Baleen Whales’ Singing Abilities and the Impact of Noise Pollution on Marine Communication
Whales, the majestic creatures of the ocean, have long fascinated scientists and researchers. Their ability to communicate through songs and calls has been a subject of great interest. A recent study published in Nature has shed light on how baleen whales, including species like sei, common minke, and humpback, are able to produce their vocals underwater. This discovery not only deepens our understanding of these magnificent creatures but also highlights the impact of noise pollution on their ability to communicate and thrive as a species.
When whales returned to the ocean from land millions of years ago, they underwent major adaptations to make vocal communication possible underwater. The study reveals that baleen whales use specialized larynxes to communicate with each other beneath the ocean’s surface. These larynxes have unique structures that allow the whales to create massive air flows back and forth when they breathe in. Unlike toothed whales that evolved a nasal vocal organ, baleen whales have developed adaptations that enable them to produce sound and recycle air while preventing the inhalation of water.
The frequency at which baleen whales sing is likely to be low, with a maximum frequency of 300 hertz. However, this puts their communication abilities at risk due to human activities such as shipping. Shipping vessels generate noise between 30 hertz and 300 hertz, which overlaps with the frequency range of whale communication. As a result, the noise from shipping activity reduces the range in which whales can effectively communicate, potentially causing stress and disruption to their natural behavior.
“We think that this mechanism is an ancestral mechanism that these animals have used to make very low frequency sounds in an environment where sound is the only way of communication and the only way…to find animals that are very far apart,” explains Coen Elemans, a professor of sound communication and barrier at the University of Southern Denmark.
Whales live in a “completely acoustic world,” unlike humans who heavily rely on sight, as Sharon Livermore, director of marine conservation at the International Fund for Animal Welfare, points out. This reliance on sound makes them vulnerable to noise pollution, which is often invisible to the human eye but has a significant impact on marine life.
The threat posed by vessel noise pollution and shipping intensity is a real concern for large whales. Bekah Lane, a cetacean field research specialist at The Marine Mammal Center, highlights that constant shipping noise dominates the ocean soundscape and raises stress levels in some species. The critically endangered North Atlantic right whale is particularly affected by this noise pollution.
The ability to communicate and be heard is crucial for whales’ survival, says Joy Reidenberg, a professor of anatomy at the Icahn School of Medicine at Mount Sinai. Singing is just one form of communication among whales, primarily performed by males in tropical waters as they search for mates. Other forms of communication, such as calls, are used by mothers and other whales attempting to communicate with individual whales.
The recent deaths of five North Atlantic right whales have renewed calls for federal shipping regulations. Environmental groups have filed a federal lawsuit to finalize shipping speed rules proposed in 2022, which would require mariners off the East Coast to slow down to reduce the risk of injury or death to these endangered whales. However, finding a balance between protecting marine wildlife and meeting consumer demands for fast shipping poses a complex challenge.
“We need to think critically about how our consumer choices and purchasing power can have real consequences for marine wildlife,” emphasizes Bekah Lane.
Efforts are being made to find solutions that better protect whales. Ongoing research and collaboration with local harbor safety committees, the maritime industry, and government agencies are essential. However, studying live whales remains a challenge due to their size. Researchers hope that future technology, such as remote-operated vehicles capable of getting close to singing whales and performing ultrasounds, will provide valuable insights.
As we continue to explore the depths of the ocean and unravel the mysteries of marine life, it is crucial to recognize the impact of human activities on these magnificent creatures. Preserving the acoustic world of whales and mitigating noise pollution is not only vital for their survival but also for maintaining the delicate balance of our oceans.