When the images of the gigantic bodies rolling over the sandy ground become public, it seems like a leap back in time. As if Tasmania had landed again in September 2020, when around 470 pilot whales stranded in the shallow Macquarie Bay in the west of the island and had to be pushed, pulled and washed back into the sea by experts and activists. Exactly two years have passed since then. The bay is the same, and today’s tragedy is the same as 2020.
About 230 pilot whales are stranded on Macquarie Bay and Ocean Beach this time, with just 35 still alive, according to the Tasmania Parks and Wildlife Service. Why are masses of them stranded again?
“Pilot whales have a strong group cohesion,” explains Helena Herr. She is a marine biologist and researches how marine mammals can be protected at the University of Hamburg. Whales are mostly in so-called schools, i.e. in larger, mostly family groups, explains Herr. The leader of the group is usually an older whale cow, which dictates the direction in which the group swims. “Mass strandings usually occur because the leader deliberately or unconsciously brings the school into shallow waters or bays ,” says the biologist.
Some kind of suicide squad?
There could be various reasons why such a large group of whales has stranded again in Tasmania, an island belonging to Australia . The lead animal may have lost its sense of direction, possibly due to damage to its sensitive hearing from sound waves such as those created during military operations. A kind of suicide squad cannot be ruled out in the animal world either: “The whales follow their leader animal to the death,” Herr explains, and whether it is sick or injured, this can affect the entire group.
Since there have been mass strandings of whales on the Tasmanian coast before, many experts also suspect that the climate phenomena La Niña and El Niño could be a cause of the problem. A change in water temperature creates new currents that push smaller sea creatures into other, unfamiliar areas. The whales follow their prey – and suddenly find themselves in shallow waters.
In Tasmania, the rescue of the surviving whales is now being planned. They are covered with wet towels and rolled on huge tarpaulins. However, there are controversial discussions about the usefulness of such rescue operations. “Like many scientists, I believe that humans should not interfere with wildlife if it is a natural selection process,” explains marine biologist Herr. It is the course of nature that weaker animals are sorted out. “But it’s different when the animals’ problems are man-made – if we caused the suffering, we should also try everything to alleviate it.” Even if the success rate is low.
Due to the strong social instinct of pilot whales, this is not so easy. In 2020, only 111 of the 470 animals survived the mass stranding on the Tasmanian coast. At that time, the helpers noticed that some of the whales that they had to bring into the water with great effort swam back to the shore after being rescued. Lured by the clicking sounds of their fellow species in distress, they returned – and stranded again.