Endangered whales reveal signs of health trouble in their breath

Scientists used drones to sample the moist breath of North Atlantic right whales and showed that the microbes in that breath track the animals’ health. The new study focused on whales that gather in U.S. waters each spring.

The researchers worked in Cape Cod Bay, Massachusetts, over eight spring seasons and analyzed exhaled microbes against detailed health scores.

There are about 370 North Atlantic right whales remaining, so each data point helps guide care for a species on the edge.

Whale breath carries health clues

The research was led by Carolyn Miller, a large whale biologist at Woods Hole Oceanographic Institution (WHOI). Her research focuses on noninvasive ways to assess whale health from a distance using microbes and images.

At its core, the study examines the microbiome – the full suite of microbes living in a particular habitat. For whales, their breath carries bacteria and archaea released from the airways during a strong exhale.

Earlier work showed that drones can catch exhaled droplets and reveal a consistent set of breath microbes in large whales. That consistency makes the breath community a candidate health signal rather than random seawater noise.

“This is a major step forward in developing new approaches for monitoring wildlife health,” said Miller.

Collecting samples from whale breath

Teams flew small quadcopters at low altitude and briefly held sterile plates above the blowhole at the moment of exhale.

The approach is noninvasive, collecting samples without touching whales, and it avoids the stress that can come with boats and biopsy tools.

Researchers paired breath data with photogrammetry, the extraction of body measurements from photos. Vertical images from drones reveal whether a whale is thin or robust, and those measurements feed a body condition index.

The team used amplicon sequencing, DNA profiling based on a short genetic marker, to scan the microbial community.

The researchers targeted bacteria and archaea that are commonly seen in breath, skin, and the surrounding sea.

To compare across samples, the team tracked ASVs, unique DNA tags that separate closely related microbes. ASVs act like barcodes, letting models tally which microbes rise or fall with specific health scores.

What the models revealed

The analysis relied on elastic net regression, a machine learning method that selects the most useful predictors.

One model that combined an animal’s history with survival indicators performed especially well, offering strong predictions of overall health.

The model revealed clear microbial contrasts between the thinnest and most robust adult males. The underweight whale carried Clostridium and Peptoniphilus, while the healthier male carried Sediminispirochaeta and Candidatus Gracilibacteria.

Together, those shifts suggest a potential biomarker. The idea is not that a single germ causes illness, but that the whole pattern mirrors a body under strain or in good shape.

Patterns also shifted by year and by sex, with year-to-year predictions improving as the dataset expanded. In females, the signals likely change with reproductive state, which alters both energy demands and immune function.

Why this matters for conservation

Right whales face anthropogenic stressors, human caused pressures like ship strikes and fishing gear. With a small population, every adult and calf carries weight in long term recovery.

Managers need early warning indicators that show when a whale’s condition starts to slip. Breath sampling could plug into ongoing surveys and add health context to sightings and entanglement reports.

“This first-of-its-kind study provides a new window into the biology of some of the ocean’s most endangered species,” said Amy Apprill, associate scientist at WHOI.

Apprill noted that a breath based checkup is feasible because drones and microbiome tools are now standard in the field.

None of this replaces veterinary exams or visual checks from boats and planes. It adds a layer of evidence that can guide rapid responses and smarter protections in busy shipping corridors.

Future research directions

The next scientific step is validation with more whales across more places and seasons. Bigger and more varied datasets sharpen models and reveal which microbes stay informative in different conditions.

A key question is sensitivity to stressors, like short term gear drag or food shortfalls. There is independent evidence that blow communities shift during long fasting, hinting that breath signals track energetic status.

If breath models keep performing, they could flag whales that need closer watching during calving season or migration. They could also help test whether new policies actually reduce stress on the population.

Enrico Pirotta is a statistical ecologist in the Centre for Research into Ecological and Environmental Modelling at the University of St. Andrews (CREEM).

“Being able to measure whale health is a critical step towards assessing the effects of multiple stressors on these animals and, ultimately, come up with management solutions that can ensure their conservation,” said Pirotta.

The study is published in The ISME Journal.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–