One of our team, Prof Lisa Crockett, is also the Senior Scientist on station, which means she liaises on all logistical matters with the company running Palmer on behalf of NSF. She is studying the effects of lipid oxidation on membrane function, specifically the role of mitochondrial cardiolipin, in these oxygen-rich waters. Antarctic fish lipids are more unsaturated (have more double bonds) than normal, which enables them to function better at low temperatures but makes them vulnerable to oxidation (e.g. omega 3 fatty acids are good in our diets, but their abundance is what makes fish go rancid quickly if not stored properly). The hypothesis to be tested on samples returned to Ohio is that the white-blooded fish are more vulnerable than red-blooded ones, as respiratory pigments may act as a buffer, but may have adjusted their phospholipid content to accommodate this. Lisa also conducts live webcasts on behalf of the NSF’s outreach programme (seen here with Ryan, our IT guy, showing some of the by-catch from a recent trawl).
I mentioned previously the impressive cardiac output of isolated icefish hearts, to follow that here’s a world first – an ECG trace from an icefish in one of the cradles I described earlier. Y axis in mV, X axis in seconds – a heart rate of about 10bpm, and currently dropping as the fish recovers from surgery!
The weather continues to be changeable, but that brings occasional breaks in the clouds for nice views, and this week saw rough seas bring a family of fur seals ashore outside the lab for a bit of respite on land. Handsome fellows, if a little bad tempered.
I’ve been asked about life here at Palmer. Many of the early Antarctic stations were either manned or established along military (usually navy) lines, and the military handle isolated small communities by applying the principle of a strict daily schedule.
So here it is: breakfast 06:30, lunch 12:00, dinner 17:30; in between there are coffee breaks with freshly baked snacks at 10:00 and 15:00. Now you might think that’s a lot of eating (it is!), but when working in the cold you need a lot of calories to keep warm (you also generate heat while digesting food – look up ‘specific dynamic action’), and for the support staff a routine breaks the day up into manageable chunks. For the scientists (aka ‘nerds’ for data-analysts and ‘beakers’ for lab-based researchers) there is time after dinner for more experiments before bed.
There are lots of chores to keep the place functioning; one person is assigned to help the cook each day, after dinner there is a team to clean up the kitchen and eating area (called GASH, a naval term for Gallery And Scullery Help) which we all have to do once a week, then there is weekly House Mouse – essentially a job jar from which everyone takes a ticket for a cleaning duty (toilets, labs, lounge etc). The week is broken up by other regular events: a station meeting on Saturday where everyone gets an update on what’s happening (or broken!), followed by a half-hour opportunity to shop at the store for toiletries, snacks (yes, there is still an appetite for more) and drinks. Then Sunday is a day off (for most people).
The other inhabitants of Anvers Island pay us a regular visit, which is a nice break from the same faces every day. The Sheathbills look lovely on their white plumage, but less attractive after they’ve been scavenging, and there are even seagulls! OK, strictly they are Southern Black-backed gulls, but still…
The temperature has dropped again and with it came welcome high pressure weather stability, with some nice sunrises and sunsets. A reminder that the base is on a maritime island comes daily in the form of visitors taking a break from wandering the oceans. This may be due to the need to find some land for moulting of feathers (the local GP population is finally ready to head out to sea again), for breeding (the sound of which carries for miles over quiet waters), or just hauling out of the sea to digest a heavy meal.
The latter case is certainly true for Leopard seals (a lean, mean, killing machine – one floated by with the remains of a penguin lunch being picked over by Sheathbills) and Crabeater seals (the most numerous pinniped in the world, but misnamed as they eat krill not crabs) who regularly haul out to watch the world go by.
The first results are in! I’ve teamed up with Professor Tony Farrell from the University of British Columbia (Vancouver) to study cardiac performance in the icefish that survive a) frigid waters and b) lack of respiratory pigments. Using an in situ preparation to measure the capacity of the heart to perform work we have shown an impressive cardiac output of 4ml/kg body mass at a heart rate of just 18 beats per minute (this can rise if the heart is slowed down). To put this into perspective, the human heart manages ‘just’ 1ml/kg at around 70bpm – and we have the advantage of being nearly 40oC warmer, with lots of respiratory pigments to aid shuttling of oxygen. I showed you a picture of the unusually large heart, now take a look at the uniquely white gills seen through their cavernous mouth. This is an amazing feat of physiological adaptation!
Tony has now left and I’ll be trying to match these data to measurements of heart rate in unrestrained fish, and comparing the performance of other species that do possess respiratory pigments. Check back for an update as those numbers come through!
In honour of this great event (what, you’ve never heard of it? check out http://www.bbc.com/earth/story/20150425-a-world-of-amazing-penguins) here’s a picture of a recent visitor to the station. In keeping with the Antarctic Treaty regulations, no visitor should go close enough to wildlife to cause any disturbance to their behaviour; I think we can safely say there was no problem in this case!