Conservation scientists are studying the health of Antarctic whales using a custom-made crossbow.

The researchers use the device to take remote biopsies from wild humpback whales in order to study the health of the animals.

It’s an effort that is revealing how the food supply of Antarctic whales could be affected by climate change. With sea ice declining at an alarming rate in this fragile environment, the whales’ giant bodies hold clues about the effect that’s having on the whole marine ecosystem.

BBC science correspondent Victoria Gill joined a whale research mission, led by the wildlife charity WWF, in the Antarctic Peninsula.

Filmed by Phill Edwards. Produced by Kate Stephens. Edited by Victoria Gill