Graphic shows how echolocation works and possible theories linked to whales’ strandings.


Nearly 400 whales die in Australia's worst stranding

By Jordi Bou

September 24, 2020 - As nearly 400 pilot whales died in Australia’s largest mass stranding on record, scientists point to a number of potential reasons which could explain the phenomenon, including navigational errors.

While scientists don’t know the exact reason, they do know that whales - and dolphins, which are also prone to mass beaching - are very sociable animals.

They travel in large, close-knit communities which rely on constant communication.

Many of the recorded mass strandings include long-finned or short-finned pilot whales – a species of oceanic dolphin that grows up to 7 metres and can weigh up to 3 tonnes.

Pilot whales use sophisticated sonar to find prey and for orientation, so some theories link strandings to changes in electromagnetic fields.

These changes can be caused by solar storms or earthquakes but there is also a strong connection between active sonar, such as naval sonar, and strandings.

Pilot whales often follow a leader, and are known to gather around injured or distressed whales. one theory is that one leading individual, maybe in poor health, could mistakenly lead the whole group to shore.

Failure of whales’ sonar pulses to detect shoreline in shallow waters could also be a factor.

The largest mass stranding in modern recorded history was 1,000 whales on the shores of the Chatham Islands, a New Zealand territory in the Pacific Ocean in 1918.

PUBLISHED: 24/09/2020; STORY: Graphic News