David Stemmer’s job as head of the SA Museum’s cetacean collection sometimes has him knee-deep in tonnes of blood and offal to recover rotting carcasses of the largest mammals on earth, but he’s happily turning the ugly into something beautiful for the world to see.
Key points:
- The SA Museum has the nation’s largest collection of cetacea, including 900 dolphin specimens
- Whale specimens are rare because their size makes them difficult to retrieve, process and store
- The collection includes rare pygmy right whales, most of which originate from strandings
The SA Museum has the largest and most comprehensive collection of cetacea in Australia attracting researchers from around the world.
About 38 different species of whales, dolphins and porpoises are stored for research with the bulk of the 1,400 piece collection made up of 900 dolphin specimens.
Mr Stemmer said the collection allowed research on population dynamics to help preserve the marine mammals by identifying and minimising human impact.
But there are logistical considerations and limits on their ability to learn more about the largest cetaceans — some whales are very rarely sighted while others are too remote or bulky to be recovered.
“In general, the large whales are much, much harder to study because of their size,” Mr Stemmer said.
“For some studies, you need lots of individuals to be able to get a good answer — the classic morphological study that is done on smaller animals can’t be done.”
Scientists used the smallest molecules to learn about the largest animals.
“A lot of the studies involve the molecular, looking at genetics,” Mr Stemmer said.
“With the baleen whales, you can sample the baleen plates for isotopes.
“They grow a bit like hair, they’re keratin, and they grow over time so you can sample them along the outer edge and extract the different isotope signatures from where they’ve been through their lives because different areas have different isotope signatures.”
Access dilemma
COVID travel restrictions have impacted research.
“Pre-COVID, we had visitors every now and again studying the collection because one of the other problems with cetaceans is they’re too big to post around the world and the country,” Mr Stemmer said.
The team waited for a baleen whale researcher from the US to be able to travel and assist in dissecting a rare pygmy right whale that came from Port Lincoln.
Mr Stemmer said the fishing industry helped collect and freeze the whale.
“They managed to collect that whole whale for use and put it in one of their bait freezers,” he said.
The pygmy right whale is in its own family and is one of the smallest whales at about 6 metres in length.
“There aren’t many places in the world where they occur and Port Lincoln is a hot spot — most of our pygmy right whale specimens have come from Port Lincoln,” Mr Stemmer said.
He said it was exciting when a stranding was discovered.
“We find out about whale strandings pretty quickly and with smartphones we get photos and we can decide whether to collect it if it’s accessible,” Mr Stemmer said.
“And you have to be able to keep breathing until you don’t notice the smell anymore.
“We actually had to hire a front end loader to move a whale further up the beach so we could collect it and sharks were feeding off it as well.”
At other times, just a sample of the whale would be taken.
“There was a large male sperm whale and we couldn’t collect the whole animal, that was just too much but the local park ranger used a chainsaw to cut the lower jaws off for us.”
Flesh left to rot
Smaller specimens are placed in a 2,500-litre maceration vat with heated water that rots the flesh from the bones — a process that takes several months.
“We also have a large concrete tank, swimming pool size, 35,000 litres, where we put large whales but that tank is not heated so we’re relying on a nice warm summer for the animal to rot away,” he said.
Mr Stemmer enjoyed giving a second life to the whales.
“To go out on a beach and have this dead, stinking blob there, collect it and turn it into a beautiful skeleton for the collection — it gives the sad demise of one of these majestic creatures another purpose.”