2017-2018 USAP Field Season
Growing up on ice: Physiological adaptations and developmental plasticity in Weddell seal pups across two extreme physical environments
Dr. Heather E Liwanag
California Poly State University
Project Web Site:
Supporting Stations: McMurdo Station
A large body and thick blubber keep Weddell seals warm on and under the ice. Their streamlined shape, oxygen storage capacity, and collapsible lungs allow them to reach depths of 600 meters and remain under water for over an hour. At birth, however, they have small bodies and virtually no blubber. Their oxygen storage capacity is similar to other small terrestrial mammals and they must develop diving capabilities over time. There is likely a trade-off in terms of energy allocated to thermoregulation or to development. Researchers seek to answer the following questions: (1) How do these animals develop the capacity to transition, in a matter of weeks, above, and then below, the Antarctic sea ice? and (2) What are the energetic trade-offs associated with the developmental period during the transition?
Field Season Overview
The team will be housed at McMurdo Station and will make day trips by Pisten Bully and snowmobile to their field sites on the sea ice in Erebus Bay, where they will have a heated fish hut near Turtle Rock. They may also work conduct some sampling at Hutton Cliffs, where they would have an Apple portable shelter. They will use a GroDome tent as a mobile processing station for seal pups that are beyond reasonable sledging distance from the fish hut. The team will access water through cracks or holes in the sea ice. If they cannot find suitable cracks, they will drill holes with a gas-powered Jiffy drill. Over the course of their time on the ice they will conduct some of their work in the Crary Lab. Their work will record mass and morphometrics of the pups. To that end, they will use a forward looking infrared (FLIR) camera to quantify surface body temperature, and an ultrasound machine to measure blubber thickness. They will place pups in a chamber outfitted with analytical equipment to measure metabolic rates. The chamber will be filled with seawater so the pup will be partially submerged. For some sampling events, the group’s veterinarian will anesthetize the pups for the collection of blood and muscle biopsies. Additionally, pups will be tagged with an accelerometer / transmitter / time-depth-recorder device at early capture time points.
Deploying Team Members