Basking Shark

Fascinating facts about the Basking Shark

• A basking shark's mouth can open 1 metre wide — wide enough to swallow a person whole — yet it eats nothing bigger than a grain of rice. Every hour, it filters 2,000 tonnes of seawater through its gill rakers, extracting microscopic plankton. This is the second-largest fish on Earth hunting the tiniest prey, a contradiction that reveals how abundance, not size, shapes what a predator can be.
• For months at a time, basking sharks vanish. Scientists tracked them diving 3,000 metres below the surface into pitch-black water where sunlight never reaches, then climbing back up in cycles. Why they do this remains a mystery — they may hunt in the deep, rest, or migrate using pressure cues — but it means the second-largest shark on the planet lives a secret life we're only beginning to glimpse.
• A female basking shark can be 12 metres long and weigh as much as a double-decker bus, yet she produces only 4 to 7 pups in her entire lifetime. Some may carry babies for years — gestation periods longer than human pregnancies — before giving birth to live young. This brutal fertility rate means a single dead female erases decades of population growth.
• In the 1950s and 1960s, Norwegian and Scottish hunters killed basking sharks for their liver oil, which was used to machine guns during World War II. Fishermen took over 100,000 in just two decades, crashing populations so severely that the species still hasn't recovered 70 years later. Their slow reproduction means a single hunting season can set a species back generations.
• Basking sharks migrate across entire ocean basins — tracked individuals have journeyed from Ireland to Brazil, a distance of 9,600 kilometres. Yet they navigate an ocean with no landmarks, no coastline to follow, using cues scientists still don't fully understand. Their ability to cross open water while invisible to us suggests we've mapped only the surface of how sharks navigate the planet.

At a glance

About the Basking Shark

In the dark, mysterious depths of the ocean, the basking shark glides effortlessly, its immense, filter-feeding maw agape as it strains the plankton-rich waters for sustenance. As it moves through the waves, its slow, deliberate pace belies a quiet majesty, its gray, streamlined form undulating through the blue expanse like a spectral apparition. Despite its endangered status, this gentle giant remains an awe-inspiring sight, a testament to the wonders that still linger in the uncharted vastness of our planet's oceans.

Discover more wildlife