When John Dickie spotted a pod of about 15 orcas while captaining his whale-watching boat off Kilcunda on the coast of Gippsland earlier this week, he knew it was a special experience.
"It was just an amazing sight and they were so interactive," he said.
"We sort of pulled up about 100 metres or so away from them … and they just came straight up to us and swum around the boat."
In his 30 years in the industry he said he had seen orcas about three times a year in groups of up to five, but these ones hung around for longer than he is used to and looked different.
"I was a little bit confused about what they were at first because I've seen killer whales quite a few times on different trips, but these guys were a little bit different, a little bit smaller than what we usually see," he said.
It was only later when he sent the pictures to David Donnelly from the Dolphin Research Institute that he realised just how special the sighting was.
"What we've determined is that these are in fact Antarctic Type C killer whales, the first record of them occurring in Bass Strait and in Victorian waters, and only the seventh nationally," Mr Donnelly said.
Mr Donnelly said Type C orcas were the smallest in the world and ate fish, not other mammals.
Two sightings in one day
Mr Dickie's sighting was followed by a second, larger sighting nearby.
"Since that event that happened with Wildlife Coast Cruises, another event was recorded at Cape Patterson, where 30 to 40 Type C killer whales were recorded," Mr Donnelly said.
"When you start talking 30 to 40, that's someone's estimate, we haven't counted them, but it's certainly more than what was seen earlier in the same day and it fits more closely with what we expect Type C killer whales to be in terms of their pod size.
"They typically hang out in groups of anywhere between 20 and over 100 animals at a time.
Why are they here?
Mr Donnelly said the mammals may be moving north so they could shed diatoms – a type of algae that grows on their skin in colder waters.
"If you were to see a Type C killer whale in Antarctic waters, they'd appear a yellowy orange colour, rather than the grey and white colour that we're seeing in the last few days," Mr Donnelly said.
In analysing the pictures from Wildlife Coast Cruises, he also spotted a young calf.
"Every record we have of Type C killer whales in our coastal waters – meaning New South Wales, Tasmania and now Victoria – every record has new calves in it, which is quite amazing," Mr Donnelly said.
"John's sighting the other day is no exception – there was a very young calf in amongst those which we detected in the photography that was supplied to us."
