2014-02-12T16:51:00

Ocean

2014-02-12T17:24:00

A yoyo transect was run for 0.5 nm at Station 10 over a depth range of 587 to 602 m, coinciding with the location of a short term oceanographic mooring M1. The video revealed abundant marine snow throughout the water column, with the seafloor covered in diatom drifts. The high diatom flux and deposition reflects the bloom conditions at the time of sampling. The still images revealed a mixed benthic community, consisting of abundant infauna, mobile feeders (such as brittle stars and urchins) and some sessile suspension feeders (gorgonians, bryozoa, sponges and anemones). Brittle stars and burrows were the most dominant taxa throughout. Sessile taxa were often associated with drop stones, which were either fully visible or partially buried in the sediment.

2014-02-17T16:26:00

Ocean

2014-02-17T17:04:00

This transect was within the deep basin region on the western part of the survey area, at depth of 895 m. The chirp line indicates the presence of a ‘toothpaste’ reflector, 3-4 m thick. The benthic fauna along this transect were characterised by sparse mobile forms and infauna, with highest abundances of brittle stars, urchins and polychaetes. Burrows were present throughout, with crustaceans occasionally observed at their head. Diversity and biomass were relatively low throughout. Sessile epifauna, such as bryozoans, sponges and anemones, were occasionally observed, mostly associated with dropstones. The video recorded thick marine snow through the water column, and diatom drifts were visible on the seafloor.

2014-02-21T05:26:00

Ocean

Yoyo failed

2014-02-21T05:50:00

Ocean

Yoyo failed

2014-02-22T04:34:00

Ocean

Yoyo failed

2014-02-23T13:44:00

Ocean

Yoyo failed

2014-02-24T12:53:00

Ocean

2014-02-24T13:13:00

This transect was run across the top of a shallow moraine (275 m water depth) on the eastern part of the survey area. The chirp line indicates a hummocky surface, with an elevation range of 2-3 m, possibly reflecting iceberg scouring. Sediments are not visible in the sub-bottom reflectors. The benthic fauna observed were characterised by a range of epifauna, dominated by bryozoans, with a variety of massive, hollow and encrusting sponges, bottlebrush gorgonians, whips and ascidians also abundant. Crinoids were also abundant, often perching on top of the sponges and gorgonians. Gravel, cobbles and boulders provide hard attachment points for the epifauna.

2014-02-24T14:59:00

Ocean

2014-02-24T15:45:00

This transect crossed obliquely over a dune complex, with amplitudes of up to 4 m, at a depth of 460 m. The presence of ice rafted debris (IRD) of gravel up to boulder sized clasts has enabled the development of a diverse epifauna community on areas of hard substratum. The epifauna is comprised of bryozoans, encrusting sponges, bottlebrush gorgonians, ascidians and anemones. Muddy sands away from areas of IRD are populated by a much sparser mobile and infaunal community. Brittle stars are dominant, with burrowing and pencil urchins, polychaetes, crustaceans and sea spiders also occurring.

2014-02-24T16:52:00

Ocean

2014-02-24T17:25:00

This transect traversed a major moraine feature in the north eastern part of the survey area, imaging from the base to the top of the feature. Along the base of the moraine, sediments were predominantly muddy/sandy with a dominance by anemones and brittle stars, and burrowing and pencil urchins and large clam burrows were also observed. On the moraine itself, gravels, cobbles and boulders were more dominant features of the substrate, resulting in the occurrence of a diverse epifaunal community. While brittle stars remained a dominant component of this community, bryozoans, encrusting sponges and bottlebrush gorgonians were also abundant.

2014-02-25T05:29:00

Ocean

Yoyo failed on first attempt

2014-02-25T06:09:00

Ocean

2014-02-25T06:36:00

This transect was designed to image a crag and tail feature at 680 – 700 m, just west of the interface between the crystalline basement and sedimentary deposits. The presence of large tabular icebergs meant that the transect could not be run in the preferred south easterly direction, and had to cut short before reaching the upslope extent of the feature. The seafloor is characterised by muddy sediments, which can be seen as a fine toothpaste reflector in the chirp profile along the first part of the transect. The fauna were predominantly mobile and infaunal forms, with brittle stars, crustacea, holothurians, polychaetes and urchins occurring throughout, however, gorgonian whips were also abundant along parts of the transect.

2014-02-25T07:57:00

Ocean

Yoyo failed

2014-02-26T21:43:00

Ocean

Yoyo failed

2014-03-03T13:33:00

Ocean

Yoyo failed on first attempt

2014-03-03T13:58:00

Ocean

2014-03-03T14:24:00

This transect was run across a shallow section of crystalline basement (340 m water depth) in the south western part of the survey region. The aim of the transect was to understand the fauna associated with this shallow outcrop, and to provide a broader context for understanding the sedimentary processes across this plateau and adjacent deep channel (Yoyo49). The substrate consists of basement outcrops, with boulders, cobbles and gravel also present. Sandy sediments were observed in the first part of the transect and between areas of harder substrate. The taxa had a relatively high diversity and biomass, with the primary taxa comprised of bryozoa and brittle stars, with a variety of massive and hollow sponges also abundant at times.

2014-03-03T16:25:00

Ocean

2014-03-03T16:49:00

This transect was located within a channel that has incised 150 m into the crystalline basement. The water depth in the deepest part of the channel is 538 m. The flanks of the channel are comprised of basement outcrop, with cobbles and gravelly sediments also common. The deepest parts of the channel, along the eastern side, have a more muddy composition, with thick drifts of diatoms. Brachiopods, brittle stars and bryozoa were abundant, particularly on areas of basement outcrop. A diversity of massive, hollow and encrusting sponges, ascidians, gorgonians, anemones, crinoids and polychaetes were also present on the rocky substrate. Sea spiders, along with brittle stars, were most abundant on the muddy sediments, with urchins present throughout.

2014-03-03T19:53:00

Ocean

2014-03-03T20:25:00

This transect was selected to cross directly over the crests of several parabolic dune features. Sand could be seen clearly in some of the images, particularly within large clam burrows. Elsewhere, the sediments are overprinted by recent diatom deposition and the occurrence of IRD. The IRD was present as boulders, cobbles and gravel, with the blackened surface of the boulders indicative of manganese oxides. The boulders were densely colonised by epifauna, comprised of bryozoans, gorgonians, massive and encrusting sponges and anemones. Crinoids were also commonly observed perching on the epifauna. Some of the boulders were partially buried within the sediments, indicating emplacement prior to the deposition of the upper sediments.

2014-03-03T23:19:00

Ocean

2014-03-03T23:50:00

This transect crossed the flanks of a basin containing thick (~12 m) sedimentary deposits in the north eastern part of the survey region. The sediments imaged by the camera were muddy, with diatom drifts visible on the surface. The fauna were dominated by anemones, brittle stars and gorgonian whips. The abundance of sessile epifauna on this transect suggests that food particles were advected across this area in suspension. Mobile feeders, such as the brittle stars, burrowing urchins and holothurians were also observed.