CEES Extra seminar/AQUA seminar: Fatty acids in the marine environment, from photosynthesis to copepod lipids and sequestration
By Sigrun Jonasdottir
Marine ecosystems host the most abundant bioengineers synthesising fatty acids on earth, the phytoplankton that fix organic carbon from CO2 with the aid of sunlight which they subsequently channel towards the production of high quality lipids – the omega-3 (ω3) fatty acids. I follow the fatty acids from food to function in copepods where the dietary ω3 fatty acids play a fundamental role in reproduction, growth and survival. Copepods are the main vehicles for transporting the dietary ω3 fatty acids through marine food webs to fish and so on to humans. I follow the fatty acids further where they act as the main structural component of wax esters, a lipid type that copepods accumulate for long periods of food shortage. In autumn, trillions of copepods full of wax esters descend to great depths in the ocean basins for overwintering. In addition to being an energy source during this time of famine, the wax esters act as a highly specialized buoyancy control for the copepods. The consequence of overwintering is lipid catabolism at depth resulting in respiration and the waste product CO2. I conclude the journey from light to darkness with quantification of the carbon the copepods leave behind at the end of winter in the deep dark oceans – a “footprint” of major significance for the ocean’s biogeochemical cycles.
Senior research scientist
National Institute of Aquatic Resources
Section for Marine Ecology and Oceanography
Technical University of Denmark
Sigrun Jonasdottir takes part in the adjudication committee for Kristina Kvile's disputation the following day.