.Article Title: Life in the Ocean
Author: James W. Nybakken and Steven K. Webster
- 71% of earth's surface is covered by oceans.
- Life emerged from the oceans 4 billion years ago.
- Researchers have studied less than 10% of the ocean and only 1% of the deep ocean floor.
- One and half million have been discovered, but total estimates range from 5 to 50 million.
- Some creatures glow in the dark, many are boneless, most plants grow fast and die young.
- Seawater is 800 times more dense than air; therefore marine organisms and food can float in water.
- Water absorbs light differently than air; a few hundred meters down, there is no light and no photosynthesis.
- Ocean does not contain much plant life because of lack of phosphorus and nitrogen.
- Surface waters are warm in summer and cold the rest of the year.
- Below well-mixed surface layer is a narrow zone , called the thermocline, that separates the warm surface from the cold, and therefore heavier water beneath.
- This cold, heavy water that is the key to the food chain. It receives a constant amount of organic matter from above. Deep, chilly water is richly supplied with nutrients. No photosynthesis takes place there because no light reaches it, therefore few organisms take advantage of this abundant nourishment.
- Surface water is often barren of nutrients because the sun-loving organisms depleted them.
- Temperature and depth play an important role in the availability of oxygen.
- In the ocean, oxygen only enters at or near the surface.
- Deep waters sank carrying large amounts of dissolved oxygen.
- Species that live in the deep sea feed on an unending shower of organic particles, called marine snow. As it sinks downward, organisms feed on it so there is less and less as it falls. The diminishing supply means that there are fewer consumers at a greater depth.
The oceans are a big part of Earth, covering 71% of the planet's surface. Not only do they provide food for humans, they are the habitats for many marine species. Scientists have only studied 10% of the ocean and only 1% of the deep ocean. 1 and a half million species have been discovered, but total estimates range from 5 to 50 million. The planet's oceans are totally different than the planet's lands. The oceans hold some of the oddest species of plants and animals that can survive deep in the ocean without sunlight and oxygen and can withstand great pressure and low temperatures.
I am interested about the undiscovered species after reading this article. Scientists have only made a small leap in the discovery of animals and plants in the ocean. Who knows what could be down in the deep depths of the ocean? But the reason why scientists can not penetrate the deep waters is because the pressure is too high and the temperatures too low. Also it is too dark down because sunlight isn't able to reach so far down into the ocean.