Date of Award

12-2025

Document Type

Thesis

Degree Name

Master of Science (MS)

Degree Statement

Master of Science in Marine Biology

Department

Department of Marine Biology

Granting Institution

University of Alaska Fairbanks

Committee Chair

Hollmen, Tuula

Committee Member

Breed, Greg

Committee Member

Danielson, Seth

Committee Member

Gorman, Kristen

Table of Contents

Chapter 1: General introduction

1.1 Species overview

1.2 Association with Fjord habitats

1.3 Nesting habits

1.4 Thesis motivation: associations between nesting and marine foraging

1.5 Literature cites

1.6 Figures and tables

Chapter 2: Kittlitz's murrelet (Brachyramphus brevirostris) marine habitat selection - change over time and contributions of terrestrial habitat proximity

2.1 Abstract

2.2 Introduction

2.3 Methods

2.3.1 Study site

2.3.2 Terrestrial habitat analysis

2.3.3 Oceanography

2.3.4 Marine bird surveys

2.3.5 Habitat selection modeling

2.3.6 Model evaluation

2.4 Results

2.4.1 Terrestrial habitat change

2.4.2 Principal component analysis

2.4.3 Change in oceanography over time

2.4.4 Resource selection function

2.5 Discussion

2.5.1 Terrestrial habitat on marine distribution

2.5.2 Effects of terrestrial habitat on marine distribution

2.5.3 Limitations of terrestrial habitat model

2.5.4 Changes in oceanography over time

2.6 Conclusion

2.7 Ethics statement

2.8 Literature cited

2.9 Figures and tables

Chapter 3: What is the specific relationship between tidewater glacier oceanography and Kittlitz's murrelet (Brachyramphus brevirostris) foraging habitat?

3.1 Abstract

3.2 Introduction

3.3 Methods

3.3.1 Study area

3.3.2 Bird surveys

3.3.3 Acoustic fisheries surveys

3.3.4 Oceanography

3.4 Analysis

3.4.1 Oceanography

3.4.2 Spatial extrapolation of oceanographic variables

3.4.3 Fish analysis

3.4.4 Relationship between forage fish school depth and turbidity

3.4.5 Fish distribution modeling

3.4.6 Density surface modeling

3.5 Results

3.5.1 Influence of turbidity on school depth

3.5.2 Influence of oceanographic conditions and prey distribution on Kittlitz's murrelet distribution

3.6 Discussion

3.7 Conclusion

3.8 Ethics statement

3.9 Literature cited

3.10 Figures and tables

Chapter 4: General conclusions

4.1 Literature cited.

Abstract

The Kittlitz’s Murrelet (Brachyramphus brevirostris) is a rare and cryptic seabird species that inhabits Alaska and Eastern Siberia. Populations of Kittlitz’s Murrelets that occur in areas with tidewater glaciers are tightly associated with tidewater glaciers and are only found in close proximity to them. The Kittlitz’s Murrelet is a species of conservation concern, but specific habitat associations are poorly understood. I conducted a multidisciplinary investigation to better understand associations between Kittlitz’s Murrelets and tidewater fjord physical structure. I used remotely sensed spectral indices to model change in abundance of suitable nesting habitat, and a long-term oceanographic dataset to quantify changes in fjord hydrography over the same time-period. Lastly, I conducted concurrent oceanographic, hydroacoustic fisheries surveys, and seabird surveys to examine the relationship between glacially influenced water column attributes, prey accessibility, and abundance of forage fishes. I found that the amount of suitable nesting habitat in the study area increased by 65%, and the average elevation of suitable nesting habitat increased marginally (67 m). Change in Kittlitz’s Murrelet distribution was correlated with changes in water column stratification over a 16-year period but not change in distance to closest suitable nesting habitat. Turbidity did not influence the depth of forage fish schools (adjusted R- squared = 0.06), but a higher number of forage fish schools were found in more turbid areas (adjusted R-squared = 0.68). Kittlitz’s Murrelet distribution was influenced by forage fish distribution. Modeled relationships between Kittlitz's Murrelets and oceanographic variables revealed that change in marine distribution is not due to change in turbidity or fish school abundance but may be due to change in salinity or temperature.

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