UH Hilo’s Marine Mammal Lab contributes to milestone humpback whale study
In the study, working with 60 collaborators, UH Hilo biologist Adam Pack’s Marine Mammal Laboratory contributed over 10,000 tail fluke images from Hawaiʻi and Alaska from its archival catalog of over 30,000 images.
By Susan Enright.
In one of the largest collaborations among humpback whale researchers, 60 co-authors contributed to the just-published paper, “Bellwethers of change: population modelling of North Pacific humpback whales from 2002 through 2021 reveals shift from recovery to climate response,” in the scientific journal Royal Society Open Science.
“It shows how when we all pool our resources and talent together we can learn remarkable things about humpback whales and their marine environment,” says Adam Pack, who holds a joint appointment in the departments of psychology and biology at the University of Hawaiʻi at Hilo. For this study, Pack’s lab contributed over 10,000 tail fluke images from Hawaiʻi and Alaska from its archival catalog of over 30,000 images.
The study was led by Ted Cheeseman, developer of Happy Whale, an online automated humpback whale tail fluke matching program and database.
“The paper pooled together tens of thousands of humpback whale tail fluke photograph from scores of research groups including UH Hilo’s Marine Mammal Lab,” says Pack, noting that “the underside of a humpback whale’s tail fluke has a unique pigmentation pattern and trailing edge that can serve as the ‘finger-print’ for identifying individuals.” Pack’s nonprofit, The Dolphin Institute, also contributed data for the paper.
The results showed that the population of humpback whales in the North Pacific increased to a peak estimate of 33,488 +/-4,455 whales in 2012. However, a 20 percent decline in abundance through 2021 suggests that the population reached carrying capacity due to loss of prey resources.
This was especially reflected in the Hawaiian humpback whale breeding and calving area for North Pacific humpbacks, in which abundance had decreased by 34 percent by 2021 from its peak in 2013.
In contrast, no parallel decline was observed over this period in mainland Mexico, a smaller breeding ground for North Pacific humpbacks.
Sandwiched within these years from 2014 to 2016, an unprecedented in size marine heatwave adversely impacted marine resources, which humpback whales and other species rely on for sustenance. The result appeared to be several years of poor reproductive and physical health for many humpbacks wintering in Hawaiʻi and summering in Alaska.
Related stories
Collaborative humpback whale study continues in Hawaiian waters
Acoustic study documents humpback whales move daytime singing offshore
Story by Susan Enright, a public information specialist for the Office of the Chancellor and editor of UH Hilo Stories. She received her bachelor of arts in English and certificate in women’s studies from UH Hilo.
