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Meet the zombies of the deep

By Gavin Sherriff, 24 April 2014 12.00pm.

Amazing lives of the bone-eating zombies of the deep.

The oceans cover more than 70% of the planet’s surface, but what lies beneath is a mystery to most. Many of us don’t get much farther than a paddle at the seaside.

So what amazing creatures lie down in the deep? Stephen Palumbi knows better than anyone. In his book The Extreme Life of the Sea, co-written with his son Anthony, he describes a world that few people get to see first hand.

He told The Sunday Post The Honest Truth about life in the deep.

Why did you specialise in marine biology?

It’s like studying life on other planets — except this is our planet’s own oceans.

How deep in the ocean does life exist?

Life thrives in even the deepest parts, nearly 11 km beneath the surface. The unique problem down there is pressure. A polystyrene coffee cup would compress to the size of a shot glass by the pressure. If we were to go out of a submarine door that deep, the pressure would congeal the lipids and fats in our cells, and our nerves wouldn’t work.

Species manage to live in extreme habitats by having extreme adaptations. Creatures like the stoplight loosejaw, a deepsea fish that beams out red light in the dark sea so it can find its prey. The trick is only the loosejaw can see this shade of red, so it catches its prey unawares.

What are some of the other truly weird creatures down there?

If you pick up whale bones from the bottom of the sea, you might find an extra passenger — the

zombie bone worm, also descriptively called the snot flower.

It burrows into the bones because they’re full of oil and are a good food supply. Many worms can live in the same bones, and within weeks the bones of a large whale would be reduced to dust on the sea floor.

The inch-long snapping shrimps are built to shoot out pellets of water which travel so fast they leave a low-pressure wake behind them where bubbles form then collapse. The snapping sound is the collapse of the bubbles. The noise is so powerful it can stun prey and make a very small heat pulse in the sea hotter than the surface of the sun.

Why don’t fish in the coldest parts of the ocean freeze?

They’ve a protein in their blood that attaches to tiny ice crystals and keeps them from growing. Their blood is less salty than sea water, and when the ocean gets to -2° C, the salty sea doesn’t freeze but the less salty blood does. The anti-freeze proteins keep these ice fish from freezing up.

Is it true some creatures exist only next to scalding hot water from natural deep sea vents?

The Pompeii Worm lives with its tail in water which is the temperature of hot tea. But its head, only an inch away, lives in water that is icily chilly. How they make cells that can work at such different temperature is a secret locked in their genes.

What’s the commonest form of life in the sea?

Microbes. There is as much bacteria in a quart of water as there are people in India. Though tiny, the bacteria are so numerous that they control the chemistry of the oceans and the oxygen in our atmosphere.

The coelacanth was a fish previously known only from fossils. But it turned out many were still alive today. Any other living fossils out there?

There are four species of horseshoe crabs on the Atlantic coast of the USA and in SE Asia. You can find fossils of these creatures hundreds of million of years old that look just like the modern species. This is what a living fossil is — a form of life that hasn’t changed for a long time. The huge cephalopods that used to dominate the ocean have one type of living fossil — the clumsy nautilus, a squid-like animal living in a coiled shell in SE Asian reefs.

You mention creatures that live for centuries. How can you age them?

In the 1990s, Inuit natives captured a bowhead whale as part of their traditional hunt. The whale had a scar on its back inside which was a stone harpoon which had hit the whale long ago but obviously not killed it. No-one has thrown a stone harpoon at a whale for over a century so this one was far older than anyone thought whales could be.

Likewise, some deep sea fish in our current fisheries on the US west coast live to be over 100. Scientists have checked the centre of their ear bones for radioactivity.

Since the 1960s, when we dropped hydrogen bombs on coral reefs to test them, our oceans have had elevated levels of a radioactive element called Carbon-14. If a fish doesn’t have this in its inner ear, we know it must be older than that.

If you could travel back in time to see the seas at some time in the past, when would you choose?

About 400 million years ago, to see the ocean when the major prey were crab-like trilobites scuttling across the seafloor. The major predators were huge squid-like cephalopods that had heavy coiled shells. They filled their shells with gas so they could float. The biggest lived in coiled shells which measured six feet across.

Will the oceans be able to adapt to changes brought on by climate change and man’s influence?

The ocean life that thrives in the middle of our pollution isn’t very nice — bacteria, swarms of jellyfish, worms and slumbering species. We still have a choice, though, about whether we would rather have oceans full of dolphins and whales and codfish and lobsters and corals. All these species are still productive and capable of recovering. We can choose the future of the ocean: one where we continue to use it for recreation and food, or one where the small, explosive, weedy species take over.

• The Extreme Life of the Sea, Stephen and Anthony Palumbi, Princeton University Press, £19.95.