2009-01-23

Sperm Whales Strand Off The Coast Of Tasmania, Australia

48 sperm whales, or cachelots, have stranded off the coast of Tasmania, Australia. Only five of those that have stranded are though to have survived. Local authorities are working to refloat the surviving animals.

Whales strand for many reasons and this particular area seems to be notorious for such events. Deep sea whales that are also highly sociable, such as sperm whales, are particularly vulnerable to mass live strandings like this.

Mark Simmonds, WDCS Director of Science comments: ‘This is a tragedy and one of the largest strandings of sperm whales known from Australia.

Whales may become confused in shallow waters, especially where there are certain features like sand bars sticking out into the sea. Once in trouble, they tend to stay with each other, trying to help and comfort each other but ultimately this leads to whole groups coming ashore. In other situations, this same tight group cohesion helps to protect them; for example they co-operate for feeding, defence and care of their young.”

Scientists in Australia are linking this particular event to unusual wind conditions that have caused an upwelling of nutrients in the area. This in turn has brought the sperm whales’s prey, mainly schooling squid, close to shore, and the whales have followed. Because of their huge size, once stranded, it is virtually impossible to return a sperm whale to the sea. Heavy duty lifting equipment is usually required to move them and in many locations it may be impossible to get to the site. There is also the problem that even if returned to the sea, the whales may strand again or may have been so badly wounded by the stranding event that they cannot survive. Once stranded, heavy whales very rapidly become damaged by the pressure of their own body weight on their internal organs.

Sources: Australian Press – including: The Sydney Morning Herald