Dive and surfacing characteristics of bowhead whales ( Balaena mysticetus ) in the Beaufort and Chukchi seas

• Published in: Canadian Journal of Zoology
• Main Authors: Krutzikowsky, Gregory K, Mate, Bruce R
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2000
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Balaena mysticetus; Chukchi
• Online Access: http://dx.doi.org/10.1139/z00-046; http://www.nrcresearchpress.com/doi/pdf/10.1139/z00-046

We received data from eight bowhead whales (Balaena mysticetus) equipped with satellite-monitored radio tags for 3-33 days. Of 42 306 dives made by the eight whales during 1695 h, 9573 were sounding dives (>1 min duration). The mean duration of sounding dives for individuals varied from 6.9 to 14.1 min (mean = 10.4 ± 2.4 min, n = 8). Five whales made dives [Formula: see text]61 min; the longest dives for the other three lasted 56, 45, and 32 min. Five tags measured maximum depths of 29 499 dives during 1220 h and time at depth during 1228 h. All five whales dived >100 m; the deepest dive was 352 m. Whales spent most of their time at depths [Formula: see text]16 m, but three whales spent most of their time at depths >48 m during some sampling periods. Mean surfacing rates ranged from 18.2 to 47.0/h (mean = 26.2 ± 9.0/h, n = 8). Tags were exposed to air for 4.0-7.3% of the time (mean = 5.5 ± 0.95%, n = 8), and whales were potentially visible from aircraft for 8.5-16.4% of the time (mean = 11.1 ± 2.4%, n = 8). Three whales made longer sounding dives and had lower surfacing rates when in [Formula: see text]90% ice cover. No consistent diel patterns were found.