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Keen EM, Pilkington J, O’Mahony É, Thompson KL, Hendricks B, Robinson N, Dundas A, Nichol L, Alidina HM, Meuter H, Picard CR, Wray J. Fin whales of the Great Bear Rainforest: Balaenoptera physalus velifera in a Canadian Pacific fjord system. PLoS One 2021; 16:e0256815. [PMID: 34478477 PMCID: PMC8415578 DOI: 10.1371/journal.pone.0256815] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 08/17/2021] [Indexed: 11/19/2022] Open
Abstract
Fin whales (Balaenoptera physalus) are widely considered an offshore and oceanic species, but certain populations also use coastal areas and semi-enclosed seas. Based upon fifteen years of study, we report that Canadian Pacific fin whales (B. p. velifera) have returned to the Kitimat Fjord System (KFS) in the Great Bear Rainforest, and have established a seasonally resident population in its intracoastal waters. This is the only fjord system along this coast or elsewhere in which fin whales are known to occur regularly with strong site fidelity. The KFS was also the only Canadian Pacific fjord system in which fin whales were commonly found and killed during commercial whaling, pointing to its long-term importance. Traditional knowledge, whaling records, and citizen science databases suggest that fin whales were extirpated from this area prior to their return in 2005-2006. Visual surveys and mark-recapture analysis documented their repopulation of the area, with 100-120 whales using the fjord system in recent years, as well as the establishment of a seasonally resident population with annual return rates higher than 70%. Line transect surveys identified the central and outer channels of the KFS as the primary fin whale habitat, with the greatest densities occurring in Squally Channel and Caamaño Sound. Fin whales were observed in the KFS in most months of the year. Vessel- and shore-based surveys (27,311 km and 6,572 hours of effort, respectively) indicated regular fin whale presence (2,542 detections), including mother-calf pairs, from June to October and peak abundance in late August-early September. Seasonal patterns were variable year-to-year, and several lines of evidence indicated that fin whales arrived and departed from the KFS repeatedly throughout the summer and fall. Additionally, we report on the population's social network and morphometrics. These findings offer insights into the dynamics of population recovery in an area where several marine shipping projects are proposed. The fin whales of the Great Bear Rainforest represent a rare exception to general patterns in this species' natural history, and we highlight the importance of their conservation.
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Affiliation(s)
- Eric M. Keen
- North Coast Cetacean Society, Alert Bay, British Columbia, Canada
- Environmental Studies, Sewanee: The University of the South, Sewanee, TN, United States of America
- Environmental Studies, University of Victoria, Victoria, British Columbia, Canada
| | - James Pilkington
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | - Éadin O’Mahony
- North Coast Cetacean Society, Alert Bay, British Columbia, Canada
- Scottish Oceans Institute, University of St Andrews, St Andrews, United Kingdom
| | - Kim-Ly Thompson
- Environmental Studies, University of Victoria, Victoria, British Columbia, Canada
| | - Benjamin Hendricks
- North Coast Cetacean Society, Alert Bay, British Columbia, Canada
- SoundSpace Analytics, Cumberland, British Columbia, Canada
| | - Nicole Robinson
- Gitga’at Oceans and Lands Department, Hartley Bay, British Columbia, Canada
| | - Archie Dundas
- Gitga’at Oceans and Lands Department, Hartley Bay, British Columbia, Canada
| | - Linda Nichol
- Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, British Columbia, Canada
| | | | - Hermann Meuter
- Pacific Whale Society, Hartley Bay, British Columbia, Canada
| | - Chris R. Picard
- Gitga’at Oceans and Lands Department, Hartley Bay, British Columbia, Canada
| | - Janie Wray
- North Coast Cetacean Society, Alert Bay, British Columbia, Canada
- Pacific Orca Society, Alert Bay, British Columbia, Canada
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