Many of us had to watch the picture when the once beautiful pond, stakes or lake turns into green ugly dregs. What is happening with these water bodies and what can help them preserve their ecosystem?
What ruins the aquatic environment
Scientifically, this harmful phenomenon is called eutrophication. This word literally means “abundant nutrition”, that is, the reservoir is filled with nitrogen and phosphorus, which, in turn, provokes the “blooming” of water and impairs its quality. Such an excess of these nutrients also contributes to the excessive appearance of anaerobic microorganisms. All this leads to a decrease in oxygen in the water, because of which begins the mass death of fish. Also, because of the overgrown algae, the rest of the plants in the ponds do not receive enough sun, resulting in depleted flora.
Causes of pollution
Often, eutrophication is just a natural process of lake aging. For hundreds of years, sludge has constantly settled to the bottom, from which the bowl ceases to be deep-sea. Therefore, once a clean pond turns into stagnant muddy waters unsuitable for fish. There is also such a thing as combined eutrophication. In this case, the process of “desolation” is facilitated by many factors, such as fallen leaves, fallen trees, sewage, trash of passers-by and tourists. But these are not the only sources of water pollution. Many waters suffer solely from human activities. Nature “stretched” these stagnant processes for thousands of years, but people were able to speed them up and ruin them in just a few decades. The reason for this is the abundant emissions of ammonia and nitrogen oxides.
Effects
The reasons for the eutrophication of water bodies mentioned above lead to the fact that biogens begin to appear intensively in the aquatic environment. They contribute to the following processes:
- Living organisms in the water begin to die and fall to the bottom. Due to perceptible decomposition, oxygen practically disappears at a depth. Because of this, the rest of the fish also die, which launches a new chain, it decomposes, oxygen disappears and eutrophication intensifies. This, in turn, launches an almost irreversible process.
- Water becomes dark due to the appearance of a huge number of plankton. For this reason, light is not able to break through to the bottom, as a result of which useful plants of water bodies disappear at a depth. Without underwater flora, oxygen cannot form.
- In the summer, the situation becomes more complicated due to biogens, because cold water flowing at the bottom and hot water from above cannot mix, therefore, the eutrophication of water bodies increases.
- With the onset of the evening, a large amount of plankton begins to absorb oxygen residues, by morning exhausting the reservoir, the fish remains without air. This entails her death.
- If the reservoir served as a source of water for the population, over time it may become unusable. This happens due to the fact that anaerobic processes contribute to the appearance of toxic elements in the water, such as methane and hydrogen sulfide.
Signs of pollution
Eutrophication of water bodies is determined by external characteristics. The liquid exudes a characteristic “heavy” aroma, and a plaque appears on its surface. You can also notice the abundant appearance of tina, “islands” of algae with duckweed. This green stains water in an appropriate shade. A thick, viscous and unpleasant mass of organic deposits appears at the bottom. If this process is left to chance, the pond will soon grind and become a swamp.
Marine environment and nitrogen
Unfortunately, some seas are also prone to disastrous effects. Basically, nitrogen gets into these waters from nearby lands on which it settles. Surface water flushes this element from the soil and carries it to the sea. A warm climate usually prevails in these areas, and this provokes the early decomposition of organic products.
Recovery ability
It is known that eutrophication is not an irrevocable process. He is able to stop, and gradually the reservoir restores its original ecosystem. This applies not only to those cases when the process of desolation is still at the very beginning. Even with prolonged “infection”, water bodies can independently “cure themselves”. But there is an important condition for this. The ecosystem resumes if nitrogen leakage is eliminated or minimized. There have been cases of recovery when the pond has been saturated with nitrogen for a very long time. When this source was removed, a large amount of accumulated substance remained in the soil. But the vegetation served as an impenetrable carpet, which did not adversely affect the aquatic ecosystem. The lake was really being restored. Unfortunately, deforestation or quarrying began near rivers and ponds, and this “protective” layer, which protected the liquid from nitrogen, was disturbed, and the eutrophication process resumed.
