By BERT GAMBINI
Published May 18, 2023
Eduardo Mercado III, professor of psychology, College of Arts and Sciences, has received a 2023-24 Harvard Radcliffe Institute Fellowship for his “Singers as Sentinels” project that will study how humpback whales can provide warnings of changing ecosystems.
Mercado is among the scientists, writers and journalists in this year’s class of Radcliffe fellows, who will pursue an ambitious project for a full year amid the resources of Harvard University.
The Radcliffe announcement comes only a month after the John Simon Guggenheim Memorial Foundation also named Mercado a fellow for a project that will analyze how humpbacks adjust their songs in response to their surroundings, work that radically contradicts the prevailing hypothesis on the purpose of whale song.
Understanding how whales adapt to changing acoustic and physical environments can help scientists better predict how human actions will affect marine mammals and other species that rely on sound for survival.
Little is known about singing whales’ vocal interactions or what conditions might disrupt such interactions. Conservationists in the 1970s collaborated to help end the slaughter of whales, but the effects of human noise pollution and global warming present a new, equally ominous threat to whales and their ocean environments, according to Mercado.
“It has become increasingly apparent that, for many species, human activities are becoming the major determinant of what animals do,” he says. “Marine species are particularly vulnerable to human activities, in part because the negative impacts on animals living underwater are largely hidden from land lubbers.”
The “Singers as Sentinels” project will combine sophisticated acoustic analyses of humpback whales recorded singing off the coasts of Hawaii and Colombia — geared toward identifying the ways that singers modify their songs in different contexts — with a broader effort to make the general public more aware of the various ways that human noise is increasingly affecting the lives of whales.
Around 90% of world trade depends on container ships that bombard the undersea world with noise that drowns out whale song and releases billions of metric tons of carbon dioxide into the atmosphere.
The project will use a publicly accessible, web-based interface that will provide interested observers with a unique window on the kinds of noise pollution that whales and other marine mammals are exposed to daily.
As part of the project, Mercado will develop a book, “Why Whales Sing and Dolphins Don’t,” that will explain the likely functions of whale songs and why singers may be especially sensitive to noise pollution.
Mercado says this line of research can potentially lift whales to the culturally iconic level achieved in the 1970s with the “Save the Whales” campaign. The “Singers as Sentinels” project will attempt to put a face on the effects of human activities on whales, and oceans more generally, that taps into the symbolism that whales have attained in Western cultures.
“Many today believe that because whaling is no longer a global industry, and because fisheries based on targeting dolphins are now regulated, that marine mammals (as metaphors for nature) are safe,” says Mercado. “In reality, as apex animals within ocean ecosystems, whales are once again poised to be eradicated by human actions.
“This time, the decimation will be unintentional, however, and this time there is much more at stake.”
Beyond its potential for increasing public awareness of the plight faced by marine animals, “Singers as Sentinels” can provide new opportunities for students from underrepresented groups to interface with esteemed researchers from multiple disciplines.
“This project also can shift the emphasis of current whale bioacoustics research away from simply monitoring the movements and density of whale populations, and toward identifying how human activities are forcing whales to adjust their use of sound and habitats,” says Mercado. “I’m immensely grateful to the Radcliffe Institute for giving me the time and resources to make this project a reality.”