India's Elusive Porpoises Are Everywhere — If You Listen Closely

Imagine trying to count ghosts that only surface for a blink and live in murky water. That's essentially the job description for scientists tracking the Indo-Pacific finless porpoise, one of India's smallest and most camera-shy ocean mammals. No dorsal fin, a rounded head, and a penchant for shallow, muddy coastal waters make them notoriously difficult to spot.

Turns out, the trick isn't to look harder, but to listen. Because while these porpoises are masters of visual camouflage, they can't help but broadcast their presence to anyone with the right audio equipment.

The Sound of a Hidden World

These full-grown porpoises, clocking in at a modest 4.9 to 6.2 feet and 77 to 88 pounds, navigate their underwater world using echolocation. They ping out high-frequency sounds — unique to their species and entirely inaudible to human ears. Think of it as a personalized sonar system that doubles as a secret handshake.

Scientists decided to tune in. In a 2025 study off the Sindhudurg coast, north of Goa, researchers combined traditional visual surveys with acoustic (sound) surveys. The results were, shall we say, eye-opening – or perhaps, ear-opening.

The acoustic surveys detected porpoises four times more often than the visual surveys. Let that satisfying number sink in. It suggests these finless wonders might be far more common in Indian waters than anyone previously thought. Which, if you think about it, is both impressive and slightly terrifying, given how easily they've evaded official counts.

Isha Bopardikar, lead author from IISER Tirupati and Cornell University, put it plainly: relying solely on visual counts in India's low-visibility waters is a significant problem. It means our current population estimates could be drastically undercounting these creatures. We might be losing them before we even know how many there are.