Thursday, November 04, 2004

Pup tally = 97 (90 still alive, 7 dead)

The first week in November is historically when the most seal pups are born, so based on our current numbers, we expect that we will end up with less than 150 pups for the season. Our first population survey for the entire study area will be on Sunday and it will be interesting to know the total number of seals on the study area. With many fewer seals than in past years, the survey will probably go quickly. The sea ice in our study area has not gone out in the past few summers, so is getting thicker each winter (now the ice is about 15 feet thick where our camp is located). The thickness of the ice may be limiting the availability of places for seals to haul out. Some researchers from New Zealand are diving under the ice to study the seaweed and algae at one colony where we had seen no seals yet this year. As soon as they drilled a hole to dive through, a couple young seals began using the hole to haul out.

Tomorrow we'll fly over the study area and make sure that we haven't missed any areas where seals are hanging out. If we see any seals in areas we haven't routinely checked, we'll have a day to go find them and tag them before our first population survey.
Another consequence of the accumulating sea ice is the size of ridges in the ice that build up due to pressure on the sea ice from movement of glaciers. This photo shows the pressure ridge on the SW side of Big Razorback Island. Terra is doing a headstand in the photo for scale.

Part of the research our group is doing involves weighing the Weddell seals, using a big scale that is pulled behind a snowmobile. The scale is also a convenient way to transport crew members around the seal colony, as in this picture of Terra, Jay, and Bob being towed by Kelly in our very own Big Razorback homecoming parade.

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