WASHINGTON, Sept. 9, 2025 – In a groundbreaking discovery, researchers have documented rare beaked whales in the Foz do Amazonas Basin off northern Brazil. Known for their elusive nature, beaked whales are among the least understood cetaceans, largely due to their deep-diving capabilities and offshore habitats.
Beaked whales, which include 24 known species, are renowned for their cryptic behavior and ability to dive as deep as 3,000 meters for over two hours. This makes them difficult to study, as they spend minimal time at the surface. The recent study, published in the Journal of the Acoustical Society of America (JASA), aims to shed light on these enigmatic creatures.
Unveiling the Mystery of Beaked Whales
The research was a collaborative effort involving scientists from Instituto Aqualie, Juiz de Fora Federal University, Mineral Engenharia e Meio Ambiente, and Santa Catarina State University. “The motivation for this research arose from the need to expand knowledge on cetacean biodiversity in Brazilian waters, with particular attention to deep-diving species such as beaked whales,” explained Raphael Barbosa Machado, one of the study’s authors.
Using passive acoustic monitoring, the team employed hydrophones and autonomous recorders operating at frequencies between 192-384 kilohertz. This technology enabled them to capture nine audio recordings and visually spot the whales on four occasions. Their findings revealed at least three different species of beaked whales in the region.
Challenges in Studying Elusive Cetaceans
Beaked whales produce unique echolocation pulses that are not typically emitted at the surface, complicating efforts to link sounds with specific species. This study marks the first documentation of acoustic parameters for beaked whales in Brazilian waters, offering new insights into cetacean biodiversity in northern Brazil.
“This study provides the first documentation of acoustic parameters of beaked whales in Brazilian waters, while also contributing new information on cetacean biodiversity in northern Brazil,” Machado noted. The research underscores the potential of acoustic monitoring as a tool for studying elusive marine life.
Implications for Conservation
The discovery has significant implications for conservation efforts. As Machado and his team continue their research, they hope to enhance the understanding of the western South Atlantic Ocean’s biodiversity, an area that remains poorly studied. “As the number of detections increases — particularly simultaneous visual and acoustic records — our ability to reliably associate specific acoustic signals with visually confirmed species will also improve,” Machado emphasized.
“Addressing these knowledge gaps is essential for informing public policies and guiding conservation and management efforts aimed at safeguarding these elusive species,” Machado added.
Looking Ahead: Future Research and Conservation Efforts
The study’s findings highlight the importance of continued research in the Foz do Amazonas Basin and similar regions. By expanding the knowledge of cetacean biodiversity, scientists can better inform conservation strategies and public policy, ultimately aiding in the protection of these rare marine mammals.
The announcement comes as global attention increasingly focuses on marine conservation, with many species facing threats from climate change, pollution, and human activities. The work of Machado and his colleagues represents a crucial step forward in understanding and preserving the delicate ecosystems of the ocean’s depths.
As research progresses, the hope is that these efforts will lead to more comprehensive conservation measures, ensuring the survival of beaked whales and other deep-diving cetaceans for future generations.
