CANBERRA, Australia – Marine authorities were puzzling Monday over how to persuade at least one wayward humpback whale to leave a murky, crocodile-infested river in northern Australia and continue an annual migration to Antarctica.
There have been no previous recorded sightings of whales in East Alligator River in the Northern Territory's World Heritage-listed Kakadu National Park, and no one can explain why at least three of the blue water mammals ventured so deep inland in a river with little visibility.
Marine ecologist Jason Fowler said he spotted three whales on Sept. 2 while sailing with friends more than 12 miles from the river's mouth.
“We happened to bump into some great big whales which completely blew me away,” Fowler said Monday.
“The water's incredibly murky. It's got zero visibility. So you can only see the whales when they're right on the surface,” he said.
Fowler estimated that there were two adults and a younger whale in the river, about 33 feet to 39 feet long.
“The west Australian humpback whale population has absolutely exploded. It's the great conservation success story in the ocean,” Fowler said.
Despite the river's name, there are no alligators in Australia. It was named after its many crocodiles by European explorers who apparently couldn't tell the difference.
Northern Territory government whale and dolphin scientist Carol Palmer said there was at least one whale still in the river over the weekend.
“We don't know what's happened, but it's obviously made a wrong turn and ended up in the East Alligator River,” Palmer said.
Options to persuade the whale to leave the river included using recorded whale calls or creating noise by banging the side of boats.
Whale call recordings have been used successfully to entice a humpback whale out of San Francisco Bay.