Saturday, December 3, 2011

Middle of what?

It’s time to pause for breath and give a brief overview of the work that is being done on board.

We have been exploring ‘Middle of What’ seamount for three days now. This is a smaller than ‘Coral’, but larger than Melville bank, which we visited last month. Strong currents at depth have made exploration more difficult using our underwater vehicles (ROV Kiel6000 and Hybis).
‘Middle of What’ seamount is crossed by a fault line and reveals quite steep slopes, cliffs and cone features that are possibly underwater volcanoes. Its summit is at 1,000m depth. Unfortunately, most of the more accessible area on the main seamount has been flattened by trawls and is mostly devoid of complex framework. But, in some areas, we have seen amazing coral reefs and coral gardens (some bamboo corals were up to 3m height!), orange lobsters and different fish species including many small energetic sharks.

We have completed several explorations of the site and Clare was, as usual, scrutinizing the screen whilst the robot is lowered through the water column looking for jellyfish (see blog post of 14 Nov). These dives allow us to explore the deep-sea habitats by watching the live images on the main lab screens. We are doing several transects to cover the largest area possible and sample the seabed fauna.

Everyone is concentrated on the samples: Michelle is examining corals (see blog post 22 Nov); Tim, Peter and their colleagues are sorting the sediments that have been cored (25 Nov); David is identifying the pycnogonids (sea spiders) that we find on a coral (2 Dec); and so on …
Each animal and each sample is preserved in alcohol or formalin to allow taxonomic analysis later on.

The whole night of bathymetric survey (see blog post of 16 Nov) was well worth it as new maps of the relief of the seabed have been compiled.

One of the cone feature (height 200m)
which supports an abundant and diverse fauna.