Date of Award

12-2025

Document Type

Thesis

Degree Name

Master of Science (MS)

Degree Statement

Master of Science in Wildlife Biology & Conservation

Department

Department of Wildlife Biology & Conservation

Committee Chair

Brinkman, Todd

Committee Chair

Hauser, Donna

Committee Member

Von Duyke, Andrew

Committee Member

Candler, Ellen

Table of Contents

Chapter 1: Introduction 

Chapter 2: Methods

2.1 Study area

2.2 Study design

2.3 Time-lapse camera and weather data processing

2.4 Haul out area substrate analysis

2.5 Modeling environmental and temporal effects on seal counts

2.6 Environmental observations rooted in Indigenous Knowledge

Chapter 3: Results

3.1 Summary of seal counts and weather conditions

3.2 Haul out area availability

3.3 Effects of environmental conditions and temporal variation on spotted seal counts

3.4 Alaska Arctic Observatory and Knowledge Hub community-based observations

Chapter 4: Discussion

4.1 Impacts of substrate availability and environmental conditions on spotted seal terrestrial haul out behavior

4.2 Understanding spotted seal seasonal and interannual presence at terrestrial haul outs

4.3 Spotted seal terrestrial haul out behavior in a changing Arctic

4.4 Conclusion.

Abstract

Hauling out - the act of exiting the water to rest, molt, breed, and pup on solid surfaces - is a key behavior of pinnipeds worldwide. Unlike other ice seals (i.e., ice-associated phocid species), spotted seals (Phoca largha) in Alaska frequently use terrestrial substrates to haul out during the summer and fall open-water period in the Chukchi and Beaufort Seas. Despite being a core aspect of spotted seal ecology, their terrestrial haul out behavior remains understudied. To address this, we analyzed data collected from 2020 - 2022 near two known haul out sites in Dease Inlet, Alaska, including time-lapse camera imagery, weather and environmental data, and observations based in Indigenous Knowledge (IK). We fit generalized additive models for each site to examine how environmental and temporal covariates explain variation in spotted seal counts. Substrate availability was assessed by aligning wind speed and direction data with time­ lapse images that showed exposed or submerged substrate. We found that temperature, day-of- year, year, wind speed, and wind direction best explained variation in seal counts, with wind effects on substrate availability varying by location. Observations from IK holders put seal monitoring results into a broader environmental context, highlighting the role of ice and weather conditions on seasonal and interannual variability in summer and fall haul out behavior. These findings improve understanding of spotted seal ecology during the open-water period and demonstrate how aligning information from different knowledge systems can strengthen results. Furthermore, these results can be used to shape future survey and management efforts, ensuring effective spotted seal conservation in a rapidly changing Arctic.

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