A field comparison of marine mammal detections via visual, acoustic, and infrared (IR) imaging methods offshore Atlantic Canada

TitleA field comparison of marine mammal detections via visual, acoustic, and infrared (IR) imaging methods offshore Atlantic Canada
Publication TypeJournal Article
Year of Publication2020
AuthorsSmith, Heather R., Zitterbart Daniel P., Norris Thomas F., Flau Michael, Ferguson Elizabeth L., Jones Colin G., Boebel Olaf, and Moulton Valerie D.
JournalMarine Pollution Bulletin
Volume154
Pagination111026
ISBN Number0025-326X
EndNote Rec Number13047
KeywordsDetection methods, Infrared (IR) imaging, marine mammal, Observer experience, passive acoustic monitoring (pam), Seismic survey
Abstract

Impulsive sounds generated during seismic surveys have elicited behavioral responses in marine mammals and could cause hearing impairment or injury. Mitigating exposure to seismic sound often relies on real-time marine mammal detection. Detection performance is influenced by detection method, environmental conditions, and observer experience. We conducted a field comparison of real-time detections made by marine mammal observers (MMOs), a rotating infrared (IR) camera, and via passive acoustic monitoring (PAM). Data were collected from a 38 m research vessel offshore Atlantic Canada. Our results indicate that overall detection rates increase when complementary methods are used. MMOs and PAM are likely the most effective combination during high seas and precipitation. PAM and IR can be used in darkness. In good visibility, MMOs with IR or PAM should increase detections. Our results illustrate the importance of addressing false positive IR detections, matching system capabilities to sea conditions/species of interest, and employing experienced observers.