Scientists are testing the hearing ability of baleen whales for the first time
In a study published in the journal Science, researchers successfully tested the hearing of baleen whales for the first time. The controversial study, conducted in 2023, involved the capture of two young minke whales off the Norwegian coast. The whales, each about 3 meters long and weighing about a ton, were fitted with gold-plated electrodes on their skin to monitor brain responses to different sound frequencies. The findings suggest that baleen whales can hear ultrasonic frequencies much higher than previously thought, an ability thought to aid in evading predators, especially killer whales.
The project, also called the Minke Whale Hearing Project, has drawn criticism from conservation groups and scientists. Concerns were raised about the stress and potential harm the whales experience during their temporary captivity. The Whale and Dolphin Conservation sent an open letter to the Norwegian government in 2021 urging the project’s cancellation, according to NBC News report. Critics argued that alternative, non-invasive methods could yield similar findings without compromising the animals’ welfare.
Despite opposition, the study was conducted under strict protocols, Brandon Southall, a maritime acoustics consultant, told NBC News. He noted that the project met best practices and contributed valuable insights into ocean noise management policies under regulations such as the Marine Mammal Protection Act.
Methodology and challenges in capturing and testing whales
To facilitate testing, a complex trapping system was set up along the migratory route of minke whales near Norway’s Lofoten Islands, according to the study. The team used more than a mile of nets to guide the whales to a canal, where they were briefly held in a fish farm. The monitoring was carried out by a team of 12 to 15 staff, including veterinarians. Blood samples, satellite tags, and neurological data were collected during 30- to 90-minute sessions before the animals were released.
National Marine Mammal Foundation Principal Investigator Dr. Dorian Houser highlighted the welfare measures during the interview with NBC News. He reported that the tagged whales resumed normal behavior after release, but one untested whale died after becoming entangled in a net during a storm.
The results of the research may influence future policy to combat underwater noise pollution. However, as Susan Parks, professor of biology at Syracuse University, noted to NBC News, the limited size and scope of the sample highlight the need for further research to understand baleen whales’ hearing abilities across species and age groups.
