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Freshwater Biome

Freshwater biomes are simple all the salt-free (not like the salty seas) water that flow or exist inland. They are extremely useful in many ways as they provide humans and animals with drinking water. They also make irrigation, sanitation and other water activities possible. Fresh water biomes are divided in three main categories: lakes and ponds, rivers and streams, and wetlands.

A. Lakes and ponds

Lakes and ponds come in various sizes and depths, and may be found all over the world. Ponds tend to be smaller and seasonal. They have less diversity because they exist in isolation and are smaller in size. They have a photic layer too, where there is sunlight at the upper layer of the water, making photosynthesis possible. Most living activities that depend on sunlight and temperature occur at the upper layers. Phytoplankton such as algae is very common in this layer, together with smaller insects and creatures such as the crustacean, amphibians, fishes and insects. Life forms in this part of the water form the base of the food web. Deeper down, the temperature is cooler and has very little or no light with dead organisms settled there. Lakes and ponds have seasonal temperatures, where is it usually very cold or frozen at the surface (and about 4oC at the bottom) during the winter. In the warmer seasons, the surface temperatures rise to about 22oC, whiles maintaining the bottom zone cold temperatures.


B. Streams and rivers

This is flowing water that begin usually with melting snow, rain or other watersheds. They flow quicker at the head and slower as they enter the seas at the estuaries. Abiotic factors such as temperature, light, flow and pressure are usually different at both ends of these flowing waters. Rivers could be short and small, or very large and long. The Nile in Africa and Amazon in South America are good examples of long and large rivers. From the head, the temperatures are cooler, has more light, is fast-flowing, has lower nutrients and generally clearer. As a result, there is less phytoplankton, but rather more rocky-based algae. Animals in these waters are well adapted to its fast flowing nature. Trouts and leeches do well here. At the ends of these streams and rivers, the water is murky from all the continuous mixing of sediments and dissolving of substances. It is warmer because the waters are wider now and are exposed to sun’s energy. They are slow-flowing. Here, worms and insects are common, together with fish like the catfish, carp and frog types.


C. Wetlands

Wetlands biome

These are water bodies that are still, stagnant and ‘just there’, usually as a result of saturated soils or land beneath. They often have vegetation that has their roots in the soils but leaves and flowers above the water surface (emergent vegetation). Examples include black spruce, tamarack, cattails and pond lilies. Wetlands include marches and swamps. Some wetlands have very high salt content and may not be classified as freshwater. These biomes, especially bogs, are characterized by standing water, have a lower pH, and are lower in oxygen and nitrogen.

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