So, after being safely back on land and suitably warmed, what happens now? First off, have some numbers:
18 stations sampled
152 water samples fixed to allow plankton cell counts
402 water samples filtered to collect particulate matter
485 copepods frozen
12590 eggs counted (each one was actually counted three times, and most were frozen)
No wonder I was seeing copepod eggs whenever I closed my eyes!
And now, after rooting through photos taken by others on the cruise, I can offer you a close-up of a beautiful calanoid copepod, the stars of the show. This was taken with a particularly expensive Leica microscope with digital camera, with the copepod on a fine mesh beneath. The red pigmentation varies between individuals, and between the similar species in the Calanus group. To work out their life stage – and most importantly, whether they are old enough to spawn – you have to count the segments in the the tail bit, called the urosome. It’s hard to tell from this picture as the mesh is in the way, but this looks like an immature one.
My samples remained on the ship, and don’t get back until 9th August, when the RRS James Clark Ross will dock in Southampton. This is when the real work begins! I can’t wait to get started, and I have already started planning for the next cruise in 2019.