The Portentous Comeback of Humpback Whales
Each July and October, Susan Bengtson Nash packs a crossbow and an air rifle and heads out to sea off the shore of Brisbane in Queensland, Australia. Every time, reliably, humpback whales arrive to meet her. Of all baleen whales, humpbacks are the showiest, breaching frequently and slapping the water with their flukes and wing-like pectoral fins. As they pass by, Bengtson Nash takes aim, pulls the trigger, and a modified dart bounces off a whale’s dorsal flank with a small sample of skin and blubber.
Each biopsy is a treasure trove. It contains information about the whale’s diet, how far it traveled to find food, how much fat it carries, how stressed it is and, if the whale is female, whether it is pregnant. And, by proxy, the information about the whale’s body condition serves as a measure of the health of the Antarctic ecosystem in a changing climate.
The northeast coast of Australia is a humpback whale highway, a corridor in an annual migration between frigid, food-rich Antarctic waters where the whales gorge themselves on krill during the southern-hemisphere summer, and the tropical seas where they mate and give birth in winter.
The big question is whether climate change and other threats will outpace the whales’ recovery.
While en route, with their blubber replenished during the short summer feeding frenzy, humpback whales fast. This makes them a remarkable species to study for Bengtson Nash and her team at Griffith University’s Environmental Futures Research Institute. Within their blubber, humpbacks carry an imprint of the environmental conditions
