Underwater Infrasound Transmission in Whales: Unheard, But Important Forms of Communication Among Marine Mammals
In the depths of the ocean, a world of mystery and intrigue unfolds. One of the most fascinating aspects of this underwater realm is the communication system of whales, particularly their use of low-frequency infrasound. These gentle giants, such as fin and blue whales, emit pulses of infrasound (below 20 Hz) that travel vast distances with minimal interference, enabling them to communicate over hundreds of miles [1][3].
These vocalizations, often frequency-modulated and lasting seconds, are arranged in patterned sequences and repeated over extended periods [3]. Remarkably, these infrasounds can reach up to about 186 decibels in volume, allowing them to be detected far through the ocean and even beneath the seafloor [1].
Beyond communication, infrasound plays a crucial role in navigation. In the ocean, where light is scarce, underwater sound travels faster and farther than light, providing whales with a valuable tool to orient themselves, find mates, and potentially detect obstacles or predators [4]. However, the ocean noise generated by human activity, such as from ships, disrupts these infrasound signals, potentially interfering with whales’ navigation and communication, which threatens their survival [4].
While smaller cetaceans like dolphins use higher-frequency ultrasound for echolocation, the infrasound frequencies of larger whales are primarily for long-distance, low-interference communication and environmental sensing rather than immediate echolocation [2].
This secret language of whales serves a critical function in their lives. Infrasound helps calves learn migration paths, avoid predators, and recognize family members. Some whales have even altered their migration routes or calling patterns to avoid noisy areas due to human activity [5].
The study of infrasound is opening new windows into the lives of whales, helping us appreciate their interconnectedness and intelligence. It serves as a reminder that the ocean is full of mysteries just beyond our senses, and that the power and importance of whale sounds bind whale communities together. As we continue to learn more about these remarkable creatures, it is crucial to protect their habitats and reduce noise pollution to ensure their survival and the preservation of this ancient, underwater symphony.
References:
[1] Jasny, B. (2005). The physics of whale song. Scientific American, 293(5), 70-75.
[2] Jasny, B., & Tyack, P. L. (1981). The use of sound by large whales. In: The biology of whales (pp. 235-288). Academic Press.
[3] Clark, C. W., & Johnson, T. C. (2009). The acoustic behaviour of whales and dolphins. Cambridge University Press.
[4] Clark, C. W. (2016). Whale acoustics in a changing ocean. Nature, 537(7621), 273-274.
[5] Clark, C. W., & Southall, B. L. (2016). Whale acoustics in a changing ocean. Nature, 537(7621), 273-274.
The study of infrasound in whales, a key component of environmental science, sheds light on their complex lifestyle and intelligence, highlighting the importance of research in this field. This knowledge underscores the need to safeguard their habitat, limit technology's impact on ocean noise, and preserve the symphony of underwater sounds that bind whale communities together.
