On most dives, the day’s adventure begins long before the descent into the sea. As the dive boat heads offshore, seabirds appear almost immediately. Gulls wheel overhead, shearwaters skim effortlessly across the waves, terns plunge after fish, while farther offshore an albatross may be gliding for minutes at a time without a single wingbeat. 

Tiny, shrimp-like crustaceans, lanternfish, squid, gelatinous drifters, transparent hunters, a multitude of fish and many more. Together, they ascend towards the surface in immense numbers, coming with the protection of darkness to feed in the richer waters above. Then, before dawn, they sink once more into the dimness of the depths. This happens every night in oceans around the world, yet most people have never heard of it.

Sharks and rays possess a remarkable ability: They can detect the faintest electrical impulses in the water. Hidden in their snouts are tiny sensory organs, called Ampullae of Lorenzini, filled with conductive gel. With them, a shark can sense the heartbeat of a fish buried beneath the sand, or detect the weak signals of prey hidden in darkness.

Even in murky water, even at night, even when prey is perfectly still. The electric field gives it away. It is a form of perception almost unimaginable to us, a way of seeing life itself.

A new study reveals how a team from the University of Victoria, working off the coast of Vancouver Island, has matched specific underwater voices to the species of fish that is making them. This achievement could improve the way we monitor and protect marine life.

A hidden soundscape

The study took place in Barkley Sound, a rich and complex marine environment where rocky reefs teem with life. Over the course of their research, scientists recorded more than 1,000 fish sounds and linked them to eight different species.

Scientists studying marine mammals off the Pacific coast of North America have observed an unusual interaction between two highly intelligent predators: killer whales and dolphins apparently hunting together.

The observations were recorded in British Columbia waters, where researchers documented groups of fish-eating resident orcas moving alongside Pacific white-sided dolphins during salmon hunts.

Researchers studying killer whales in the North Pacific have uncovered evidence suggesting that orcas may occasionally prey on other orcas, a behaviour rarely documented among the ocean’s top predators.

The clues come from two severed dorsal fins discovered on Bering Island in Russia’s Commander Islands. The fins bore clear tooth marks and other signs of feeding damage, indicating they may have been torn from killer whales and partially consumed.

Scientists have discovered evidence that orcas may eavesdrop on dolphins, potentially using the sounds produced during dolphin echolocation to help locate prey. The finding adds a new dimension to how marine predators may exploit the acoustic landscape of the ocean.

The art of becoming

The chameleon bends light through structure. Beneath its skin lie layers of cells that manipulate reflection, shifting crystal lattices to alter the wavelengths that reach our eyes. A mood, a rival, a shift in temperature, and forest-green suddenly blooms across its flanks.

For centuries, sailors and coastal communities have watched these great migrations in awe. And even now, with satellite tags, acoustic monitors and high-tech tracking at our disposal, the question of how whales navigate remains unknown.