Entry 05
February 21 2025
Rainbows, sunsets, and on-deck incubators
Today began encouragingly with a rainbow over the back deck, and the first order of business: building deck incubators. A deck incubator is essentially a paddling pool for sample bottles – we cover them with blue light filters (like you might find in a theatre) and pipe through underway water from below the ship – thus maintaining ambient light and temperature conditions you might find a few metres below the water’s surface. With the help of Grant (Chief Petty Officer, Science), we constructed some state-of-the-art deck incubators that only overflowed a little (!).
We finished off the morning making up chemicals from stocks (solvents for chlorophyll measurements, acids and nutrients for our amendment experiments) and tidying up our filtering rigs, before it was time to settle down to some arts and crafts: aka, blacking out 24 carboys with rubble sacks. This is so when we bring back samples from the deep water we don’t shock them with the light levels and the surface, which is important when we’re measuring things like photophysiology.
The afternoon’s excitement was a float deployment. These floats are a part of the UK Argo project, measuring temperature, salinity and depth. Once we drop them in they adjust their buoyancy to sink down to around 2km, from where they are free to move with the ocean currents for about 10 days, gathering information about the movement of the water masses they pass through, before they resurface. On the way up they continually measure salinity and temperature to give density values, and as they surface they send back data by satellite to scientists ashore. We have a number of floats to deploy on this expedition, which will enable us to build a nice picture of what’s going on at a number of different locations.