Foraging ecology, diving behavior, and migration patterns of harbor seals (Phoca vitulina richardii) from a glacial fjord in Alaska in relation to prey availability and oceanographic features

• Main Author: Womble, Jamie N.
• Other Authors: Horning, Markus, Wright, Dawn J., Epps, Clinton W., Ciannelli, Lorenzo, Fisheries and Wildlife, Oregon State University. Graduate School
• Format: Doctoral or Postdoctoral Thesis
• Language: English; unknown
• Published: Oregon State University
• Subjects: Harbor seal > Alaska > Glacier Bay; Harbor seal > Ecology > Alaska > Glacier Bay; Harbor seal > Migration > Alaska > Glacier Bay; Harbor seal > Behavior > Alaska > Glacier Bay; Harbor seal > Food > Alaska > Glacier Bay; Gulf of Alaska; Glacier Bay; glacier; harbor seal; Phoca vitulina; Alaska
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/pn89d989d

Understanding the movement behavior and foraging strategies of individuals across multiple spatial and temporal scales is essential not only for understanding the biological requirements of individuals but also for linking individual strategies to population level effects. Glacial fjords scattered throughout south-central and southeastern Alaska host some of the largest seasonal aggregations of harbor seals (Phoca vitulina richardii) in the world, and an estimated 15% of the harbor seal population in Alaska is found seasonally at these glacial ice sites. Over the last two decades, the number of harbor seals has declined at two of the primary glacial fjords, in Aialik Bay in south-central Alaska and in Glacier Bay in southeastern Alaska, thus raising concerns regarding the viability of seal populations in glacial fjord environments. From 2004-2009, the foraging ecology, diving behavior, and migration patterns of harbor seals from Glacier Bay National Park, Alaska were examined in relation to prey availability and oceanographic features in Glacier Bay and the surrounding regions of southeastern Alaska. Time-depth recorders, very high frequency transmitters, and satellite-linked transmitters were used to quantify the vertical and horizontal movement patterns of harbor seals in the marine environment. Specifically, (1) I characterized the diving behavior, foraging areas, and foraging strategies of female harbor seals from terrestrial and glacial ice sites relative to prey availability during the breeding season (May-June) in Glacier Bay, (2) I quantified the intra-population variation in at-sea post-breeding season (September-April) distribution and movement patterns of female harbor seals in relation to oceanographic features, (3) I quantified the post-breeding season migration patterns of female harbor seals relative to the boundaries of the marine protected area of Glacier Bay National Park, and (4) I characterized the use of the continental shelf region of the eastern Gulf of Alaska by female harbor seals from ...