Significant advances in non-lethal research on Antarctic minke whales
Satellite tags have been deployed on Antarctic minke whales, giving researchers access to more comprehensive information about them than ever before.
Australian and US scientists aboard a US-led voyage to the West Antarctic Peninsula in February this year deployed a range of different tags on 15 Antarctic minke whales, allowing a greater understanding of their behaviour.
Three additional minke whales were tagged earlier in the summer in the Ross Sea region of Antarctica by US researchers.
Environment Minister Tony Burke said that the work was carried out from the US National Science Foundation research vessel, Point Sur, as a part of the US Antarctic program. The research contributes directly to the Australian-led, Southern Ocean Research Partnership which is endorsed by the International Whaling Commission.
“This is a great step forward in our understanding of Antarctic minke whales and confirms yet again that we don’t need to kill them to study them,” Mr Burke said.
Australian Antarctic Division Chief Scientist Dr Nick Gales, who was on the voyage and deployed most of the tags, said it was hoped the animals would be tracked over the next few months.
“The data from the tags deployed on this voyage will be the first to measure the movement patterns of Antarctic minke whales on their feeding grounds, and it is hoped that they will indicate where these animals go to breed during the winter months,” Dr Gales said.
Also during the voyage, Dr Ari Friedlaender and US colleagues deployed a number of short-term tags which have already provided information on the depth at which Antarctic minke whales are feeding and the manner in which they catch their prey, Antarctic krill.
Prior to this summer the movements and diving behaviour of these whales was something of a mystery as no tags had been deployed on the species.
Mr Burke said that the non-lethal research conducted by US and Australian scientists had, in a period of months, provided significant results in relation to Antarctic minke whale feeding and movement behaviour in stark contrast to the decades of lethal whaling by Japan.
Results from the voyage will be reported to the International Whaling Commission’s Scientific Committee in Korea in June.
Antarctic minke whale tagging
Australian Antarctic Division Chief Scientist – Dr Nick Gales
This was a combined voyage with the United States Antarctic Program and its actually focusing on both humpbacks and minke whales. The idea is to work in a place in Antarctica where both animals are feeding and have a look at how they feed differently.
Went down to a place called the Gerlache Strait, which is a beautifully protected stretch of water in among the islands off the western side of the Antarctic Peninsula and worked in the Bays there. It’s really productive, it’s an area where a lot of Antarctic krill move through the whole area. Sort of size of prey/patches at different depth and we have no idea what those are. So this was actually for minke whales, our first real insight into the differences between these two key species.
So we are using a whole range of different tags that are giving us different information and at the same time we have tags on we have boats going round looking at the prey, the depths at it and what’s in their environment.
So we go from the very short term tags, and we have to get these ones back, so you put a tag on the back of an animal, it’s held on by suction cups and it will stay on there for hours to perhaps one day. And then it will just fall off naturally, the suction cups will give up and it will float to the surface and we will retrieve it. And it measures everything. So we can tell the number of tail fluke strokes on the way down to the prey, pitch and role and turning through the prey and everything, so we get incredibly dense information and at the same time we measure with echo sounds from a separate boat where the krill are.
And then another type that we stick on the animal that have to stay longer. So these are fired through the skin of the animal and then they just embed in the blubber and the underlying tissue just below the blubber and they stay on, well we hope, for months. They just give us location, but they give us the middle to large scale movements of the whales. So where they go from those summer feeding grounds, how they move around those summer feeding grounds and we hope they last long enough to tell us where they go for their winter breeding.
We had no idea how minke whales were going to act around the small boat. They are a much smaller whale than the type of whales that we have a lot of experience in tagging and they are much faster. So the boat driver sits alongside a group of minke whales and slowly comes in on the boat until we are just part of a school of whales and then they are surfacing around us. Then it’s a matter of me on the bow, selecting a whale and then when that animal surfaces in the right range and the right distance from the boat shooting a tag onto the back of that whale. So it’s quite tense, but it’s really exciting when we successfully deploy the tags.
This summer is the very first time ever that these type of tags have been put on Antarctic minke whales, in fact any type of tag. So it’s really exciting we are going to combine the data and really bring forward brand new information about this species.