SC/59/BRG23 1 Surprising recovery of bowhead whales
The bowhead whale was severely depleted for several decades of commercial whaling when the species was offered worldwide protection in 1931. No signs of 10 population recovery in West Greenland were observed over the course of the 100-year post-whaling period. In April 2006, a dedicated survey for b...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.532.9399 http://www.iwcoffice.co.uk/_documents/sci_com/SC59docs/SC-59-BRG23.pdf |
| Summary: | The bowhead whale was severely depleted for several decades of commercial whaling when the species was offered worldwide protection in 1931. No signs of 10 population recovery in West Greenland were observed over the course of the 100-year post-whaling period. In April 2006, a dedicated survey for bowhead whales was conducted on the former whaling grounds in efforts to determine the current population status. This effort included a double platform aerial survey design, satellite tracking of the movements of nine whales, and estimation of high resolution 15 surface time from 14 whales instrumented with time-depth recorders. The whales utilized an area of ~25.000 km2 and 32 out of 36 bowhead whale sightings during the survey were within this area. Only 12 % of the area used by the tracked whales was not covered by the survey. The aerial survey sampled 125.634 km2 of bowhead whale habitat with 10.500 km flown. After accounting for perception bias, there were 20 estimated to be 295 animals in the survey area (cv=47%). Using data from the instrumented whales, animals were estimated to spend an average of 24 % (cv=0.03) of the time at or above 2 m depth,, the maximum depth to which bowhead whales |
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