At the beginning of September, two humpback whales have been reported unexpectedly high up in the Kakadu East Alligator River of New Zealand. With the humpbacks now a historical 20 kilometres upriver, a 30-kilometre no-boat zone has been established to keep the animals safe and a marine expert team is debating on how to shepherd the whales back towards the sea to decrease the stranding risk.
For the shepherding strategy, the main focus has shifted to auditory cues. One way would be the use of whale calls; either killer whale calls to deter the whales or humpback whale calls to entice them back towards the sea. The second solution considered relies on sound pollution to discourage them from heading further up the river. A formerly successful way would be to bang an object such as a metal rod against a ship’s hull. Either strategy has been shown to work in previous cases but can only be conducted under a 100 per cent safety perspective. For now, the Northern Territory team will try to tag one of the whales to allow monitoring of their movement and thereon base their decision.
Though the two humpback whales are historically far upriver, finding them in unusual places in not unlikely. They are naturally curious animals but tend to get lost easily as they only navigate based on sight and sound. With the humpback whale population significantly increasing in New Zealand’s waters, they might have come further up the coast than usual to explore and finally found themselves lost.
The full article can be found here: https://thenewdaily.com.au/life/science/environment/2020/09/14/humpback-whales-rescue-kakadu/
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