Humpback whales revel in Alaska's cruise-free summer

It’s been a quiet summer in the waters of Alaska.

With zero cruise ships carrying whale-watchers and glacier gazers—a situation which temporarily boosts the state’s population of 730,000 by 1.4m individuals—the humpback whales in the vicinity have grown much more talkative.

This is the impression that delighted researchers are getting.

According to Dr Michelle Fournet, director of the Sound Science Research Collective and research fellow at Cornell University, “It’s the first time in human history that we’ve had the technological ability to listen to these whales in a meaningful way without us interfering … it’s a really, really big deal.”

She has been listening in on whale conversations for a decade, and said that the last time researchers were able to listen in on humpback conversations in a quiet ocean was in 1976. At that time, commercial whale watching had began, and their population were smaller as humpback whaling had only been banned a decade ago. Since then, their population has grown.

On normal pre-pandemic days, there can be as many as 65 whale-watching boats in Juneau and Glacier Bay national park. A busy day can see 10 or more such vessels clustered around a single whale or group. This has caused the humpbacks to change their behaviour by calling louder and calling less.

“When an animal calls less, the likelihood of it finding a comrade goes down significantly,” said Fournet. “So, we alter their social structure.”

In addition, researchers have been gathering blubber biopsies to analyse the whales’ cortisol levels and will compare them with those obtained in 2014. While it is still too early to come to any conclusions, Dr Heidi Pearson, associate professor of marine biology at University of Alaska Southeast, said that “based on my observations, it does seem that whales are exhibiting more resting behavior this year … I have also observed larger groups and more social behavior than I have in previous years.”

Conducting these studies aims to establish a meaningful behavioral baseline and a better understanding of how tour vessels impact marine creatures.

“We’re not going to eliminate cruise ships, nor should we,” said Fournet, “They’re really important economically and for people to interact with their environment … but what I hope is that as we start to ramp the noise back in we can identify the tipping point.”