So… what did you get up to today?
Well, I spent my morning on West Sands helping a friend search for seals. Dead or alive (personally, I was hoping for the latter).
I then got into the institute, imbibed around 2 litres of coffee (all the way from Cape Town, thank you SJI) and proceeded to perch on the windowsill of my third-story office to record a 2-minute synopsis of my PhD for Lars-the-guru. Because we needed the sounds of the ocean in the background, obviously. The best part about all of this is that nobody on our floor so much as batted an eyelash. The Masters students are in their final few weeks of write-ups so I’m surrounded my sleep-deprived younglings oscillating between despair and Jaffa-cake fuelled hyperactivity. I’ve never felt more sane.
PhD Comics is holding a competition at the moment, and the winner will get their thesis illustrated by THE Jorge Cham. But do you know how hard it is to describe your PhD topic in under 2 minutes? It’s taken me DAYS to get this right. I mean, there are seal submarines and an icy hostile ocean and little green cells and satellites and lasers involved… But then, I subscribe to the school of thought that if you can’t explain something simply, you don’t know the topic well enough to begin with. So I persevered, and this is the result:
The love of my life is the Southern Ocean… mainly because I’m a sucker for punishment. It’s icy and hostile, and whipped by some of the strongest winds imaginable. It also experiences the highest mean wave height of all oceans. Ships get tossed around like little rubber ducks, and equipment that works everywhere else gets crunched by ice.
It’s best to adore this ocean from a distance. As in, from deep space.
I can learn a surprising amount about the Southern Ocean by looking at satellite-derived ocean colour. Think of it as a treasure map pointing to secret spots of biological richness. Every marine food web is based on little green cells called phytoplankton, so wherever they are, you’ll find treasure-chests overflowing with LIFE. The thing is, according to satellites, there isn’t enough phytoplankton in the Southern Ocean to make it ‘rich’.
And yet… a range of amazing marine mammals, like southern elephant seals, choose this ocean as their feeding grounds.
Male elephant seals can reach 4 tons, and their relatively svelte counterparts weigh in at around 600kg. It’s these ‘skinny girls’ that interest me. Over the summer, they give birth and wean their pups without eating a morsel but their babies grow by 100 kg in 3 weeks. It’s not surprising then that the nursing mothers lose up to half their body weight over this period. What IS surprising is that they manage to pick it all up again in under 6 weeks while foraging in waters supposedly devoid of life.
That just doesn’t sound right! And it makes me wonder what the satellites are missing. Let’s not forget that we’re using sensors in deep space to measure something that’s microscopic… inaccuracies are not implausible, but then what else aren’t we seeing about this vital global ocean?
It’s a problem, but unique challenges tend to generate creative solutions. And this is why I get to tag post-breeding female southern elephant seals with lasers. Okay, I’m kidding, not lasers. Fluorometers which measure phytoplankton, and sensors for salinity, temperature and depth. Real-time in-the-water data.
Basically, I have an army of free-ranging, deep-diving blubbery submarines to help me test satellite accuracy AND determine if the phytoplankton is maybe even hiding at depths that the satellites can’t see to.
Because Science really is that awesome.