Each year hundreds of orcas mass at a hotspot off Western Australia’s south coast, and one expert thinks the whales are among the healthiest in the world.
Key points:
- WA’s south coast whale watching season is underway with large numbers already recorded
- The Bremer Canyon has gained International interest for its abundance of orcas and other marine life
- There is plenty of prey in the water and an American whale expert says the orcas are well-fed and fat
Pods of more than 70 killer whales have been recorded at the Bremer Canyon, a marine play and hunting ground, about 70 kilometres off the coastal hamlet of Bremer Bay.
The annual orca season has started with large numbers already recorded, attracting scientists and tourists from across the globe.
Among them is American marine naturalist and Orca Behavior Institute member Sara Shimazu.
Ms Shimazu has studied orca around the San Juan Islands, a North American hotspot near the border of the United States and Canada, and is now comparing the animals to their WA counterparts.
“They [WA orcas] look extremely healthy, really, really healthy whales, very hefty, large animals,” she said.
“They have a lot of food, and they’re socialising, so they’re going to be in a healthy weight for having a lot of babies and those babies are going to be surviving and thriving”.
The Bremer Canyon has gained international interest for its abundance of orcas and other marine life, and is considered among the best places on earth to watch the apex predator in action.
Ms Shimazu said the killer whales in Bremer Bay, which is about 500km south east of Perth, are the healthiest population of the creatures found anywhere on the globe.
“This is based on their fat content. They’re fat and have fat rolls,” she said.
“In 10 years, we’ve probably had close to 20 newborn calves.
“For them to reproduce and birth and bring them up in this region, is absolutely everything that the species needs to do to survive”.
‘Explosion of birds and blood in water’
Naturaliste Charters Whale Watching Owner Paul Cross has seen enormous numbers of kiler whales since the season started in December.
“We had an estimated 30 killer whales predating on other animals, potentially beaked whales, and it went for a series of about two hours in several different locations, surging up and down the edge of the continental shelf, and took out about three individual whales,” he said.
“An explosion of birds and blood in the water.”
The abundance of orcas has prompted an early start to the tour season in December for the first time.
“Traditionally, the second of January is when we start, but now we actually don’t know when the season does start for these killer whales,” Mr Cross said.
Orcas are clever animals and have been documented working as a group for shared benefits.
“They’re the wolves of the ocean,” Mr Cross said.
“They’re very, very sophisticated animals and they do kind of share the food amongst several different family groups and hunt as one unit when needed.”
Why do orcas mass at the canyon?
The area has been the scene of some historic scientific firsts, including the first documented predation of a rare Cuvier’s beaked whale in 2018.
The knowledge of the existence of the orcas in the area is relatively new, with scientists only becoming aware of their migration through the “hotspot” just over a decade ago.
The reason the species congregate at the site is still not entirely understood and research continues.
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