49 facts
you can use
at dinner.

A big male's dorsal fin can stand 1.8 m tall — taller than most adults.

A blue whale's blow shoots 9 metres into the air — you can spot it from kilometres away.

The bumps on a humpback's head are called tubercles, and each one grows a single hair used to sense the water.

Ambergris — a rare, waxy substance from a sperm whale's gut — was once worth more than gold to perfume makers.

Narwhals can hold their breath for around 25 minutes under solid ice.

Beluga comes from the Russian word for white.

One gray whale was tracked swimming from Russia to Mexico and back — nearly 23,000 km, the longest migration ever recorded for a mammal.

They can hold their breath for around 30 minutes.

They can move surprisingly fast on ice — fast enough that Antarctic researchers keep their distance.

They carry scientific instruments: tagged elephant seals have collected huge amounts of the ocean temperature data we have from under Antarctic ice.

They've been around, largely unchanged, for roughly 15 million years — sometimes called living fossils.

They can sleep floating at the surface with one flipper in the air — that flipper is a heat exchanger, warming or cooling the blood.

Pups are born nearly a metre long and 20 kg — bigger than many adult harbor seal pups.

Their blubber can be 15 cm thick — enough to survive water just above freezing.

They're the smallest marine mammal and the heaviest member of the weasel family.

A manatee's flipper has fingernails — a leftover from its land-mammal ancestors.

The grey saddle patch behind the fin is as unique as a fingerprint, so researchers use it to name every individual.

Their earwax builds up in layers like tree rings, and scientists read it to work out a whale's age and stress.

A breaching humpback throws its whole body clear of the water. Nobody is completely sure whether it's communication, parasite removal, or just fun.

Moby Dick was based on a real white sperm whale, Mocha Dick, and on the sinking of the whaleship Essex in 1820.

Their skin, called muktuk, is an important traditional Inuit food and is unusually rich in vitamin C.

One captive beluga, NOC, spontaneously altered his calls to imitate human speech patterns closely enough that a diver climbed out of the water thinking someone had shouted at him.

They have no dorsal fin, just a low hump followed by a row of bumps called knuckles.

A resting harbor seal's heart slows so much that its body can send nearly all its oxygen to the brain and heart alone.

Hydrurga leptonyx means water worker with a slender claw.

Their blood holds so much oxygen that they can shut down blood flow to most of the body while diving.

Monk seals moult their entire coat and the top layer of skin once a year, all at once.

Sea lions can be taught abstract logic tasks that most animals fail.

They sometimes eat northern fur seal pups and harbor seals, which is unusual for a sea lion.

Males inflate air sacs in their necks to make a deep bell-like gonging sound underwater during breeding season, and can use those sacs as a built-in flotation pillow while they sleep in the water.

A raft can be a couple of otters or, in Alaska, over a thousand.

They have only six neck vertebrae instead of the usual seven, so they turn their whole body to look around.

Orcas are the second most widely distributed mammal on the planet. First place: us.

Roughly 10,000–25,000 blue whales are left, down from perhaps 350,000 before whaling.

Their song only travels in the low frequencies — but it can carry across an entire ocean basin.

Their heart rate drops to a handful of beats per minute on a deep dive to save oxygen.

Monodon monoceros means one tooth, one horn.

They can swim in water only slightly deeper than their own body.

Baby gray whales drink around 190 litres of milk a day.

Their eyes have a reflective layer behind the retina, like a cat's, for seeing in dark water.

Only orcas hunt adult leopard seals.

A bull's chest shield — thick, scarred, wrinkled skin — is armour built for fighting.

Pups are born black and lose that coat within their first few weeks.

Their whiskers, like a seal's, can track a fish through murky water.

A rookery is for breeding; a haul-out is just for resting. Sea lions use both, for different things.

A walrus can slow its heart rate right down to survive long, cold dives.

Some sea otters specialise: one individual will eat mostly crabs while its neighbour eats mostly clams, and mothers teach the preference to their pups.

Steller's sea cow, a 9-metre Arctic relative, was hunted to extinction within 27 years of Europeans finding it.

No wild orca has ever been recorded killing a human.