18 November, 2000

Gone Fishing

All the Herc flights today were sent to Amundsen-Scott Station at the South Pole for fuel delivery. No flights are made on Sundays so it looks like Monday will be our next chance to get to Siple Dome.

The main science facility at McMurdo Station is the Crary Lab. Our project has an office and large lab assigned to us while we are in town. Next door is the office of a team that is studying Antarctic fish. Their interest is focused on a species known as Dissostichus mawsoni. It is named for the renowned Australian polar explorer, David Mawson. The fish is also known as the Antarctic Cod or toothfish.

Bob Hawley and Gary Clow accompanied our neighbors on a fishing excursion last evening. They drove out onto the sea ice to a small hut. Inside the hut, a hole had been drilled through the ice. The ice is about 2.5 meters (8 ft) thick. Below is the water of McMurdo Sound with a depth of 450 meters (1476 ft). They baited thirty hooks with small fish, then lowered the line all the way to the bottom. When it was pulled up, they had caught four Antarctic Cod.

The temperature of the seawater is about -2C (28F), cold enough to freeze the blood of a normal fish. Antarctic fish have a unique adaptation that allows them to survive the cold. A special substance called antifreeze glycoprotein allows the blood to remain liquid even at such low temperatures.

Bob has a 30kg (65lb) Antarctic Cod.

The fish are kept alive and transported back to the aquarium at McMurdo.

Some of the fish end up on the dissection table. The filets are saved and sent to the galley. I had some at a barbeque this evening and it was quite good.

Bob took this image of an Antarctic Cod fish scale using a microscope. The number of lines in the pattern indicates the age of the fish, somewhat like tree rings. The fish that donated this scale was about fifteen years old.