Using harbor seal whiskers to track seasonal diets
Harbor seals are important predators in coastal ecosystems, yet understanding their diet throughout the year remains challenging. Traditional methods, such as scat analysis, provide only a snapshot of recent feeding and may overlook seasonal changes in prey use.
In this project, we use a novel multi-isotope approach to investigate harbor seal diet by combining stable isotopes of carbon (δ¹³C), nitrogen (δ¹⁵N), and sulfur (δ³⁴S) measured in harbor seal whiskers. This keratinous tissue grows continuously, preserving a chronological record of feeding that allows us to reconstruct dietary patterns over extended periods and evaluate how prey use changes across seasons.
By providing a year-round perspective on harbor seal feeding ecology, this research will improve our understanding of predator–prey interactions in the Northern California Current. More broadly, it demonstrates how multi-isotope techniques can advance ecological studies of marine predators and inform ecosystem-based management.
This project is supported by the Oregon Gray Whale License Plate fund.
Project Lead: Clarissa Teixeira
Collaborators: Elizabeth Daly (NOAA), David Huff (NOAA), Brian Burke (NOAA)
