by Antonia Doncila, Edinburgh University
Life at sea never ceases to amaze, especially when you are on a research expedition. I am very proud to call the RRS Discovery my home for this month, as we cruise in the subpolar North Atlantic. The Extended Ellett Line transect covers a primary export route of Arctic waters into the North Atlantic and because of that I have joined the team to analyse and quantify the Arctic nutrient exports. In our changing world, the Arctic is warming twice faster than any other region on the planet. This warming translates into melting sea-ice, increasing the freshwater content of the basin and altering the biogeochemical cycles of this ocean. Because the Arctic Ocean modulates the global oceanic nutrient and salt balance, any environmental changes happening here can lead to altered water and nutrient exports into the North Atlantic. These exports exert control on the North Atlantic vertical nutrient profiles, upper ocean mixing regimes and ultimately local primary productivity. That is why I am interested in the nutrient exports from the Arctic into the North Atlantic: to understand how the two oceans are linked and how they will interact in the context of climate change.
But it is not just my work that is exciting. Some of my colleagues deploy devices named moorings across the entire water column in key areas. These will take continuous measurements of water, temperature, salinity and current velocity at regular depth intervals throughout the entire year. After a year, the moorings are recovered and the data collected shows how different water masses travel and interact and how they change their properties on a seasonal basis. Repeating this every year enables scientists to create a timeline which will highlight how the north Atlantic changes over time. The amazing work done on-board doesn’t end here. Some colleagues analyse the oxygenation of the vertical water profile, others look at microplastics abundance in the deep sea while others take sediment cores which are valuable paleoceanographic records. Every day something different happens and even as a scientist, there is so much I have learned during this cruise, simply by interacting with and observing my colleagues doing their work.
Apart from the rich work experiences, this cruise also offers me rich life experiences. Just from gazing at the vast open water and the powerful waves which are rocking our sturdy ship, makes me truly grasp the majestic greatness and strength of the ocean. It is stunning how these cold, restless waters are home to some of the most gracious creatures on earth: the cetaceans. We are now getting to the middle of the expedition and yet I have seen enough whales and dolphins to last me a life-time. It is just mesmerising how they swim so peacefully in the rocky waters, which would be fatal even to the strongest men, in a matter of minutes. Every time we deploy analytical devices in the water, pilot whales or common dolphins come in great numbers close to the ship, surrounding it, curious as to what we are doing. It feels sometimes that they are as much observing us as we are observing them, which can only make one feel honoured.
I wish we had an Ernest Hemingway or a Herman Melville on-board to take onto the impossible task of describing our adventures at sea. Words are simply not enough for me. However, I can certainly say one thing, until we are docking in Reykjavik, in two weeks’ time, it is just us and the open water…and an ocean of questions and lessons to be learned that will refine us both as scientists and as mere human beings.
Photos by Antonia Doncila