无尽汪洋 08

Some of these ocean vagrants may offer protection,

like this pyrosome is doing for the shrimp.

In the world's deepest ocean,

averaging over two and a half miles deep,

new species are constantly being discovered.

Like this seahorse, never filmed before.

At dawn,

these little-known creatures retreat into the safety of the abyss.

But there are some predators that can follow them down.

Short-finned pilot whales are accomplished deep-sea divers.

Leaving the barren upper layers behind,

they can swim over half a mile down

and use their sonar to track the huge shoals of squid.

But they too are being tracked.

Oceanic whitetip sharks, three metres long,

and completely at home in the open ocean.

They may not be able to dive deep enough

to catch the squid themselves,

but that won't stop them hanging around for scraps.

Or maybe they're sizing up the calf.

This one, however, is well guarded by the bulls.

But in the endless blue,

where the odds of finding a meal are so low,

even the slimmest opportunity is worth a try.

Perhaps this is why

the oceanic whitetip is thought to be responsible

for more attacks on shipwrecked sailors than any other shark in the Pacific.