Following Antarctic whales for climate change clues

The calf is even more curious, raising its head out of the water. The young marine mammal seems to examine us; we’re a strange group of tiny, terrestrial mammals in a small, rubber boat. I can’t stop myself greeting the calf: “Hello, beautiful.”

Baby humpbacks spend a year nursing on their mothers’ rich milk. With a hungry, one-tonne newborn, calories are important.

“We need to find the most critical feeding habitats for whales, so we can protect them,” explains Chris.

The health of whales, he explains, shines a light on the health of the whole Antarctic ecosystem. And whales are physically necessary for a healthy ocean: Humpbacks eat krill, and krill eat microscopic plants that live in sea ice – plants that absorb planet-warming carbon as they grow. Whales then poop (in vast quantities) and fertilise the marine plants.

It’s a virtuous, productive cycle that climate change is disrupting. “These are natural processes we rely on for fresh air, food and clean water,” says Chris. “Places like this are important for all of us.”