Killer whale use of the inside waters of Vancouver Island, British Columbia
department or school: Science, Faculty of
department or school: Zoology, Department of
data provider: DSpace
degree campus: UBCV
creator: Scarff, Taryn M.
issued: 2025-04-30T07:00:00Z
issued: 2024
related degree: Master of Science - MSc
degree grantor: University of British Columbia
description: Killer whales (Orcinus orca) play an important role in the coastal ecosystems of British Columbia. In recent decades, west coast transient and southern resident killer whales (two of the main ecotypes of killer whales in BC) have changed their use of coastal BC waters. However, seasonal abundance and distribution changes, and reasons for why the changes occurred remain relatively unknown. I used sighting reports of transient and southern resident killer whales from 2016-2023 in the inside waters of Vancouver Island (the Salish Sea and North Island Waters) to evaluate how these ecotypes use the area, and the relative importance of the area to their populations. I determined the proportion of the BC west coast transient killer whale population that use the inside waters and compared these results with southern resident killer whale seasonal variation in occupancy to analyze the difference in use of the Salish Sea between the two ecotypes. I found that approximately 70% of the BC west coast transient population uses the inside waters annually. Transient killer whales were present in the inside waters year-round, with seasonal highs from March-September each year, which corresponded with the presence of prey species that are drawn to the area during times that key fish species spawn. I also discovered an odd vs. even year pattern in transient killer whale presence where transient abundance varies in July of alternating years, which may be related to the return of pink salmon. Southern residents were not observed consistently throughout the year in the Salish Sea and had a fluctuating seasonal presence that peaked in March, July, September and November. These peaks also corresponded with spawning times of key fish species that southern residents rely on for prey. Overall, my results show that the inside waters of Vancouver Island are important for both ecotypes of killer whales, and that their presence in the area relates to spawning seasons of key fish species. These fi…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/87724
note: KILLER WHALE USE OF THE INSIDE WATERS OF VANCOUVER ISLAND, BRITISH COLUMBIA by Taryn M. Scarff B.Sc., The University of British Columbia, 2020 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Zoology) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) April 2024 © Taryn M. Scarff, 2024 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled: Killer Whale Use of the Inside Waters of Vancouver Island, British Columbia submitted by Taryn M. Scarff in partial fulfilment of the requirements for the degree of Master of Science in Zoology Examining Committee: Dr. Andrew Trites, Professor, Institute for the Oceans and Fisheries, UBC Supervisor Dr. David Rosen, Assistant Professor, Institute for the Oceans and Fisheries, UBC Supervisory Committee Member Dr. Kaitlyn Gaynor, Assistant Professor, Department of Zoology, UBC Additional Examiner iii Abstract Killer whales (Orcinus orca) play an important role in the coastal ecosystems of British Columbia. In recent decades, west coast transient and southern resident killer whales (two of the main ecotypes of killer whales in BC) have changed their use of coastal BC waters. However, seasonal abundance and distribution changes, and reasons for why the changes occurred remain relatively unknown. I used sighting reports of transient and southern resident killer whales from 2016-2023 in the inside waters of Vancouver Island (the Salish Sea and North Island Waters) to evaluate how these ecotypes use the area, and the relative importance of the area to their populations. I determined the proportion of the BC west coast transient killer whale population that use the inside waters and compared these results with southern resident killer whale seasonal variation in occupancy to analyze the difference in use of the Salish Sea between the two e…
has type: Thesis/Dissertation
date issued: 2024-05
is shown at: 10.14288/1.0441015
language: eng
degree discipline: Zoology
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Trites, Andrew W., 1957-
type: Text
identifier URI: http://hdl.handle.net/2429/87724