USAP-DC

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 will 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). For each group of females, physiology and behavior during the nursing period will be analyzed to assess whether investments influence their probability of reproducing the following year. Whole genomes will be compared between groups to identify underlying genes that govern reproductive success and population stability in a long-lived mammal. This collaborative project will provide research opportunities and training to several undergraduate and graduate students at the three participating 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. Within any wild animal population there is substantial heterogeneity in reproductive rates and animal fitness. Not all individuals contribute to the population equally; some are able to produce more offspring than others and thus are considered to be of higher quality. This study aims to distinguish which physiological mechanisms (energy dynamics, aerobic capacity, and fertility) and underlying genetic factors make some Weddell seal females particularly successful at producing pups year after year, while others produce far fewer pups than the population average. In this project, an Organismal Energetics approach will identify key differences between high- and low-quality females in how they balance current and future reproductive success by tracking lactation costs, midsummer foraging success and pregnancy rates, and overwinter foraging patterns and live births the next year. Repeated sampling of individuals' physiological status (body composition, endocrinology, ovulation and pregnancy timing), will be paired with a whole-genome sequencing study. The second component of this study uses a Genome to Phenome approach to better understand how genetic differences between high- and low-quality females directly correspond to functional differences in transcription, translation, and ultimately phenotype. This component will contribute to the functional analysis and annotation of the Weddell seal genome. In combination, this project will make strides towards distinguishing the roles that plastic (physiological, behavioral) and fixed (genetic) factors play in complex, multifaceted traits such as fitness in a long-lived wild mammal. The project partners with established programs to implement extensive educational and outreach activities that will ensure wide dissemination to educators, students, and the public. It will contribute to a marine mammal exhibit at the Pink Palace Museum, and a PolarTREC science educator will participate in field work in Antarctica. This award is co-funded by the GEO-OPP-Antarctic Organisms and Ecosystems Program, BIO-IOS-Physiological Mechanisms and Biomechanics Program, and the Established Program to Stimulate Competitive Research (EPSCoR). This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Person	Role
Shero, Michelle	Investigator and contact
Hindle, Allyson	Co-Investigator
Burns, Jennifer	Co-Investigator
Briggs, Brandon	Co-Investigator

Antarctic Organisms and Ecosystems

Award # 1853377

USAP-1853377_1

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	Weddell seal iron dynamics and oxygen stores across lactation	None	exists
USAP-DC	Weddell seal dive behavior and rhythmicity from 2010-2012 in the Ross Sea	Comma-Separated Values (CSV)	exists

1. Iron mobilization during lactation reduces oxygen stores in a diving mammal (doi:10.1038/s41467-022-31863-7)