. Sea pens are abundant and also present are ophiuroids and the occasional xenophyophore. A variety of sea pens including Pennatula sp. and Umbellula sp. are common on soft sediment and the corals include Stichopathes sp. and Parantipathes sp., Leiopathes sp. and Lepidisis sp. On rock with a fine sediment overlay small clumps stone coral Madrepora oculata occur along with the black corals.

An area dominated by xenophyophores and sea pens cf. Pennatula predominate occurs on the side of the canyon in soft sediment. Ophiuroids and holothurians also occur and where there is hard substrate it is colonised by black corals barnacles and a variety of sponges including encrusting forms. Further up the canyon side hard substrate is colonised by a variety of sponges and corals, both stalked and motile crinoids and occasionally clumps of the stone coral L. pertusa and coral rubble. Fish species appear to be more prevalent here and include oreos, eel-like fish and grenadiers.

On a series of terraces and cliffs of varying height black corals, Leiopathes sp. and Stichopathes sp. are present along with both stalked and motile crinoids. On the ledges areas of living and dead L. pertusa occur; here a variety of sponges including glass sponges and large erect sponges are present along with anemones, including cf. Bolocera.

The overhangs are colonised by stalked and motile crinoids, Stylasteridae sp. and black corals. Grenadiers are also observed here.

Towards the top of the canyon flank the sediment is that of soft fine sand moving. The fauna here is dominated by cerianthid anemones and xenophyophores. Fish species particularly grenadiers appear to be more common here. On the occasional rock living and dead L. pertusa occur.

START VIDEO [00:00:00]/20:08 [1] The dive starts on mixed epifaunally rich mud/gravel dominated by cup corals and xenophyophores. [00:01:00] The ROV traverses right then moves forward again. [00:05:00] view obscured for 20s. The substrate becomes rippled with increasing gravel and pebbles. [00:11:00] [2] the xenophyophores now dominate, along with sea pens, especially Pennatula aculeata on gravel/pebble/mud with rare cobbles and boulders. [00:17:00] [3] the slope becomes steeper, boulders and cobbles are more common, the seapens are generally dominant, occupying the soft/mixed substrate, while barnacles occupy the hard substrate. Other encrusting fauna and some corals are also present. [00:22:00] A large dark jellyfish is encountered. [00:23:00] [4] A large flat circular boulder is encountered. The barnacles are now the dominant assemblage with many black corals Stichopathes sp. (OTU560) apparent upon closer inspection. P. aculeata continues on the softer substrate, although some Stichopathes are also seen here, attached either to pebbles or indicative of veneered bedrock. The cobbles/boulders and mixed substrate occur in patches of varying density. [00:50:00] stop to image Leiopathes, circling afterwards before continuing uphill at [00:58:00]. [01:00:00] [5] cobbles/boulders are relatively dense with some coral rubble and discrete living Solenosmilia variabilis colonies associated, along with other sparse mixed corals. The barnacles are still numerous, and pens continue on the mixed substrate. [01:08:00] [6] This area is dominated by Stichopathes sp., at first also accompanied by a massive globose/lobose sponge (possibly Geodia sp., OTU83). The mixed substrate patches are also dominated by Stichopathes with few sea pens, so this is likely thinly veneered bedrock. [01:17:00] Terraced cliffs of vertical/horizontal bedrock, mud veneer, and cobbles/boulders on terraces, continue with a similar assemblage. [01:21:00] ROV reaches the top terrace which supports a cobble/boulder field at first, with increasing pebble/mud veneer. [01:25:00] [7] cup corals and xenophyophores again dominate, now with frequent Acanella arbuscula. There are many fish species up here, with several sharks (Squaliformes) encountered and Coryphaenoides rupestris being particularly abundant. A couple of Radicipes sp. chrysogorgiid corals were also encountered. END VIDEO [01:58:00]/22:07.