They are also known as the aquatic ecosystems. It has the unique features which do not resemble the other biomes. They are of different types. They may occur in oceans, lakes and rivers, marshes and the streams.
The ocean biome is also known as the marine biome. It occurs around two third of the earth area. The salts are higher in concentration and have a lot of sodium and chloride ions. The concentration of salt is around 4 percent. The other minerals which are present include the magnesium and calcium. The salinity remains almost constant. It may vary in the red sea, river mouths and poles. The essential nutrients are deficient. It affects the productivity of ocean. It is one thousand kilo calorie per meter square per year. It is much less than the terrestrial biome. The temperature at the surface of ocean is around 30 degree Celsius. It occurs near the equatorial regions. At the poles the temperature is around less than zero degrees Celsius. In the deeper areas the temperature does not differ much. There are hot and cold currents in the ocean. The rainfall and geographical location almost play no role in the oceanic habitat. The factors which play an important role are the drainage of rivers, distance from shore and the depth of water. There are many vertical zones which are present in the ocean and they depend upon the availability of sunlight. The upper layer of ocean receives a good amount of sunlight. It extends about 200 meter. It is known as a photic zone. The lower layer of ocean receives a less amount of sunlight. It extends about 200 to 2000 meter. It is known as an aphotic zone. There is a complete darkness below 2000 meter extending up to the 10000 meter and this is referred as an abyssal zone. The ocean basin is known as a wash basin. It is also referred as an inverted hat. It is divided into different parts. These are known as continental shelf, continental slope and ocean floor. The continental shelf is a gradual sloping area which occurs in the sea shore. It extends from the coastline to up to 150 kilometer in the sea. It is 200 meter deep and the slope is almost flat. It has an inclination of 0.1 degree and shows high productivity. The continental slope is a slanting area and connects the edge of the slope to sea. It is not at all flat and has an inclination of 3 to 6 degree. It has ridges, trenches and basins. The sand is brought by the river. The bottom of the ocean is formed by the ocean floor. It is horizontal in shape and has multiple trenches. It can extend from 6000 to 10000 meters. The ocean basin has many environmental zones. They are of mainly three types littoral, benthonic and pelagic. The littoral zone occurs at the sea floor in the area of continental shelf. The benthonic zone occurs at the sea floor in the area of continental slope including photic and aphotic zone. The pelagic zone occurs in the water of ocean. They are divided into different types. They can be epipelagic, mesopelagic and bathypelagic.
