As we head from the Porcupine Abyssal Plain to Southampton the seas turn from a crystal blue to ever increasing shades of green. The seas calm and our pace changes from going from station to station over to cleaning, organizing, packing and thinking of what we will do next time.
One of my main areas of interest is tracing the influence of climate through the upper ocean. This includes production of algae and plankton at the sun-lit surface and the sinking of some of this carbon-rich material (marine snow) through the water column and onto the seafloor. Because this sinking marine snow is a key food source for life on the seafloor, climate variation can have a close connection to abyssal marine life even though it’s separated from the atmosphere by three miles of cold dark water.
The PAP- Sustained Observatory systems have one of the most comprehensive sets of tools in the world to address this climate to seafloor connection. On this research cruise we have been able to take extensive sets of seafloor samples and photographs that will be used to make some of the most detailed estimates of the amount of life found on the abyssal seafloor. Accurate estimates of the sinking marine snow and the mass of seafloor life help track the stock and flow of carbon in the ocean. Estimates of how climate change might alter seafloor life in the Northeast Atlantic suggest that the mass of life at the PAP-SO could decrease by nearly 50% in a century (https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.13680). So making accurate estimates now is critical to understanding how this globally important change might occur.
The effort is only possible because of the efforts of the officers, crew, technical support and science teams working together and this trip had some unusual challenges. These included servicing one of the tallest moorings in the world as well as running one of the deepest trawl tows still done today. Thanks very much to them, only some of whom are pictured below.
So now it’s back to our labs, workshops and offices to look at what we have found and what the observatory will tell us as it reports data back to shore throughout the year (http://projects.noc.ac.uk/pap/data). And back to life ashore with family, friends and summer coming right along.
Written by Henry Ruhl.