Humpback whale health study could prompt new whale watching regulations in Juneau
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Pregnant and nursing humpback whales rely on the protected waters near Juneau to fatten up on herring and krill while raising their young. But calves were involved in nine of the 14 recorded incidents of whales getting entangled or hit by boats in the past four years.
These are the key preliminary results from a study of Juneau’s whale health that started in 2020 in response to rising concerns about whether the multimillion-dollar whale watching industry might be harming the humpbacks that spend the summer here. The City and Borough of Juneau used cruise ship passenger fees to support the research with a $160,000 grant. The forthcoming final results could drive the city to consider limiting the number of whale watching boats.
Heidi Pearson, a marine biology professor at the University of Alaska Southeast, leads the Juneau Whale HEALTH Project. She said the team’s initial results should lead to greater conservation efforts, since whale mothers drive population growth.
“The fact that we’re finding that females stay here longer, oftentimes with their calves, means that we should probably think about some additional precautions to protect this really precious component of the population,” she said.
Tourists in Juneau spent $60 million on whale watching in 2019, the latest year with available data. There are more than 80 whale watching boats currently operating in town, according to NOAA.
It’s illegal for vessels to get within 100 yards of humpback whales, speed near them, block their path or disrupt their behavior. There are also voluntary federal and city guidelines that some whale-watching companies follow to ease human impacts, such as not idling near the whales and limiting observation to 30 minutes.
But Alexandra Pierce, the city’s tourism director, said that isn’t enough to protect whales from the attention.
“We’re the biggest whale watch destination in the world,” Pierce said. “We don’t know of any destination with more vessels on the water. It’s a numbers problem, even if individual operators are behaving well, and a lot of them are.”
In 2023, a whale calf named Tango was killed by a vessel. While officials could not identify what kind of boat struck the calf, they said that collisions are fairly common.
Pierce said she is working with the industry to try to come up with a plan to regulate the number of boats on the water. Right now, there’s no limit.
Meanwhile, the research team is still working through the data. Their final results will include whale stress levels, comparing the early COVID-19 pandemic years when there was less boat traffic to the last couple of years when tourism picked up again. To do this, they measured the stress hormone, cortisol, in samples of blubber taken from live whales.
A peer-reviewed scientific paper is coming later this year or next. It should give researchers and regulators a greater understanding of how humpback whale health is affected by humans watching them.
Whale acoustic data courtesy of Michelle Fournet, collected under NMFS ESA/MMPA Permit No. 20648.