What to do with the humpback that swam into a river full of crocodiles in north-east Australia? That question is now facing the local authorities now that at least one sea creature has migrated no less than 20 kilometres inland. Biologists are faced with a riddle.
The enormous cetacean took a wrong turn during its annual migration to Antarctica and accidentally ended up in the murky, crocodile-forgiven East Alligator River.
Scientists are faced with a riddle, never before have such sea creatures been spotted in the salty river. Nobody understands how it could have happened that the animals went so far into a shallow river. At least three humpbacks were spotted in the river, two swam back to sea of their own accord. What about the third colossus?
The authorities cordoned off part of the river to prevent a collision with the humpback. “The water in the river is extremely cloudy. You don’t actually see anything at all. If you’re on a boat, you only see the humpback when it comes to the surface,” says marine biologist Jason Fowler in Australian media.
Up to 12 metres long
There would be two adult animals and one younger animal. The animals would be between 10 and 12 metres long. According to experts, this size makes it unlikely that crocodiles will attack the animal. If, however, the humpback whale still swimming in the riveri were to strand and become weakened, it is not inconceivable that crocodiles would strike. The humpback has had a long journey and has probably had to swim for days against the current.
The population of Australian humpback whales is said to have exploded in recent years, increasing the risk of stray animals. “They also end up in unexpected places, as we often see. But swimming so far into a murky river is bizarre and unprecedented”
In order to get the animal back to the sea, various options are being considered. For example, the humpback can be driven back by means of a continuous row of boats. By hitting the sides of the boat, the animal would be deterred. Also considered is the spreading of whale sounds under water, in order to lure the animal towards the open sea. Marine biologists once succeeded in San Francisco to get a humpback from a narrow bay. The ‘noise tactic’ was once successfully applied in Tasmania.
For the time being it remains guessing the fate of the stray animal. “I also wonder what will happen during the nights. The humpback will want to rest, but will it be able to if it is surrounded by so many large crocodiles?” Fowler wonders.
For the time being, the authorities are waiting to see what the animal will do. It is hoped that it will swim back to sea itself.