Day 26: Mud, Glorious Mud

Night shift processing cores
Cries of 'land' filled the chemistry lab yesterday, as the Hebridean islands came back into sight. Following a successful box coring campaign at the Hebrides Terrace Seamount, when scientists reverted to toddlers in the presence of mud, we were back at Mingulay for a final round of ROV dives and multibeam surveys.

Previously we have heard about the exciting things happening on the sediment surface. Equally exciting are the animals living inside the sediment layer. These beasts living inside the sediment are referred to as bioturbators. They build tunnels through the sediment and by doing so they allow oxygen and food particles to penetrate the deeper layers.

The SPI camera, which was introduced by Silvana, allows the visualisation of the water-sediment interface. This gives exciting snapshots of the sediment layer. Box corers are a great way to expand on that snapshot. They penetrate the sediment (on this cruise with the surface area of 2.5 square m) and collect a block of sediment. The penetration depth depends on the speed it is lowered at and the sediment consistency.
Day shift

The samples that are collected are then sliced up into different layers of sediment and sieved, which generally turns into a team bonding exercise because all hand are needed on deck (Pic 2 & 3). Samples vary greatly with distance to seamounts and corals and occasionally we also find animals such as xenophyophores on the sediment surface. For those that are unaware, xenophyophore are giant singular celled protists that can grow to up to 10 cm in diameter. With all this muddy work, the ship deck tends to need cleaning afterwards...
Cleaning the deck