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The aquatic biome makes up the largest part of the biosphere, covering nearly 75% of the
Earth’s surface and consists of the freshwater biome and the marine biome. Freshwater regions consist of ponds, lakes, streams, rivers, wetlands and marine regions include oceans, coral reefs and estuaries. Marine biomes generally have salt concentrations that average 3%, whereas freshwater biomes are usually characterised by a salt concentration of less than 0.1%. The aquatic biome is probably the most important of all the biomes as it provides us with water, a major natural resource. Water is the basis of life, it supports life, and countless species live in it for all or part of their lives. Freshwater biomes supply us with our drinking water and water for crop irrigation. The world’s oceans have a great effect on global climate as water has a high capacity for heat, and because the Earth is mostly covered with water, the temperature of the atmosphere is kept fairly constant and able to support life. The oceans contain several billion photosynthetic plankton which account for most of the photosynthesis occurring on Earth. Without these, there might not be enough oxygen to support such a large world population and complex animal life.!
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The climate and temperature of the aquatic biome is extremely diverse, the climates varying in different regions. With ponds and lakes, temperature varies seasonally. During the summer, the temperature can range from 4° C near the bottom of the body of water to 22° C at the surface.
During the winter, the temperature at the bottom can be 4° C while the top is 0° C. In between the two layers, there is a narrow zone called the thermocline where the temperature of the water changes rapidly. During the spring and autumn, there is a mixing of the top and bottom layers, usually due to winds, which results in a uniform water temperature of around 4° C. The deep ocean is called the abyssal zone, the water in this region is very