Mass beaches – why whales lose orientation

In February, more than 150 small whales swam on a remote beach of Tasmania. The fact that whales strand on the coasts of the Australian island always occurs. But the drama of the small sword whales was the first mass beaching of the species in Tasmania for around 50 years. None of the marine mammals survived the disaster. Many died, at least 65 had to be killed.

Attempts to bring the animals back to the sea up to 1300 kilos had failed due to the difficult weather conditions. »The sea conditions had not allowed animals to overcome the surf. The animals stranded again and again, «says Shelley Graham from the Tasmanian Sea Protection Program. Therefore, a killing of the whales was inevitable. The marine biologist Kris Carlyon from the Tasmanian Office for Sea Protection emphasized: »The longer these animals are stranded, the longer they suffer. All alternative options were unsuccessful. Euthanasia is always the last way out. “

The small sword whale is a type of dolphin that forms schools of an average of ten to 50 animals and is located in the deeper areas of subtropical and tropical oceans. The sea creatures, which are also known as the fake whale, eat like other dolphins, especially on larger fish and head feet.

“The animals stranded again and again.”

Shelley Graham 

Tasmanian sea protection program

Scientifically, the kind of pseudorca crassidens is little researched and sightings are comparatively rare. The International Union for Conservation of Nature classifies the small sword whale as “threatened”. Strandungen, sometimes also mass beaches with several hundred animals, occur, but are less common than with other whale species.

Whales can blur individually or in large groups in the flat water. “Mass beaches are typical of species that live in groups with a matriarch (a› leading animal ‹) and organized by close social bonds,” says the website of the global whale protection organization Whale and Dolphin Conservation (WDC).

The trigger of such disasters can be varied, such as changes in the currents in the sea. According to WDC, extreme events such as an explosion, a chemical accident or diseases could also lead to mass beaches of whales or dolphins. A maritime “shortage of skilled workers” can also play a role. According to the WDC, the lack of experience of individual animals or young lead animals could be stranded. Another danger is underwater noise through military maneuvers, seismic examinations or persistent noises from shipping traffic. These could damage the sensitive hearing of the whales and cause orientation problems.

Scientists worldwide research further potential causes of whale strands. In a joint research project, which is still running until March 2027, examine the Helmholtz Center for Environmental Research, the University of Liège and the Norwegian Polar Institute Possible effects of pollutant loads and underwater noise on the hearing capacity of whales in the Arctic. The project description states: »With melting the ice in the Arctic, new areas for shipping routes, seismic oil expansion, raw material extraction for new technologies (e.g. rare earth) and other anthropogenic activities are accessible. All of these activities can affect whales and dolphins. “

A study by the American scientist Greg silver published in November 2024 in the specialist magazine “Frontier in Marine Science” suggests that toxins from explosive algae flowers could be disoriented and therefore fatal.

Another danger comes from space. One suspects that whales, similar to migratory birds, bats and other animals, have a magnetic sense with which they use the earth’s magnetic field for orientation. If there is disturbances in the magnetic field due to sun wind, whales could take the wrong direction. “This has not yet been proven,” said the WDC experts, “but there are indications of this connection with various beaches.”