The Department of Biological Sciences Updates

Report from Antarctica; February 2012

       B-232 deployed to McMurdo Station twice during austral summer 2011-2012. Our very successful Oct-November deployment was focused on locating seals we had outfitted with satellite tags in Jan-Feb of 2011, recovering the tags, and collecting measurements of animal health and condition at the start of the breeding season. The primary goal of the Jan - Feb season is to outfit molted Weddell seals with satellite tags to track their overwinter movements and diving behavior, to gather oceanographic data from the tags (temperature and conductivity), and to assess the physiological status of Weddell seals at the end of the molt. This deployment, we also had a PolarTrec teacher, Ms. Alex Eilers, with us for the entire deployment, and a videographer, Jesse Hiatt, with us for a short period from late January to early February. Alex is blogging about our research, providing educational material to lots of schools, and working with us to give online and video conferences about our work. Her blog can be found at http://www.polartrec.com/expeditions/weddell-seals-in-the-ross-sea

       The research has gone very well – we have deployed satellite-linked dive recorders on 5 male and 16 adult female Weddell seals – in four separate locations. Twelve of the tags were deployed on adult females in the immediate vicinity of McMurdo Station (the group of points to the lower right in the figure below). We selected previously flipper tagged adult females in this area to improve our chances of recovering the tags in Oct/Nov, when the seals return to pup. The remaining 9 tags were spread in three groups up the VictoriaLand coast, with the furthest group being approximately 125 km to the north of McMurdo Station. All of the tags are working well so far – but the seals’ winter adventures are just starting.

       We have had some adventures of our own – on two separate occasions when we were working at the furthest north point we ran into bad weather. The first time we were working in great weather, but McMurdo Station was in blowing snow, so the helicopter could not return to base, and we spent the night at Marble Point, a permanent fueling station and small camp about 65 miles from McMurdo. The second time, we were caught in snow and fog (while McMurdo was in sun) and we had to wait in the helicopter for 4 hours until we could see enough to take off and get back to base. We were lucky not to have to camp on the sea ice using our survival bags! Still, most of the time our weather has been great, and adventures such as these remind us why we carry all that extra gear every time we leave base.

       A few other interesting things have happened this season – first, we have noticed that the females that are fully molted are very large and fat in comparison to those that have yet to start molting. This has started us thinking about the interaction between pupping and molting, and we’ve been reading lots of flipper tags to expand the comparison and test whether this observation is backed by real data. If so, there may be some interesting life-history implications that may warrant a follow up study! Of course, seals aren’t the only critters down here molting – we have seen molting Emperor and Adelie penguins too (and nothing looks more miserable than a molting penguin!!) On our last day of tagging seals was a real treat- nice, cooperative seal to tag on a gorgeous sunny day, and an adelie penguin and 5 crabeater seals nearby. Adelie’s are common in the area because there are large colonies nearby, but crabeater seals are rarely found this far south in the heavy ice.   

       We can tell that it is getting close to the time to leave McMurdo Station – the days aren’t getting any shorter (first sunset is not until Feb 21^st), but the light angle is lower on the horizon at night and there is a ton of open water in and around base & many of the locations that we drove snow machines around in October would now require zodiacs to access! So, with all our tags deployed, it is now time to start packing gear and samples for shipping home. We’ll miss the field, but are eager to get home too.

Dr. Jenn Burns

Report from Antarctica; Thursday Jan 12 – Friday Jan 20th

       B-232 is deploying to McMurdo Station twice during austral summer 2011-2012. The primary goal of the Jan - Feb season is to outfit molted Weddell seals with satellite tags to track their overwinter movements and diving behavior, to gather oceanographic data from the tags (temperature and conductivity), and to assess the physiological status of Weddell seals at the end of the molt. We are also working with a PolarTrek teacher this January.

       Our second deployment this summer began on Jan 12, when 5 members of our field team, Kim Goetz (UCSC), Patrick Robinson (UCSC), Jennifer Burns (UAA), Christopher Burns (UAA), and Alice Eilers (PolarTrek) deployed to the ice (Luis Huckstadt followed on Jan 20^th). Good weather delayed our arrival because it made the runway too soft for the C-17 to land; we finally came in on a ski-equipped C-130. Chris and Alex (Alice) immediately started happy camper, and enjoyed great weather for the two days. The rest of the team spent time unpacking the lab and getting gear ready. By the end of this first week, everyone had completed all mandatory training, and we had been out to check the molt status of the seals at the Scott Base Pressure ridges. Thanks to FSTP, a route off the ice shelf onto the sea ice had been prepared for us, and we worked with FSTP to assess the safety of the Ice around the seals. Ice thickness is greater than 1.5m, and we will be working in that area to deploy tags on seals once they are sufficiently molted.

       Following the sea ice training (for Chris and Alex) and route recce (for all of us), we tested the CTD sensors on all the tags we will be deploying on seals. We found a seal hole in the ice off Scott Base, and lowered a CTD and the seal tags together to a depth of 180m. Back in the lab, we have rechecked the tags calibration against the CTD, and ensured that all tags are working properly and ready to deploy on the seals.  This also allowed us to get a CTD cast of the water column at the edge of the ice shelf. A similar cast will be repeated at all locations where tags will be deployed.  During this period, Alex diligently blogged and answered questions posted by the 100’s of students and teachers following her adventures. Check out her blog at http://www.polartrec.com/expeditions/weddell-seals-in-the-ross-sea 

       With all the gear prepped and the access routes found for getting to the seals at the Pressure Ridges and near Turtle Rock, we are waiting for seals to molt sufficiently for us to be able to attach the tags. Seals that we have checked over the past few days are almost ready, but not quite. We have a flight scheduled north early in the week in the hopes that, like the past two years, the seals to the north of Granite Harbor molt a few days earlier than those in Erebus Bay.

Dr. Jenn Burns