Author & Pictures: Philipp Süßle

It´s dark, cold and moist. Peculiar sounds are coming from one corner of the room. The plankton wheel is spinning relentlessly. In the other corner, a glooming monitor is showing a continuous rain of particles, diving the lab into a cold light. Wanja and I are wearing thick onesies to keep warm. I guess this is what it takes to measure sinking velocities and remineralization rates of marine snow at in-situ conditions. At least, we don´t actually have to hop into the freezing cold fjord to do so.

After a rather “slow” start to the experiment, the first data is coming in and the last tweaks to the methods are done here and there.

The two parameters we are testing are crucial to estimate the depth attenuation of the biological carbon pump. How much of the biomass produced in surface layers will sink to the deep ocean?  How will ocean alkalinity enhancement change this depth attenuation? Will calcifying organisms speed up sinking velocities or reduce remineralization rates? This will largely determine the CO₂-sequestering capability of the biological carbon pump. To responsibly implement ocean alkalinity enhancement as an active carbon dioxide removal technology, we need to understand it´s influences on the biological carbon pump. Let´s find out!