Marine experts are planning to rescue humpback whales that have been recorded for the first time in crocodile-infested waters in the Kakadu national park in tropical northern Australia. It is thought the giant sea mammals took a wrong turn during one of nature’s most epic migrations.
The humpbacks should be starting their long journey to Antarctica from breeding grounds off Western Australia’s remote north coast. Instead, a small group – thought to be two adults and a large juvenile – were spotted in the East Alligator river in the Kakadu national park, east of Darwin on September 2. It is famous for its world heritage Aboriginal rock art and for its crocodiles. Never have migrating whales been recorded in the area.
Experts believe one of the humpbacks has returned to the sea, and plans are being made to coax the others to follow. This could involve using the noise from boat engines to gently move them down the river towards Van Diemen’s Gulf that leads to the open waters of the Timor Sea off northern Australia. Whale calls and songs might also be used to try to move the humpbacks back into safer waters. Scientists also hope to fit satellite tracking devices to the mammals.
Dr. Carol Palmer, a senior dolphin and whale scientist at the Northern Territory government, says it was extraordinary to see the humpbacks so far inland.
“We went up the East Alligator (river), we were turning around, we went up about 30kms and then as we were just moseying on down, what did we see the humpback whales. Everyone, including myself, we were just really shocked. It is something that has never been recorded before,” Palmer said.
Tens of thousands of humpback whales migrate up and down Australia’s east and west coasts each year. This migration from Antarctica begins around April, when the giant mammals head north to breed. They start heading south in September and November.
Scientists have not yet explained why a small group wandered so badly off-course, ending up in crocodile-infested waters in the Northern Territory. Saltwater crocodiles are the world’s largest reptiles. They are aggressive and dangerous but are thought to pose little danger to the whales unless the humpbacks become stranded on a sandbank.