Definitely the place to visit if you think you’ve seen it all. The flattest, vastest, strangest, least – explored place on the planet where many of the creatures will be unknown, unnamed and bizarre.
Getting there is the problem. More people have made the trip into space than have ever visited the abyssal plains. But don’t despair. This week the Southampton Oceanography Centre ordered a remotely operated vehicle that can make the voyage. It won’t actually take you there, but it might allow you a distant peek.
So where are the abyssal plains? At the bottom of the ocean. They cover more than a third of the Earth’s surface and are utterly flat, thanks to a gentle rain of sediment that constantly falls from the surface thousands of metres above. They are cold, dark and so deep that only specialised diving vessels can go there.
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Why bother exactly? Until recently no one would have seen the attraction. People assumed that the abyssal plains were underwater deserts, nothing more than vast expanses of lifeless mud. There were even plans to store nuclear waste there. But now we know that the biodiversity of the plains is something special. It may even outstrip that of a tropical rainforest.
What’s down there? The mud floor turns out to be covered with little mounds, holes and tracks. Thousands of species of nematodes and polychaete worms live in the mud, along with crustaceans such as amphipod shrimps and isopods. The tracks belong principally to huge numbers of sea cucumbers, slowly trawling the bottom. It is too dark for plant life so everything that lives there is dependent on what descends from above.
Occasionally something big falls and attracts a big crowd. Researchers who have seen a dead whale reach the ocean floor come back with stories that make life in the Serengeti seem placid. First on the scene are amphipods. They’re like large shrimps but with strong, sharp jaws that slice away chunks of flesh. Within hours, thousands of them will be cutting the whale to pieces.
Next come creatures that can swim quickly and have a keen sense of smell: rat-tailed fish and the primitive eel-like hagfish, which uses its rasping tongue to rip into the whale. Later at the feast are molluscs, starfish, brittlestars, polychaetes, crabs, and of course, sea cucumbers.
Is there more to see? We barely know. One survey in the 1980s found 90,677 creatures belonging to 798 species – nearly 60 per cent of them new to science – in an area of 54 square kilometres. And there are still 300 million square kilometres to explore.