by Winnie Courtene-Jones
Today two OSNAP moorings were collected, these were deployed on the east and west flanks of the central region of the Rockall Trough during a cruise in July 2016. The moorings have a number of instruments and floats fastened to a long chain which collect temperature, salinity and water velocity data throughout the water column. Upon sending an acoustic signal from the ship, these moorings are released from the seabed and the floats come up to the surface, where they can be brought on board.
This makes the process sound extremely simple but in reality locating and hauling the mooring on-board is a bit more tricky. The ship was a hive of activity and watching the skill of the crew was very impressive; they manoeuvred and lowered the heavy chains and floats, and delicate instruments onto the deck with ease.
Given that this equipment has been in the water for the last 10 months a number of marine organisms had colonised the floats. Those floats nearer the surface were colonised by large barnacles, while those at a depth of nearly 500m had large anemones and some cold water coral on its surface. It’s fascinating to see these establishing themselves in the deep sea after a relatively short period of time. Individuals were sampled to investigate the abundance of small pieces of plastic (microplastics) ingested by species inhabiting the mid-waters in the North East Atlantic Ocean.
Photos by Winnie Courtene-Jones