2022-2023 USAP Field Season
Collaborative Research: Physiological and genetic correlates of reproductive success in high- versus low-quality Weddell seals
Dr. Michelle Rebecca Shero
Supporting Stations: McMurdo Station
MAYBE REMOVE FROM 2023-24 Within any population, some individuals perform better than others. These individuals may survive longer or produce more offspring. Weddell seals in Erebus Bay, Antarctica, provide an unparalleled opportunity to investigate how an animal’s physiology, behavior, and genetic make-up contribute to lifetime reproductive success because they have been the subject of a long-term population monitoring study and are easily accessible during their reproductive season. This project aims to distinguish key differences in energy allocation, reproductive timing, and dive capacities between female Weddell seals with a history of frequently producing pups (‘high-quality’ group), versus females that have produced pups only infrequently (‘low-quality’ group). This project will provide research opportunities and training to several undergraduate and graduate students at three collaborating institutions. Results will be broadly disseminated through presentations and peer-reviewed publications, and to students via an extensive public outreach collaboration with museum programming, curriculum-aligned science lessons, and pedagogy training.
Field Season Overview
The major field efforts for this project are: to assess animal physiological condition and dive behavior at the 1) early pregnancy, 2) beginning of lactation, 3) end of lactation, and 4) just after weaning their pups. A field team of nine participants will be based out of McMurdo Station and will take daily trips onto the sea ice to locate specific adult female Weddell seals. They will measure the female and pup's health and condition, equip them with tags that will monitor diving patterns and aid in relocation, and collect samples for genetic analysis. Trips will be by snow machine, with gear towed in sleds. Field activities will include ultrasonography, attaching Time Domain Reflectometry (TDR) and Very High Frequency (VHF) devices to flippers, weight and morphometric measurements, and collecting blood, milk, and tissue samples. Controlled substances will be used to sedate seals, and they will be administered tritiated water (HTO, radioisotope) for body composition analyses. The group will use Crary laboratory space to process and analyze samples. They will use the radioisotope lab to store and prepare aliquots of HTO.
Deploying Team Members