Australasian Science: Australia's authority on science since 1938

Caring for Giants of the Deep

By South Australian Museum

The South Australian Museum's marine mammals team will study parts of a minke whale that has washed up at Ceduna on the state's west coast.

Locals spotted the four-metre long whale and contacted the Museum and Environment Department.

Museum zoologist Dr Catherine Kemper says it's the first Minke Whale to wash up on South Australian shores since 1998.

"This will have enormous scientific value. We haven't had a specimen in 14 years and we will be able to determine which species of Minke Whale it is. Our studies help to define whale behaviour and often lead agencies to develop management plans."

A deep cut is present on the whale's skin, however Museum scientists have not been asked to investigate the cause of death in this case. The specimen will be delivered to the Museum on Wednesday 14 November 2012.

This case is typical of the Museum's essential role in collecting and studying important players in marine ecosystems and determining how best to preserve its delicate balance.

Whales and dolphins are close to the heart of many Australians and are symbolic of the amazing life in our oceans. When their carcasses wash up on shore, the South Australian Museum and collaborators make every attempt to study them and report findings to State and Commonwealth governments and other agencies.

The group of scientists, with backgrounds in pathology and zoology, gathers information from live and dead marine mammals to be used in vital research and conservation projects. The Museum has the largest collection of marine mammals in Australia and a long history of research dating back to the 1800s.

Scientists can tell a lot from studying carcasses of a whale species: for example, its growth and age, when it becomes sexually and physically mature, as well as anatomy, population genetics, taxonomy, distribution, cause of death and diseases.

Before 2009 there had been only two specimens of the rare Fin Whale (Balaenoptera physalus) collected in South Australia. In October 2009 when a dead Fin Whale was found washed up on the mudflats near Parham, the Museum's mammal team – led by Dr Kemper – was eager to get to the scene.

"Collecting large whales is hard work but exciting. There is nothing like seeing the real thing to learn about what makes them tick and they are just so big and interesting!" says Dr Kemper.

Before the modern whaling era of the 1900s, there were about 400,000 Fin Whales in the Southern Hemisphere. There are now believed to be less than 10,000 but counting them is very difficult because they live in such expansive oceans. Twentieth century whaling, unlike earlier operations, was very efficient because it used all of the carcass and it could hunt in very remote waters of the Antarctic. The whales are now difficult to study because they are so far away.

"Some people think we can learn all we need to by looking at live animals," says Dr Kemper. "We cannot. The combination of studying live and dead animals is really important in understanding different species and contributing to global conservation practices," says Dr Kemper.

The dissection process is costly and time-consuming. On 2 October 2009, Government staff reported the Fin Whale at Parham to the South Australian Museum. The Museum team wanted to collect the full skeleton and find out why it had died so samples of organs had to be collected. Thus began a $19,000 process to deal with the whale.

"The first thing is to take off the blubber because it is really hard and tough - not like our soft fat," says Dr Kemper. "It's got lots of connective tissue and you have to get it out of the way if you want to get inside to the organs. That takes quite a while."

The team uses flensing knives that are about 50 years old and as big as hockey sticks. After removing the blubber, the flipper and the flukes are cut off. On the second day, they worked to collect vital samples such as reproductive organs and genetics tissues and preserved them.

The skeleton and baleen were then taken back to the Museum's Bolivar facility to be cleaned. The scientists found an infection in the vaginal area however concluded that it would not have been enough to kill this female.

"There was a lot of bruising on the back, so we came to the conclusion that it was likely she was hit by a boat but we can't be absolutely sure of that. Fin Whales, interestingly enough, are hit by large ships from time to time, sometimes getting wrapped around the hull," says Dr Kemper.

"The smell isn't pleasant, but it doesn't worry me," says Dr Kemper. "I'm just so interested in what we are discovering."

The South Australian Museum's work will help organisations and governments protect species so that their essential role in ecosystems can be preserved.