MORE than 150 short-finned pilot whales stranded themselves on the southwestern tip of Australia, stunning parks officials and prompting a massive rescue effort to save as many as possible.

The mass beaching likely took place sometime Wednesday night to early Thursday morning at Hamelin Bay in Western Australia, according to the state’s parks and wildlife service. Videos of the scene showed dozens of the animals piled against each other on the shore, many with their tails still wiggling, as onlookers expressed concern. Some whales were fully on dry land, while others were in shallow waters.

Officials quickly shut the beach down, issued a shark alert for the area and rushed equipment and trained volunteers to the site to try to return the pilot whales to deeper water. Despite rescue efforts, only five of the stranded whales survived the ordeal.

The surviving whales, up to 5.5 meters long, were moved to deeper waters, but Parks and Wildlife Service Incident Controller Jeremy Chick warned Saturday that whales often return to dry land after mass stranding events.

He asked the public at Hamelin Bay, south of Perth, to keep an eye in case they spot a stranded whale.

A sixth whale was freed into shallow waters Friday but it beached again and had to be euthanized.

Authorities were continuing to sweep the surrounding beaches by air and sea Saturday, although the sheer number of dead whales in the water, rocky terrain and rough seas were hampering efforts.

There are numerous theories for why mass beachings happen – though the phenomenon has taken place for centuries, as documented by age-old engravings and paintings. Whales and dolphins are both cetaceans. They are social animals that travel in close-knit pods, and some scientists believe they can become stranded en masse if the dominant member leads the group too close to shore while chasing prey or becoming disoriented, according to Live Science.

Environmental groups have also argued that sonar – used to map the ocean floor or for military purposes – can trigger mass strandings in dolphins and whales, who can be sensitive to underwater noises.

The Western Australia parks service noted that short-finned pilot whales are particularly susceptible to getting stranded, citing two previous mass beachings that took place nearby in 1984 and 1991.

(SD-Agencies)