Whale cams reveal ocean giant's feeding habits
Electronic tags with ‘whale cams’ deployed on humpback whales in Antarctica have revealed the secret feeding habits of the ocean giants.
The small camera tags were placed on the backs of humpback whales by Australian and United States scientists working off the Antarctic Peninsula, in the Gerlache Strait.
Australian Antarctic Division whale researcher, Dr Mike Double, said the cameras reveal where and how the mammals are foraging over the summer months.
“The tags show the feeding methods used by the humpbacks in this area of Antarctica, including footage showing the whales lunge feeding into tight swarms of krill,” Dr Double said.
The camera tags are attached by suction cups to the back of the whales for about 24 hours, before they detach and are retrieved by the scientists.
“There’s a camera on the front of the tag and three dimensional motion sensors which record the movement of the whale as well as the time and depth of each dive,” he said.
Lead collaborator on the study, Dr Ari Friedlaender from Oregon State University, said the suite of data collected allows the scientists to reconstruct the underwater feeding behaviour of the whales in great detail.
“The non-lethal research methods allow us to determine how krill abundance affects the feeding success of whales and how any change in krill population due to climate change, commercial fishing, or ocean acidification, may impact the mammals into the future,” Dr Friedlander said.
The researchers also deployed longer-term ‘LIMPET tags’ on the smaller Antarctic minke whales.
Whale research scientist, Dr Elanor Bell, said there is very little information on minke feeding behaviour.
“Minkes are faster and more elusive than humpback whales and often forage in areas with lots of sea ice. This makes it challenging to find and approach them to deploy tracking equipment,” Dr Bell said.
“So it was really exciting to be able to attach some LIMPET tags on this voyage. These will transmit the location and dive depth data to satellites every time they surface for up to two months.”
“This work is part of a long-term ecological research to better understand the divergent impacts of climate change on the ice-dependent minke whales and more open-water humpback whales in this part of the Antarctic,” she said.
The research is being conducted through the International Whaling Commission’s Southern Ocean Research Partnership (IWC-SORP), supported by One Ocean Expeditions and WWF-Australia.
IWC-SORP aims to develop, test and implement non-lethal scientific methods to estimate the abundance and distribution of whales and describe their role in the Antarctic ecosystem.
Whale research video
Australian Antarctic Division whale scientist Dr Elanor Bell
We were studying humpback and minke whales, specifically looking at their foraging ecology, which means where they feed, how they feed, where they're travelling to in order to feed, and looking at their prey as well. We deployed two different types of tag. The first was a video suction cup tag, which has all sorts of really specialist motion sensors inside it as well as a video camera at the front. We were deploying those on the sleepy logging whale at the surface. We'd sort of creep up to them in the boat, we'd slap a tag on their back.
The video records where the whales - where they're going, how deep they're diving, and what they're actually eating. So you see footage of them actually lunging at dense krill swarms in the open water. The limpet tags are different. They are small implantable tags that we were deploying on the minke whales. They stay in the dorsal fin for up to two months, and they transmit the location data and dive data from that whale. And we want to understand what they need, and how these climate changes or these other anthropogenic changes might impact the whales in the future.