Picturing the Deep Contd.
All images: NOCS
In addition to the cameras, Autosub6000 has a suite of instruments that collect fine-scale bathymetric data that gives the shape of the seafloor; mapping acoustics that will reveal the composition of the seafloor – mud, rock, sand; and environmental sensors that measure temperature and the amount of particles in the water. While Autosub6000 gathered data, the scientists took mud core samples to find out what is living in the seafloor. The cores confirm variation in sediment type as well as collecting microscopic worms, crustaceans, and bacteria. In an area of cliffs too steep for Autosub6000, the scientists used SHRIMP (Sea floor High Resolution Imaging Platform) a towed camera system developed by the National Oceanography Centre. The SHRIMP system had forward and downward video cameras and a downward facing still camera. SHRIMP has revealed rare rocky outcrops in the abyssal plain in an environment that is largely flat and covered in muddy sediment. One of the key aims of this research is to find out the effect that climate change has on the deep ocean floor. Dr Ruhl continues: “With no sunlight penetrating these abyssal waters, the animals live on material that falls from the upper ocean, phytoplankton, zooplankton and faecal matter – plankton poo.
We believe that the settling of this sinking food supply differs in different parts of the abyssal plain including the hills and flat areas. Our research will help disentangle how projected changes in this sinking carbon food supply will differ on abyssal hills versus flat areas in the largest habitat on Earth While we used this robotic technology to look at deep sea ecology, we expect the use of such large-scale survey methods to expand including for use in surveys for understanding possible oil and gas industry impacts, as well as seafloor mineral mining.” The Porcupine Abyssal Plain is the site of a long-time series research station (http://noc.ac.uk/ocean-watch/openocean/porcupine-abyssal-plain), where research has been taking place since 1989 to measure the global carbon budget. This research was funded by the Natural Environment Research Council.
UT2 August 2012
The August edition of UT3, the magazine of the SUT