How Baleen Whales’ Ability to Sing Underwater is Impacted by Shipping Noise Pollution, Study Finds
Whales are known for their enchanting songs that resonate through the depths of the ocean. But a recent study has shed light on how noise pollution from shipping activity can disrupt these majestic creatures’ ability to communicate and thrive. The findings provide valuable insights into the impact of human activities on marine mammals.
According to a study published in Nature, when whales transitioned from land to sea, they underwent significant adaptations to enable vocal communication underwater. Researchers discovered that baleen whales, including species like sei, common minke, and humpback whales, possess specialized larynxes that allow them to communicate effectively beneath the ocean’s surface.
Coen Elemans, a professor of sound communication and barrier at the University of Southern Denmark and author of the paper, explained that these larynxes have unique adaptations that enable the whales to generate massive air flows while breathing in. Unlike toothed whales, which evolved a nasal vocal organ, baleen whales have specialized structures that facilitate sound production and air recycling while preventing water inhalation.
However, the study revealed that the frequency at which baleen whales sing is likely to be low, with a maximum frequency of 300 hertz. This puts their communication abilities at risk due to human activities such as shipping, which generates noise within the same frequency range. Shipping vessels typically produce noise between 30 hertz and 300 hertz, significantly overlapping with the whales’ communication range.
The presence of shipping noise restricts the range over which whales can communicate, potentially causing stress and hindering their ability to find mates and locate other individuals. Joy Reidenberg, a professor of anatomy at the Icahn School of Medicine at Mount Sinai in New York City, emphasized that this mechanism is crucial for these animals to communicate over long distances in an environment where sound is the primary mode of communication.
Unlike humans, who heavily rely on sight, whales inhabit a “completely acoustic world,” as described by Sharon Livermore, director of marine conservation at the International Fund for Animal Welfare. This acoustic world is now under threat from vessel noise pollution and shipping intensity, which pose significant risks to large whales.
Research has shown that constant shipping noise dominates the ocean soundscape and elevates stress levels in certain species, particularly the critically endangered North Atlantic right whale. Livermore highlighted that underwater noise is an invisible pollutant to the human eye but has detrimental effects on marine life.
Apart from singing, whales employ various other forms of communication. Reidenberg, who peer-reviewed the study, explained that males typically sing in tropical waters to attract mates. Additionally, whales use calls, which differ from singing and are often utilized by mothers and other individuals attempting to communicate with specific whales.
The ability of whales to hear and be heard is vital for their survival. However, recent incidents involving the deaths of five North Atlantic right whales have reignited calls for federal shipping regulations. Environmental groups have filed a federal lawsuit to enforce shipping speed rules proposed in 2022, which would require mariners off the East Coast to reduce their speed to minimize the risk of injury or death to these endangered creatures.
Nevertheless, the issue becomes more complex due to consumer demand for fast shipping of goods across oceans. Bekah Lane, a cetacean field research specialist at The Marine Mammal Center, emphasized the need for critical thinking regarding consumer choices and their consequences for marine wildlife.
To better protect whales, ongoing research efforts must be combined with collaboration among local harbor safety committees, the maritime industry, and government agencies. Lane stressed the importance of finding solutions through collective efforts.
Looking ahead, researchers hope that advancements in technology will enable them to study live whales more effectively. Currently, studying these massive creatures is challenging due to their size. However, technologies like remote-operated vehicles that can approach singing whales and perform ultrasounds would be ideal for further understanding their vocalizations.
In conclusion, the recent study on baleen whales’ ability to sing underwater and the impact of shipping noise pollution highlights the vulnerability of these magnificent creatures. It underscores the urgent need for measures to mitigate noise pollution and protect marine mammals, ensuring their continued existence in our oceans.