Drones Sample Whale 'Snot' to Monitor Health of Endangered Right Whales

Researchers are using drones to collect the moist respiratory droplets—colloquially called "snot"—that erupt in the distinctive V-shaped blow of North Atlantic right whales. The noninvasive method captures microbes and other biological material from whale breath and may offer a practical way to monitor the health of these critically endangered animals.

Since 2016, a team led by Carolyn Miller of the Woods Hole Oceanographic Institution has flown drones carrying petri dishes through whale blows in Cape Cod Bay. By 2024 the researchers had gathered more than 100 samples from 85 individual whales. The samples were analyzed in collaboration with the University of St Andrews, New England Aquarium, SR³, and Whale and Dolphin Conservation, and the results were published in the ISME Journal (International Society for Microbial Ecology).

How the method works

When a whale surfaces and exhales, it releases a powerful spray of droplets. Pilots operate drones from boats at a distance, keeping aircraft in line of sight while minimizing disturbance to the animals. The drone passes a sterile petri dish or collection surface through the blow to capture microbes and organic material without approaching the whale directly.

Key findings

Pairing breath-sample microbiomes with long-term health and photo-identification records, the team identified links between the types of bacteria in the respiratory droplets and the whales' body condition—whether individuals appeared robust or thin. That relationship suggests breath microbiomes could be an indicator of nutritional status and general health in free-swimming right whales.

"It's really exciting that we're seeing that the microbes and the breath of these animals appears to be linked to their body condition," said Carolyn Miller, lead author and research associate at Woods Hole.

Conservation implications

The North Atlantic right whale population is critically small—estimated at about 384 animals, plus or minus roughly nine to ten. Noninvasive health monitoring tools are valuable complements to existing conservation efforts, which focus on preventing deaths from ship strikes and fishing-gear entanglements. Knowing which animals are undernourished or otherwise compromised can help managers prioritize interventions and better understand causes behind low reproduction rates.

Previous research indicates that adequate fat reserves are essential for female calving success and long migrations from feeding grounds in New England and Nova Scotia to calving grounds off Florida and Georgia. Underweight females may be one factor limiting population recovery.

Additional research

Scientists are also exploring whether the material collected on petri dishes contains enough DNA for genetic analysis and family mapping—similar to consumer ancestry services—though biopsy darts remain a more reliable DNA source at present. The drone-based approach builds on decades of photo-identification and health-survival modeling and offers a scalable, low-disturbance technique to expand monitoring across seasons and regions.

All drone work is conducted under strict federal permits and protocols intended to protect the animals and prevent harassment. The method traces its roots to earlier drone-conservation projects—including the "SnotBot" concept developed in collaboration with Ocean Alliance and engineering partners—and reflects growing use of aerial robotics in wildlife health assessment.

Further study will refine how microbial signatures correspond to disease, nutrition and reproductive potential, but the approach already provides a promising, less invasive window into the health of one of the world's most endangered large whale populations.

Author: Dinah Voyles Pulver