Drowned Out: How Marine Vessel Noise Impacts the Southern Resident Killer Whale Population in the Salish Sea

The endangered Southern Resident killer whale (SRKW) population that consists of a total of 73 members, concentrates in the Salish Sea off the coast of British Columbia, Canada and Washington, USA during the summer. The Salish Sea is also an area of high human occupancy and activity, resulting in hi...

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Bibliographic Details
Main Author: Andress, Alyssa
Format: Thesis
Language:English
Published: 2020
Subjects:
Online Access:http://hdl.handle.net/1974/27793
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Summary:The endangered Southern Resident killer whale (SRKW) population that consists of a total of 73 members, concentrates in the Salish Sea off the coast of British Columbia, Canada and Washington, USA during the summer. The Salish Sea is also an area of high human occupancy and activity, resulting in high amounts of marine vessel traffic. The noise created by vessel traffic can negatively affect SRKW life processes, which threatens the small population’s survival. The purpose of this paper is to determine how marine vessel noise affects the SRKW population as well as how commercial and whale watching vessels specifically affect SRKW, as they are notable industries in the area. Another objective is to assess how affective current SRKW-specific legislation is. An examination of published journal articles, theses, and other literature reveals that vessel noise originates from multiple characteristics of a vessel such as length, size, propeller cavitation, distance, and speed. Whale watching vessel noise is mainly due to certain practices such as leapfrogging which increases noise levels near pods, masking SRKW communication. Additionally, commercial shipping vessels increase background noise, masking SRKW calls, and interfering with echolocation. Vessel noise affects SRKW social behaviour including the reduction of SRKW communication space, vessel noise masking SRKW calls, SRKW decreased detection of calls, altering calls, and increased surface active behaviours. Vessel noise disrupts SRKW echolocation and navigation of prey, reduces the amount of resting and foraging time, causes avoidance behaviour, and decreases energy production. SRKW can also suffer from hearing loss due to the constant exposure of vessel noise. This constant exposure to vessel noise can also lead SRKW to permanently abandon their habitat. Current Canadian and American SRKW legislation such as the Oceans Protection Plan and the Species at Risk Act establish protection zones, fines for violating SRKW critical habitat zones, and voluntary vessel ...