Most of the life in the ocean can be found in the first zone, which begins at the surface and goes down to about 200 metres. Because there is sunlight at this level, plants are able to grow. Marine animals such as dolphins, sharks, sea turtles and sea lions, and of course a variety of fish, live in the sunlight part of the ocean. It is difficult to hide from other animals in the area, but many species have adapted by becoming dark on the top and light on the bottom. This makes it hard to see them against the dark water below and the blue sky above.
The second starts at 200 metres and goes down to about 1,000 metres. Some sunlight can reach this level, but it is not enough for plants to grow. Because this zone is relatively dark, many of the creatures that live here are able to make light with their body. The light from these animals makes the water look like a sky with moving stars in it.
The third zone is dark. This place, about 3,000 metres deep, may not seem a likely habitat (栖息地), but there are more creatures here than one might think. Most of the animals that live here are black or red because of the lack of light. At this depth, a slow shower of what looks like snow is falling. This phenomenon, called “marine snow”, is actually nutrients falling towards the bottom of the ocean. It is source of food for the creatures that live in the deep.
Below 4,000 metres, the temperature is near freezing and there is no light at all. In fact, the zone is so dark and empty that scientists named this zone after the Greek word for “no bottom”. There is not much life to be found in this cold and unpleasant part. But some creatures manage to survive here despite the high water pressure.
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