2023-04-16 09:07:00
The surface of the Earth, also called Terra, is 72 percent – almost three-quarters! – from sea and ocean. It would actually be much more logical to say that the surface of the planet Aqua consists of 28 percent – more than a quarter – of land. But the observation is made by intelligent life forms that inhabit the relatively modest area of land, which almost automatically elevates it to a frame of reference.
Land is the norm, sea the exception. Since humanity to the furthest reaches of unknown land penetrated and mapped everything, we think we know the planet. But nothing is less true. Of that 72 percent sea, by far the largest part is deep ocean, of which we know even less than about the surface of the moon.
I remember the fuss when a complete ecosystem was first discovered at the so-called black smokers, deep-sea volcanoes where water with a temperature of several hundred degrees Celsius escapes at a depth of kilometers, in which just about everything that Greenpeace wants to ban has dissolved. A glowing soup full of sulfur and heavy metals.
As if you want to investigate the Sahara with a compact camera
Bacteria, crabs, sea anemones, tube worms and large mussels live there. You can get there with tiny submersibles. But the range of such observations in the deep sea is like looking at the entire Sahara with a point-and-shoot camera. Occasionally a snapshot of a bleached camel skull, but the rest eludes you.
A stroke of luck was the video that Australian researchers made at a depth of 8300 meters of a number of bright white fish in a trough off the coast of Japan. They turned out to be snail dolphins, which had descended on a dead fish that had been attached to a protrusion of the submarine as bait.
Snail dolphins are small fish with a relatively large head and a laterally flattened body with elongated fins. They look a bit like king tadpoles. Or on snails, hence the strange name snail dolphin. They are called in English permanent, sea slug, which of course is totally confusing. These fish also occur sporadically in the Netherlands: the snail dolphin Liparis liparis and the rare little snail dolphin Liparis montagui.
Deep sea dark
Living at a depth of 8300 meters must not be easy. The water pressure is about 800 atmospheres, it is pitch dark (actually the term deep-sea dark would be more appropriate) and there is not much food to be found. Naturally, with a lack of light, there is no plant growth, not even unicellular. So there is little life, presumably the animals mainly eat what falls dead from higher water layers.
In the video we see pale pink lobed fish with a mouth like an axolotl and small black beady eyes that they can’t use at all. With graceful wave movements of the abdomen they whirl around the bait.
They show us two things. Firstly, that nature is really everywhere on our planet, not only on the sunlit and freshly rained surface of the earth, but even in the most unimaginable places. And secondly, that we still don’t know a lot about it unknown water.
Jelle Reumer is a paleontologist. Every week he discusses an animal that makes the news for Trouw.
1681638867
#lot #unknown #life #deep #sea #glimpse