Scientists say determining age is important in monitoring how they recover from commercial whaling.
ABC Scientists say determining age is important in monitoring how they recover from commercial whaling.

Tasmanian scientists are using a genetic test often employed by forensic experts to estimate the age of humpback whales.

Scientists from the Australian Antarctic Division have worked with others from the United States and the Australian Genome Research Facility to develop the first DNA-based test that can be applied to humpback whale skin samples to determine age.

The mammal’s age is viewed as important in monitoring the recovery of populations after commercial whaling.

The method is based on a test used by forensic experts to estimate ages from corpses, or human blood stains.

“What people have found out recently is that there are some parts of genes that change as you get older, so a chemical modification of the DNA is altered with age,” said AAD molecular biologist Simon Jarman.

“We’ve identified the same genes in whales and found a very similar phenomenon.

“We’re basically looking at chemical changes in just a few whale genes that are really strongly linked to how old they are.”

The humpback whale skin tissue samples are collected with biopsy darts.

The test is accurate to within three years.

“This is the first time that this kind of technology’s been used on wild animals, so it’s got great potential for all sorts of studies in animal ecology,” Dr Jarman said.

“It can tell you things about population size, which is really interesting to biologists studying animals that have a history of exploitation in the past.

“Their population’s obviously smaller than it would have been before the whaling era and we’re very interested to know how many there are now.”

It’s believed the test would be relatively easy to apply to other mammals.

“Adapting it to other whale species should be fairly easy, now that we’ve got a bit of a head-start in having this one for humpbacks.”

Scientists hope they will be able to apply the test to bird species as well.

“We’re very interested in being able to know the ages of penguins and albatross and long-lived birds like that, that have similar population exploitation histories..we need to know about their population health for monitoring what’s going on in the ecosystem.”

Sea Shepherd withdraws

Anti-whaling activists says it is unclear how many whales were killed during the latest Southern Ocean whaling season.

Sea Shepherd Australia is reporting the whaling season is over, with the Japanese processing ship Nisshin Maru on a northerly course back to Japan.

The captain of Sea Shepherd’s Steve Irwin, Sid Chakravarty, says the whaling season was “disastrous” for the Japanese, but he is not sure how many whales were killed.

“Those numbers are put out by the Institute of Cetacean Research, so in a few days while the whaling fleet’s on their way back to Japan those numbers will be put out as a public number and we’ll know how successful this campaign has been,” he said.