Hydrofauna of reservoirs is divided into two large groups - singlecell and multicell organisms. These groups cover the various representatives from primitive ones up to well organised fishes
As a result of photosynthesis the concentration of the oxygen, dissolved of water, grows and the contents of free carbonic acid in it is reduced. Despite of some positive role of water plants as biological factor, as a whole they have the negative effect, as this leads to the reduction of useful capacity of a water source, the decomposition of bioweight of plants results in hit of organic substances in water, its secondary pollution.
Microfits are the seaweeds playing a huge role at the water life. Chlorofill is present in them and it helps photosynthesis. They are subdivided in green, bluegreen etc. The green seaweed having bright - green colouring, develops usually in the beginning of the summer; bluegreen, containing a dark blue pigment - mainly in the second half of summer. Bluegreen seaweeds are unique, consuming three gases, dissolved of water, - nitrogen (including ammonia), carbonic acid and oxygen, and during photosynthesis they, as well as all other seaweed, allocate oxygen. The photosynthesis proceeds at the presence of light, carbonic acid favourable temperature, organic and inorganic combinations necessary for an exchange of substances of the cells of seaweed.
