It’s not easy to count whales! Scientists use aerial surveys to accomplish this arduous task. Whales are visible from the air when they come to the surface to breathe. They don’t stay very long, however. On average they spend between 40% and 80% of their lives beneath the surface.
Method used to count whales:
- Researchers fly over a part of the territory where the whales live following a precise route (systematically or in a random manner, depending on the method chosen) preferably on a windless day with excellent visibility.
- A camera attached to the underside of the airplane takes pictures of the water’s surface at regular intervals.
- Back at the lab, researchers count the whales visible on each frame.
- To obtain an estimate, adjustments are made to the number of whales counted in each frame to take into account sectors that were not covered. Corrections are then made to account for animals that had dived and were not photographed when the airplane passed over them.
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