Entry 12
March 01 2025
3am starts, squids, an unfortunate event, snow catchers, and red-light head torches
The first of March brings with it an Aquarius moon (according to my moon journal), the beginning of meteorological spring, and, for these eager scientists - our first pre-dawn CTD!! Standing in the main lab at 02:59, we watched the profile as it descended to about 300m (a veritable 'dip' compared to its 6km capability) and returned with its bounty - 24 20L Niskin bottles filled with water from various depths through the profile. Not only this, but we were treated to a display of a shoal of squid hunting a marlin in the spotlight just off the aft deck - which stopped play on the CTD sampling for a minute but was totally worth it.
Once it was back on deck I set about filtering for my genetics and fixing samples for flow cam (and had a slight mishap with some Lugols which, for the uninitiated, is essentially straight iodine!). And, just like that, I had my first complete set of genetics samples from a real pre-dawn CTD. I decided to abandon my vacuum filtering rig and run all my samples through Sterivex filters off a peristaltic pump which worked an absolute charm - my deepest thanks go to Prof Mark Moore for his generous donation of the filters, which were a luxury cost that I would have struggled to justify on a PhD budget.
Around lunchtime we were able to catch view of a couple of marine snow catcher deployments - a fan favourite of mine. These snowcatchers enable us to see what the particles in the water are made of, their carbon content, size and sinking speed. This goes back to our theory of the biological matter in the surface ocean sinking to the seafloor, locking carbon out of the atmosphere. The hypothesis here is that we should see more large particles over the mid-Atlantic ridge due to internal waves pushing more nutrients, which leads to bigger particles, which sink faster, locking away more carbon. You know the drill by now.
In the afternoon we had to start filtering another set of incubation experiments from the previous day. These required filtering in the dark which meant it was time to don the red headtorches
