Humpback Harmony

Researcher questions health of Alaska’s most visible whales

BY EMILY MOUNT


A fiery sunset fades into the sea as we crowd against our ship’s railings, eager to witness one of southeast Alaska’s largest inhabitants: the humpback whale.

A rush of air that sounds like a throaty trumpet explodes beside the ship, complete with fishysmelling vapor. Passengers cheer, snapping photos as a black back slides through the water followed by 15-foot flukes. Dr. Andy Szabo, director of the Alaska Whale Foundation, points out the unique pattern on the underside of the tail. Whales have been his passion since childhood, and today he is on the cutting edge of southeast Alaska humpback research, from scrutinizing population health to investigating whale culture.

Alaska’s humpbacks have not always been admired by tourists and studied by scientists. Nineteenth and twentieth century whalers hunted humpbacks for their blubber, which was rendered into oil for the burgeoning needs of the Industrial Revolution. Baleen was also prized for its strong, flexible uses, including corsets stays, skirt hoops, and buggy whips. By the time a moratorium ended humpback whaling in the 1970s, the North Pacific population hovered around 1,200 individuals.

Today that population has rebounded to about 20,000 humpbacks, with 4,000 summering in southeast Alaska. These whales gorge on a rich seafood buffet, occasionally using a unique foraging strategy Szabo studies: bubble-net feeding. Bubble-netting is an elaborate, highly orchestrated behavior first described by whalers in the 1920s.

Humpback whales bubble-net feed, an orchestrated effort that rounds up prey into an easily captured mass.

Several whales dive below a school of fish, each with specific duties. One whale blows a circle of bubbles to corral the fish, while others flash the white undersides of their pectoral fins to frighten their prey into a panicked mass. At the key moment, another whale emits a piercing call and the whales simultaneously swim into the fish, maws gaping, and erupt at the surface in a spectacular display.

“Bubble-netting is a very complex suite of behaviors,” Szabo states. “They’re using an ephemeral tool in a 3-D environment to capture prey that’s highly evasive.” He is studying whether whales adjust the size, quality, and volume of the bubbles and make adjustments based on the type of prey and number of whales feeding. About 60 to 80 Southeast humpbacks are known to bubble-net, rendezvousing and remembering their specific roles each summer.

This cooperative behavior is a clear display of humpback intelligence. Researchers document other indicators of high intelligence, including abundant spindle neurons and observations of compassion and empathy, all characteristics of creatures like elephants and primates.

“These whales have all the things necessary for living in complex social structures and societies,” Szabo notes, going on to explain that these social networks create a unique whale culture, where learned behaviors are transmitted and stored within the population.

In spite of coordinated and refined feeding tactics, Southeast’s humpback population is going hungry. A whale consumes about 500 pounds of food daily, and it seems there is not enough to go around. Szabo is noticing increasing numbers of whales overwintering in Alaska, presumably to feed year-round, instead of swimming to their Hawaiian breeding grounds where they would fast through the winter. There are more skinny whales and fewer calves. Szabo worries that humpbacks, which were removed from the Endangered Species List in 2016, were a success story celebrated too soon. Has the humpback population reached its carrying capacity or is it facing new challenges?

A group of humpback whales spouts at sunrise.

These are questions Szabo seeks to answer by examining the health of Southeast’s whales. He deploys drones equipped with cameras, laser range finders, and collection containers to gather previously inaccessible data. With these drones, Szabo can measure a whale’s length and girth, information needed to calculate volume and body mass and estimate age. This summer, he plans to fly a drone into whale blow, the cloud exhaled when the whale comes to the surface to breathe, and collect a sample of whale snot. This material can be used for hormonal assays and genetic testing. Szabo also collects skin samples to reconstruct a whale’s diet and conduct isotope analysis. In 20 minutes, he can conduct a complete health assessment.

Szabo’s drone footage shows that half of the whales bare scars of entanglement in fishing gear. Since 1997, the Alaska Whale Foundation has participated in the Regional Stranding Network to assist whales caught in fishing gear and to train first responders in entanglement procedures. While the future of Alaska’s humpbacks is a question mark, Szabo’s research is putting the pieces together. On the bow of our ship, under a twilit sky, he gathers excited passengers to discuss humpback culture, research, and conservation.

“People get very excited about whales having a rich culture, being tool users, being so intelligent,” he tells me later. “It inspires them to want to protect these animals. And from there it’s a natural extension to want to protect the oceans and start thinking about our role in conservation and what we can do. We need more of that in this world.”


Emily Mount is a naturalist, writer, and photographer. emilymountphotography.com