This marine biologist discovered a unique blue whale population in Sri Lanka

Pooping whales changed the course of Asha de Vos’ career.

The Sri Lankan marine biologist was aboard a research vessel near her home island in 2003 when she spotted six blue whales congregating. A bright red plume of whale waste was spreading across the water’s surface.

De Vos, then a master’s student, recalls being “super excited.” What she witnessed went against prevailing dogma: Her textbooks and professors had taught that blue whales, like other large whales, embark on long-distance migrations between colder feeding areas and warmer breeding and calving areas. But seeing whales pooping in tropical waters meant the behemoths must be feasting locally.

Intrigued, de Vos spent the next few years documenting how blue whales near Sri Lanka differ from those elsewhere in the world. For one, the population feeds on shrimp rather than krill. The whales also have unique songs. But the key difference, she realized, is that they remain year-round in the waters between Sri Lanka, Oman and the Maldives — making them the only nonmigratory blue whales in the world. Abundant upwellings of nutrient-rich water from the ocean depths support a steady food supply for the whales.

Eventually, the International Whaling Commission, the intergovernmental body dedicated to protecting whales, recognized Sri Lanka’s blue whales as a distinct subspecies called Balaenoptera musculus indica.

This distinction is crucial for conservation management, explains retired whale biologist Phillip Clapham, formerly of the U.S. National Oceanic and Atmospheric Administration’s National Marine Fisheries Service. Small, localized populations — like the one in Sri Lanka — face higher risks of being wiped out in the face of environmental or human threats, such as deep-sea mining.

More than two decades on, de Vos is now one of Sri Lanka’s most renowned scientists — famed for nurturing the country’s nascent marine biology scene. She is also an ardent champion for greater diversity among researchers in ocean conservation.

De Vos has garnered numerous accolades, including being named a National Geographic Explorer, a TED Senior Fellow and one of the BBC’s 100 most inspiring and influential women of 2018. But such recognitions don’t spur her on.

“I’m driven by trying to make a change,” especially around the negative narrative many Sri Lankans hold for the ocean, she says. “I want people to fall in love with the ocean … to recognize the ocean as this incredible space that is life-giving in so many ways.”

Setting her own course

For all her love of the deep, de Vos’ early memories of the ocean — a mere mile from where she grew up in Sri Lanka’s capital, Colombo — are, surprisingly, tinged with fear. Like her compatriots, she was raised with repeated warnings that the ocean was “a big beast” to avoid, unless you were fisher­folk with little choice but to venture into such unforgiving territory.

“There were often stories of drownings that came with people who went to sea,” she says. Most people in Sri Lanka never learn how to swim, despite living on an isle so picturesque it’s often called the “pearl of the Indian Ocean.”

“People have this disconnect with the sea” de Vos says. “Life always ended at the shoreline.”

The few people who do learn how to swim usually stick to swimming pools. The ocean is “not recreational space,” de Vos says. “I’d say it’s a common problem, particularly in poorer nations where you don’t have time to waste and there’s no frolicking on the beach.” But her forward-thinking mother sent her for swim classes. The young girl took to the water so well that she soon began competing in freestyle sprint events.

Her love for the ocean, however, stemmed from another source: secondhand National Geographic magazines her father would bring home from the local bookshop. “It was just the pictures that really drew me in,” de Vos says.

By the time she turned 17, de Vos had narrowed her career path to marine biology. No local universities offered such a course, and she hadn’t heard of anyone from Sri Lanka who had ever ventured abroad to pursue the subject, but that didn’t deter de Vos. Nor did just missing the required grades for her dream school, the University of St. Andrews in Scotland, which has a strong marine biology program. “I called [the university] and said, ‘Look, I really want to come to your school. I know I’m capable,’ ” she recalls with a laugh.

Her powers of persuasion worked, kick-starting an academic journey that would take her through three continents — including a Ph.D. in Australia and a postdoc in the United States that she completed in 2015.

The journey hasn’t always been smooth sailing. The naysaying began when she applied for university. “There’s no scope in this country for a marine biologist,” people would say. “They couldn’t understand that there could be work, there could be jobs out at sea,” de Vos says. “I always joke now that maybe people thought I was going to go to university and then become a fisherwoman.”

As de Vos progressed in her career, the criticism continued, both from within and outside her country. In a personal essay she penned for the New York Times, de Vos recounts a handful of fellow scientists from wealthier nations who questioned her authority as a researcher from an impoverished country, assuming that she would “lack the knowledge, know-how and interest to participate in marine conservation.”

Meanwhile, fellow Sri Lankans criticized de Vos for not staying within the boundaries of a “respectable” woman, engaging in relatively risky, labor-intensive outdoor tasks. A fisherman piloting a boat she was on demanded to know what her husband thought of her being out on the water and “getting black in the sun.” De Vos replied that she wasn’t married. The man retorted, “I thought as much.”

Such critics served only as fire starters. “I was like, ‘OK, whatever. I’ll show you,’ ” she says. “In many ways, I’m grateful for the challenges — they really made me who I am. They made me have to think outside the box. They made me have to work superhard and really grind at what I do.”

For Clapham, who was one of her Ph.D. examiners, it is this steely, determined de Vos he knows and loves. “She’s just a force of nature” and is simply relentless, he says.

Creating a lasting legacy

Today, de Vos continues to study cetaceans through the Sri Lankan Blue Whale Project, which she launched in 2008. “We have the longest running dataset of blue whales in this part of the world,” she says, including a photo catalog of hundreds of individuals in the population.

But much about the creatures remains unknown, including their precise numbers and what drives long-term fluctuations in their abundance. During the project’s first five years, de Vos and her team observed numerous sightings of the giants, sometimes between 10 and 12 creatures at a go “just blowing everywhere,” she recalls. “But now on the southern coast, we don’t see as many blue whales.” She and her team are trying to figure out why and whether it’s cause for concern.

But the researchers are limited by their vessels, which can only support day trips rather than longer journeys farther out to sea. “We are searching such a tiny sliver of ocean,” de Vos says.

In addition to the whales, de Vos also surveys the biodiversity of their deep-sea environment. She conducted, as far as she knows, the first such audit of the northern Indian Ocean in 2022. “I do these things from a conservation perspective.… People are getting more and more bold about what can be done in these deep-sea environments,” she says, citing underwater mining as a potential threat. “I work with whales and that’s my primary love. But the whales need a perfectly healthy ecosystem because they don’t just live in a bubble where everything around them doesn’t bother them.”

A key aim of de Vos’ work is to protect blue whales from ship strikes. Sri Lanka lies along one of the world’s busiest shipping routes, and in a survey of 14 stranded whales that had died from ship strikes in 2010–2014, a total of nine, or more than 60 percent, were blue whales.

De Vos brought the danger of shipping to light in 2012. It “started a whole cycle of conversations” with the Sri Lankan government, International Whaling Commission, World Shipping Council and other bodies. These talks culminated in victory in 2022, when the world’s largest container shipping firm, the Mediterranean Shipping Company, announced it would reduce the speed of its ships when traveling around the island and adopt a more southerly route that avoided the whales.

Another aim is to get more Sri Lankans to appreciate the ocean and the importance of protecting it. “My whole goal is to create love for the ocean and remove the fear,” says de Vos, who wants to inspire custodians, or “ocean heroes.” To this end, she gives her time to numerous outreach events, including public talks and monthly science journal clubs. In 2017, she founded the nonprofit Oceanswell, Sri Lanka’s first marine conservation research and education organization. “For me,” she says, “the education component is as important as the research component.”

“She’s a tremendously engaging and eloquent speaker,” Clapham says. “She’s a lot of fun when she’s doing educational stuff.” He recalls how de Vos once created animation to explain what blue whales typically eat, snubbing more traditional presentation formats. “It was very entertaining,” he says.

To help grow Sri Lanka’s nascent marine biology scene, de Vos advises universities on how to teach the subject.

Lasuni Gule Godage is among the first students to pursue a master’s degree in marine science and fisheries at the Ocean University of Sri Lanka, created in 2014 by the Sri Lankan government to promote oceanic education. De Vos was instrumental in establishing and obtaining funding for the university’s pioneering program.

De Vos is also a mentor. Gule Godage notes how de Vos advised her on how to conduct fieldwork. “I faced many challenges because there was no postgraduate program [at my school],” Gule Godage says. “But Dr. Asha supported me so much.”

De Vos doesn’t want others to go through what she did. “My goal is to give away everything, whether it’s my knowledge or tips on how to do something better,” she says. “I always tell people when I die, I don’t want everything [I’ve done] to end.”