Blue Whales, largest animal on Earth, mysteriously go silent

Blue whales, the largest animals on Earth, have gone silent due to food shortages. A study published in PLOS suggested that their vocalisation has reduced by 40% over a period of six years.

“The Blob,” a marine heatwave that began in the Pacific Ocean in 2013, raised temperatures by up to 4.5°F. This led to a massive decline in the anchovy and krill population. The warm water anomaly disrupted the marine food web and is considered the primary reason for the blue whales’ silence.

Kelly Benoit-Bird, the co-author of the paper, in an interview with National Geographic, said, “When we have these hot years and marine heatwaves, it’s more than just temperature.”

“The whole system changes, and we don’t get the krill. So, the animals that rely on krill are kind of out of luck,” she continued.

The toxic algae also caused poisoning of marine life through a phenomenon known as harmful algal bloom (HAB). The algae produce natural toxins, which are released into the water.

Filter-feeding marine animals such as mussels, oysters, and clams ingest and accumulate these toxins in their tissues. When larger marine animals like fish eat these shellfish, the toxins are transferred. This accumulation of toxins can lead to severe damage, illness, and even death in marine life.

Blue whales use sound to communicate. Researchers put a hydrophone on the sea floor off the California coast. The device collected the sound of various creatures.

The research finds that whales are spending too much energy searching for food, leaving them no time for singing. John Ryan, a biological oceanographer at the Monterey Bay Aquarium Research Institute, told whales are “spending all their energy searching”

“There’s just not enough time left over, and that tells us those years are incredibly stressful,” he added.

As the whale songs are essential for navigation, communication, and finding mates, the drop in vocalisation could lead to less mating and a significant decline in the population.

Scientists are concerned that this “ghostly silence” signals an alarming situation of climate change on the oceans.

What's the biggest animal as of 2025?

The Blue Whale is the biggest animal in the world.