Streaming Media
Presentation Abstract
The Robson Bight Michael Bigg Ecological Reserve (RBMBER) is located within the Northern Resident killer whale (NRKW) population’s critical habitat. A recognized social behaviour of the NRKW population is “beach rubbing”, where individuals will come into the shallows of particular beaches to rub their bodies on smooth pebbles. During beach rubbing, the whales are considered to be more sensitive to disturbance. The physical presence of vessels, as well as the noise from vessel engines has the potential to disturb NRKW and interfere with this sensitive behaviour. To reduce the likelihood of disturbance and protect this important cultural behaviour, recreational vessel traffic is restricted from entering the RBMBER. To assess the potential impacts from vessels on beach rubbing behaviour, we evaluated the vocal repertoire associated with beach rubbing and compared the vocalizations to data from non-rubbing beach recorders. The source level of calls from within and outside the reserve were then measured to examine the effect of vessel noise on rubbing beach vocalizations. Acoustic and visual data were collected between July and September 2021 using acoustic recorders, and behavioural assessments were conducted from an observatory with visual line of sight to three rubbing beaches. A theodolite was used to provide precise measurements on the proximity of vessels to both the whales and the beach. We tested the hypotheses that NRKW use social call types during beach rubbing, and that vessel noise has a greater impact on these vocalizations outside of RBMBER compared to inside RBMBER. This knowledge will help inform policy on the RBMBER’s current marine restrictions and coverage to mitigate future vessel noise stressors on the NRKW population. The data from RBMBER will support advice for the development of acoustic sanctuaries in the Salish Sea to protect the endangered Southern Resident killer whale population from acoustic and physical disturbance.
Session Title
Poster Session 2: The Salish Sea Food Web and Cycles of Life
Conference Track
SSE14: Posters
Conference Name
Salish Sea Ecosystem Conference (2022 : Online)
Document Type
Event
SSEC Identifier
SSE-posters-182
Start Date
26-4-2022 4:30 PM
End Date
26-4-2022 5:00 PM
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Type
Text
Language
English
Characterization of Northern Resident killer whale (Orcinus orca) call types and source levels during beach rubbing
The Robson Bight Michael Bigg Ecological Reserve (RBMBER) is located within the Northern Resident killer whale (NRKW) population’s critical habitat. A recognized social behaviour of the NRKW population is “beach rubbing”, where individuals will come into the shallows of particular beaches to rub their bodies on smooth pebbles. During beach rubbing, the whales are considered to be more sensitive to disturbance. The physical presence of vessels, as well as the noise from vessel engines has the potential to disturb NRKW and interfere with this sensitive behaviour. To reduce the likelihood of disturbance and protect this important cultural behaviour, recreational vessel traffic is restricted from entering the RBMBER. To assess the potential impacts from vessels on beach rubbing behaviour, we evaluated the vocal repertoire associated with beach rubbing and compared the vocalizations to data from non-rubbing beach recorders. The source level of calls from within and outside the reserve were then measured to examine the effect of vessel noise on rubbing beach vocalizations. Acoustic and visual data were collected between July and September 2021 using acoustic recorders, and behavioural assessments were conducted from an observatory with visual line of sight to three rubbing beaches. A theodolite was used to provide precise measurements on the proximity of vessels to both the whales and the beach. We tested the hypotheses that NRKW use social call types during beach rubbing, and that vessel noise has a greater impact on these vocalizations outside of RBMBER compared to inside RBMBER. This knowledge will help inform policy on the RBMBER’s current marine restrictions and coverage to mitigate future vessel noise stressors on the NRKW population. The data from RBMBER will support advice for the development of acoustic sanctuaries in the Salish Sea to protect the endangered Southern Resident killer whale population from acoustic and physical disturbance.
