Question: Why Do So Many Whales Breach And Die On Australian Beaches?

Answer: Nobody really seems to know. But there are a few theories.

A rescuer in Australia tries to keep a live whale hydrated. (Tony Ashby / AFP/Getty Images)

Recently, 80 long-finned pilot whales breached themselves in Hamelin Bay, south of Perth, and all but 11 died. Since November, over 500 sperm whales and pilot whales have breached on Australian coastline, and over 400 have died.

The LA Times blog goes on to quote some scientists’ theories from an AP report.

Scientists have offered some theories: The whales may be chased by predators such as killer whales, or they could be following prey themselves. The sonar they use to navigate the dark seas could be hindered by natural geomagnetic factors such as iron ore deposits. They may swim into an area where sandbars or peninsulas block their exit. Or they may follow one ill or injured pod member and refuse to leave it.

Human activity such as undersea exploration for petroleum or the sonar of submarines also can interfere with whale and dolphin navigation.

Marine researcher Karen Evans said the timing is right for an increase in beachings. In 2004 she co-authored a study concluding that beachings peak in a 10-year cycle linked to climate changes in the oceans.

“We’re in a peak period now,” said Evans, of Australia’s Commonwealth Scientific and Industrial Research Organization. “What happens in that period is the climate factors increase the prey field near the shore, forcing whales closer to shore and thereby increasing the probability that they will strand.”