ESR 53:439-466 (2024)  -  DOI: https://doi.org/10.3354/esr01314

ABSTRACT: Several beaked whale species occur off eastern Canada. However, except for the northern bottlenose whale (NBW; Hyperoodon ampullatus), their distribution and annual occurrence remain largely unknown, which complicates management efforts to assess the status of poorly known species and effectively protect those species considered at risk. The main objective of this paper is to provide a year-round and pluriannual description of the minimum acoustic occurrence of the NBW, Sowerby’s (SBW; Mesoplodon bidens), Cuvier’s (CBW; Ziphius cavirostris), True’s (TBW; M. mirus) and Gervais’ (GBW; M. europaeus) beaked whales. Twenty-five acoustic recorders were deployed off eastern Canada between May 2015 and November 2017. Beaked whale echolocation clicks were detected using a combination of automated detectors and manual validation at 12 of these stations. Detections were generally restricted to deep continental slope waters. All detected species occurred in the southern part of the study area (off the Scotian Shelf and southern Grand Banks), while only NBWs were detected at the northern edge, off southern Labrador. Clicks identified as TBW or GBW were restricted to, but occurred annually in, the southern areas. All other species were present, at least seasonally, east and north of the Grand Banks. NBWs occurred every day in the Gully Canyon, where SBWs also occurred regularly. While these results should be interpreted as minimum species presence and considered with regards to detector performance, they provide important information regarding beaked whales’ use of areas off eastern Canada where these species have generally received no or very limited monitoring effort.

KEY WORDS: Acoustic occurrence · Northern bottlenose whale · Cuvier’s beaked whale · Sowerby’s beaked whale · True’s beaked whale · Gervais’ beaked whale · Eastern Canada

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Cite this article as: Delarue JJY, Moors-Murphy HB, Kowarski KA, Maxner EE, Davis GE, Stanistreet JE, Martin SB (2024) Acoustic occurrence of beaked whales off eastern Canada, 2015–2017. Endang Species Res 53:439-466. https://doi.org/10.3354/esr01314 Export citation Share:    Facebook - - linkedIn