Whales, the ancient navigators of the ocean, don’t just sing for communication—their vocalizations form an intricate signaling system crucial for reproduction, navigation, and hunting. A recent study revealed that whale songs significantly decrease after marine heatwaves, correlating with a decline in prey abundance.
But why does this matter? To fully understand climate change’s impact on whales and marine ecosystems, we must dive deeper into how whales use sound and what hidden signals lie within the ocean’s acoustic landscape.
How Do Whales Use Sound?
Whales are masters of acoustic communication, utilizing a broad frequency spectrum that allows different species to occupy their own “communication channels.”
🔹 Blue whales produce low-frequency sounds (10-40 Hz), capable of traveling thousands of kilometers through the ocean’s deep sound channels. This allows them to communicate across entire ocean basins.
🔹 Humpback whales are famous for their complex songs, evolving over time. Their vocalizations range from deep moans to high-pitched trills and can last up to 30 minutes, repeating with slight variations.
🔹 Fin whales use frequencies between 20 and 80 Hz, often repeating simple rhythmic patterns that create echoing reverberations in deep waters.
🔹 Sperm whales don’t "sing" but produce intense clicks (2-40 kHz) for echolocation, helping them locate prey at depths beyond 1000 meters.
Why Do Whale Songs Decline After Marine Heatwaves?
Researchers from the Monterey Bay Aquarium Research Institute (MBARI) analyzed whale songs recorded from 2015 to 2021, correlating them with prey abundance (krill, anchovies, and sardines). They discovered that during extreme ocean warming events (such as marine heatwaves), whales vocalized less due to food scarcity.
Reasons for decreased vocalization:
🔹 Energy conservation – Singing requires energy, and when food is scarce, whales may reduce their vocal activity to conserve resources.
🔹 Disrupted migration routes – If prey shifts locations, whales must spend more time searching for food, reducing their social interactions.
🔹 Changes in sound propagation – Warmer waters alter sound speed, potentially affecting long-distance communication.
Whale Songs as an Indicator of Ocean Health
This discovery highlights that whale vocalization can serve as a sensitive indicator of oceanic changes. When whale songs fade, it may signal prey depletion, ecological shifts, and climate-related disruptions.
What’s Next?
Machine learning and acoustic sensors are now being used to automatically detect and analyze whale songs, providing real-time insights into marine ecosystem health.
Monitoring whale vocalization could become an early-warning system for oceanic environmental changes, aiding conservation efforts.
Advances in acoustic technology and frequency analysis could deepen our understanding of whales and their role in the ocean’s vast communication network.
Whales sing when the ocean thrives. And when their voices fall silent, it’s a reminder that the ocean needs our attention and care.