All about clocks

It’s very rare indeed that you can immerse yourself in science, 24 hours a day, for days on end. But that’s exactly what’s going on aboard the HH (R/V Helmer Hanssen). We sleep (a little), eat (really great food) and work, (“crunch” data) and discuss science (when not sleeping, eating or crunching data). It’s terrific, and a privilege to be part of this cruise!

I’m interested in zooplankton behaviour and how they respond to light, or more specifically lack of it. You see, most of the planet experiences very regular light/days cycles with virtually all biological processes “entrained” to this cycle. Underpinning this is the circadian clock, a molecular machine which allows animals and plants to anticipate future cyclic events, much like you or I when we wake in the morning just before the alarm clock goes off – it’s our circadian clock, not the alarm telling us when to rise! In order to study this process we need a special device that measures cyclic behaviour, no mean feat when you are looking at a zooplankton only a few millimetres long. We use arrays of “activity monitors”, more usually found in labs working on fruit flies, which enable us to house hundreds of animals all individually swimming about in test tubes about the length of your index finger. If we see a rhythm of activity we know that this is the expression of the circadian clock and may aid survival when light is limiting. However, the activity monitors also provide data on frequency of swimming, telling us if they are hibernating or still actively looking for food. We can also tell differences between male and female swimming, useful for example, in understanding mating behaviour. Ultimately, since zooplankton are at the base of the food chain, supporting fish stocks and sea mammals, deciphering how they function and survive during the Polar Night is central to what we aim to achieve. However such science requires a lot of teamwork and without the researchers aboard the HH to help, and for inspirational discussions leading to new experiments, none of this would be possible.

Now it’s time to sign off and check on the animals, download the latest activity data. It’s a bit like being a detective I imagine, the data will hold clues and lead to the next experiment. I suspect it might be a long night.

-Kim Last (Professor, SAMS)

Kim’s activity hotel–it was a busy place during the cruise, at capacity almost every single night!
Kim working on the vials that will store individual animals (like copepods).
The “rooms” of the activity hotel.
To recreate a natural environment, no white light was used during the experiments.