You’d be surprised what you can learn from a whale’s blowhole.

Scientists have been trying to gather useful data from whale exhalations, or whale blow, for nearly a decade. The liquids in whale blow carry important information about a whale’s reproductive maturity, pregnancy status, metabolism, and stress levels.

We have ways of gathering whale blow, motoring next to surfacing whales, sampling their blow with a long pole and backing off again before the animal is disturbed. Some researchers have even had success outfitting drones with petri dishes in order to collect samples. (Watch: “Scientists Fly A Drone To Collect Whale Snot”)

Scientists Fly a Drone to Collect Whale Snot

But even once gathered, whale blow, and its usefulness in research, is often compromised—by seawater.

Because whales blow at the surface of the ocean, water gets mixed in with the material they expel. This dilutes the samples, like a breathalyzer that can detect the presence of alcohol, but not the concentration.

Fortunately, there is now a way to distill the important material from whale blow, according to a new study in Scientific Reports. By measuring a substance known as urea, a naturally occurring byproduct of metabolism found in blood, urine, and exhalations, researchers are now able to determine exactly how diluted the blow sample is.

In this way, urea is sort of like a decoder ring that allows scientists to record accurate values for hormones and other important biomarkers.

“This tool is really going to have the potential to broaden our perspective,” says Elizabeth Burgess, an associate scientist at the Anderson Cabot Center for Ocean Life at the New England Aquarium and lead author of the study describing the technique.

The Right Whales for the Job

According to Burgess, she and her coauthors would not have discovered the importance of urea if not for North Atlantic right whales (Eubalena glacialis).

Despite the fact that there are fewer than 450 of these endangered giants left, North Atlantic right whales are one of the most studied whale species on earth. Scientists keep a detailed roster of every whale in the population, including details such as sex, age, genetics, and reproductive history.

The team used information they already had about North Atlantic right whales to sample the hormone levels found in whale blow and match them against samples taken with other methods, such as fecal and blood samples.

“We were drawing on over 40 years of data collection by the North Atlantic Right Whale Consortium, which is catalogued by the New England Aquarium,” says Burgess. (Read: “This Is What Whale Breath Smells Like”)

Diane Gendron, a marine biologist at Mexico’s National Polytechnic Institute and a pioneer in the field of whale blow research, called the new study “very important for long-term monitoring,” since it’s much easier to get blow samples than it is to rely on feces.

After all, you never know when a whale is going to go.

Analyzing urea will help scientists understand more about the whales’ physiology, including the way the animals respond to stressors like noise pollution and entanglements with fishing gear—currently the number-one killer of North Atlantic right whales.

For North Atlantic right whales, the scientific breakthrough couldn’t come too soon. It’s been nearly two years since researchers have spotted a new calf in the population, and some experts worry the species could die out in as little as 20 years.

Wonderful World of Whale Snot

While North Atlantic right whales are the most threatened, they are far from the only animals with blowholes that could benefit from a better breathalyzer.

At the University of Manitoba, master’s student Justine Hudson spends her field days attempting to sample beluga snot to measure stress levels across the population.

“This paper will definitely help my research,” says Hudson. “Our samples contain a lot of water because we're collecting them from free-swimming belugas, which makes it hard to quantify the amount of respiratory vapor in the sample.”

As with the right whales, finding ways to study belugas without harming them is the goal.

“Our work is conducted in Churchill, Manitoba and community members requested that we study the belugas in the least invasive way possible,” says Hudson.

“Non-invasive sampling is also important for stress studies because a lot of the techniques that have been used to study stress,” like drawing blood, “can cause a stress response.”