12 June Day 3

Anna Macey

The last time I was aboard RRS Discovery we spent our time between 12^o and 28^o North so this cruise (between 64^o and 56^o) is a slight change for me.  Although we have been lucky with the weather so far, with sunshine and light winds, however things are slowly picking up and the boat is moving a little bit more.  On this cruise I am interested in the effect of Iron availability on phytoplankton physiology (phytoplankton are the microscopic photosynthetic organisms in the sea, which larger organisms feed on). Iron is a fundamental requirement for many cellular processes in the ocean and I will use the samples I collect to look at the effect of Iron availability on proteins involved in photosynthesis. Iron availability has the potential to limit the abundance of these proteins and set a limit on metabolic activity and hence primary production in the ocean (Iron data collected by Sebastian and Chris from the NOC – see later blogs to find out what they are getting up to on the cruise). One of my main activities on the cruise is to filter water to enable me to extract proteins from the filters. I collect this water from both the CTD (see Marie’s blog for CTD explanation!) when we are on station and from an underway sampling system, which pumps water from the surface of the ocean into the lab, when we are steaming.   

A tradition on research cruises, when CTDs are going down into deep water, is to get out our permanent markers and practise our drawing skills. Why, I hear you ask, well as you descend into the depths of the ocean pressure increases. A way to test this is to send polystyrene cups down attached to the CTD to the bottom of the sea. The air in the polystyrene gets compressed so the cups shrink to a small size. People generally adorn their cups with drawings (generally bad attempts of the ship in my case) and words to serve as a memento from the cruise.

We are only on day 3 of the cruise but I have already settled into life on board, enjoying meal times (the food is brilliant!) and catching hours of sleep when I can.