| Autor: |
Hendricks B; SoundSpace Analytics, Cumberland, British Columbia V0R 1S0, Canada., Keen EM; Marine Ecology and Telemetry Research, 2468 Camp McKenzie Trail Northwest, Seabeck, Washington 98380, USA., Shine C; North Coast Cetacean Society, 26 Cottonwood Road, Alert Bay, British Columbia V0N 1A0, Canada., Wray JL; North Coast Cetacean Society, 26 Cottonwood Road, Alert Bay, British Columbia V0N 1A0, Canada., Alidina HM; Oceans Program, World Wildlife Fund-Canada, 259-560 Johnston Street, Victoria, British Columbia V8W 3C6, Canada., Picard CR; Gitga'at Oceans and Lands Department, 445 Hayimiisaxaa Way, Hartley Bay, British Columbia V0V 1A0, Canada. |
| Abstrakt: |
Fin whale 20 Hz calls were detected, localized, and tracked using a 10 km aperture network of three acoustic receivers deployed for 11 months in a Pacific Canadian fjord system. The area has been historically important for fin whales and is located along a route that tankers will begin using in 2024. A total of 6712 calls were localized, and trajectories were fitted for 55 acoustic tracks. Fin whale tracks occurred throughout the monitoring site. Call activity peaked in September and was low during winter months. Swimming characteristics varied significantly between day- and nighttime: at night, whales swam faster (7.1 vs 4.0 km/h median, +75.2%), which resulted in longer (+34.7%), less predictable (-70.6%) tracks as compared to daylight hours. Call frequencies varied between 16 and 32 Hz. Beside stereotypical song frequencies, fin whales also used irregular frequency components, which contributed the majority of calls in the summer but did not occur in the winter. The results suggest that the area is primarily used as a summer feeding ground, where fin whales follow a diel behavioral cycle. The observed activity patterns will aid in the assessment of strike risk and harassment mitigation and provide a baseline to document behavioral change. |
