First science lecture

The Antarctic naked dragonfish surrounded by it's eggs
Current conditions: Con3.  Temp -6ºF (-29ºF with wind chill). Mostly cloudy.  Population: 318


You may have noticed that, despite my predictions, the number of people on the ice is not rising much.  Over the last four days, the visibility has been too limited and the winds too harsh for planes to land.  So we are still a small, intimate population.

Due to weather, American Night was canceled again last night but at least we got our first science lecture on Wednesday.  Below is what I learned (and hopefully did not learn wrong!)


1.  Anne is Canadian (note hat) and got her PhD at UBC!  2.  Rockfish in the Crary Aquarium. 
3.  Set up for temperature-acidity experiments
Anne Todgham, Assoc. Prof. of Animal Science at UC Davis, talked about her passion for Antarctic fish.  An environmental physiologist, Anne began by talking about polar ocean ecology.  A "polar convergence zone", or polar front, circles the continent.  This convergence zone, where the cold water of Antarctica sinks under the warmer sub-Antarctic water,  creates an ecological barrier to species migration and intermixing.  The polar front is a huge, oceanic equivalent of a tree line on a mountain.  Consequently, Antarctic species are seen nowhere else, and the species in warmer climes are not seen here. Even species that appear similar on the two sides of the convergence zone are genetically quite distinct.    

Because the water has been cold here for 14 million years, the fish have had a long time to evolve and adapt to the polar water.  Three hundred fish species live in Antarctic waters and 80 are unique to the McMurdo area.  These Antarctic fish express several unique features:
  • Their blood contains antifreeze proteins that prevent ice particles from coalescing
  • Some fish, like the ice fish below, have no hemoglobin (their blood is colorless) but simply dissolve oxygen without an oxygen transport protein 

  • They grow quite slowly.  For example, a two-year-old dragonfish may be only one centimeter long.  The time for dragonfish to reach sexual maturity is thought to be around 20 years (but no one really knows). 
  • They have many more mitochondria to produce energy than the average vertebrate
  • Predators are few so they have few anti-predation strategies.  Also, competitors for food are few so they don't have strategies for that, either.

The fish Anne studies:  Dragonfish, Emerald Rockcod and Bald Notothen
Anne's group sends divers down to collect the juvenile forms of dragonfish and emerald rock cod and then exposes them over a few months to different combinations of water temperature and acidity.  Although much is yet to be learned, it appears these animals simply cannot tolerate the combination of increased temperate and acidification that the Antarctic zone is likely to experience with global warming.  Her conclusions were dire--these fish are likely to be wiped out within the next 50 to 100 years.  Despite how upbeat and joyful Anne is about here research, I left feeling sober.

Comments

Post a Comment

Popular posts from this blog

What we've been up to

Image
Ross Island looking out from the Pegasus crash site on the Ross Ice Shelf.  The peaked mountain is Ob Hill with McMurdo to its left.  Erebus is obscured by clouds.  The two dots halfway between the camera and the island at the left tip of the island are emperor penguins.   Condition:  Temperature 41°F (Windchill 39°).  Mostly cloudy Population = 1141 We've been extremely busy.  We've had several bad injuries on the base, including last week a hand smashed by a 42 ton ship's hatch.  Once again, Dean did an amazing job with the injury but with broken planes and unrested flight crews, the patient ended up spending seven hours in an ambulance waiting on the runway before being brought back to the clinic to wait some more. I was assigned to care for him that evening, re-bandaging his wound twice, giving him his pain meds and antibiotics, helping him shower, and ultimately, putting a squirting hole in his IV tubing AND covering myself ...
Read more

Off the ice

Image
Toto, I think we're not in Kansas anymore Conditions:  Temperature 70° (70° with wind chill).  Sunny. Population=381,500  Well, we got off the ice.  The trip proved somewhat harrowing and prolonged but we are now blissfully ensconced in the Crowne Plaza in Christchurch, heading back home tomorrow. Antarctica is shutting down for the winter. The Pole will close to all transportation in about two weeks just as the sun begins to set, leaving only the 40-50 person overwinter crew behind to face the brutally cold and dark winter.  McMurdo will close more slowly and, for the first time, will actually have winter flights to facilitate the new base construction.  Usually, about 150 people would be left in McMurdo by mid-February.  This year with all the new base construction underway, they expect to winnow down the current 1100 people to about 400in the next 10 days and and then to 300 or so at the end of April and 150 in June. The whole...
Read more

South Pole Traverse

Image
The South Pole Traverse moving down the Leverett Glacier: my dream job. Conditions:  Temperature 19° (4 ° with windchill).  Cloudy.  Population = 1100+ I mentioned in a previous post, the cowboys of the Antarctic are the South Pole Traverse (SPoT) team.  Like Scott and Shackleton, they troop slowly in tractors, pulling necessary supplies--particularly fuel--to the South Pole.  The Pole base could not exist without the traverse; planes simply could not carry enough fuel to supply the base. The eight man crew drives tractors 1031 miles, averaging about 5 miles per hour over 25 12-hour days (it took Amundsen 57 days and Scott 78 to reach the Pole).  The tractors transport diesel fuel in long bladders that drag along the ground. They also pull the team's living quarters.  On the way back, they fill the bladders with air so they drag well and also bring back the waste that needs to be shipped off ice.  Although I think of this as my dream...
Read more