Why in no case should you swim in ponds with an excess of algae

Residents of the United States announced the death of their dogs, which occurred after bathing their pets in water bodies abundant in blue-green algae. Experts associate unpleasant events with these microorganisms, which are found in abundance throughout the planet, both in fresh and in salt bodies of water. But how harmless algae could kill dogs, and is this swimming dangerous for humans?

To begin with, blue-green algae are actually neither algae nor plants. Under this name are cyanobacteria - living microorganisms, that is, representatives of the animal kingdom. Why is their second name a blue-green algae that is misleading? The fact is that these unique microorganisms have the ability to photosynthesis, so they are classified as phytoplankton and have such a second name. More precisely, this is their first name, since scientists for a long time considered them to be algae, although it was later proved that from a biological point of view these are bacteria. But we omit the subtleties of terminology and consider these organisms in more detail.

Cyanobacteria are very unpretentious to the habitat, so their range is very extensive. In addition, their diversity is also great - this department of bacteria has more than 400 species. Cyanobacteria are found in abundance in the seas, fresh and salt lakes, as well as in slowly flowing small rivers and swamps. Under favorable conditions, such as high temperatures and an abundance of phosphates dissolved in water, a sharp increase in the number of cyanobacteria is observed. Most often, water in such cases changes its color to saturated green, so the process is called "algal bloom". This phenomenon can be observed both in warm lakes in southern Russia and in the rather cool Barents Sea, which warms up at the end of summer to temperatures optimal for bacteria.

What happens with a sharp increase in the number of bacteria in water? Instead of producing oxygen, a large number of bacteria begins to consume it. Oxygen is consumed both for vital activity and for the decomposition of dead microorganisms, whose lifespan does not exceed 12 hours. As a result, the content of oxygen dissolved in water decreases, which negatively affects the life of the inhabitants of the reservoir, up to the death of fish.

But excessive oxygen uptake is not the only problem caused by cyanobacteria. These microorganisms produce neurotoxins, which at significant concentrations can worsen people's health and even lead to death if water is swallowed. Therefore, swimming in water bodies, where a characteristic color for cyanobacteria is abundant, is not possible. The same applies to bathing animals that are also defenseless against the effects of neurotoxins.

Environmentalists predict that in the near future, cases of mass flowering of water bodies will be recorded more often. This is primarily due to a general increase in temperature on the planet, as well as a high level of pollution of water bodies. Phosphates, along with nitrates, pesticides and petroleum products, are the main pollutants in fresh and marine waters on our planet. There is no doubt that the intensive development of agriculture and the growth of the Earth's population will lead to a further increase in the level of phosphates in the water of lakes and rivers. It only remains to be reminded that one must be extremely careful when going on vacation to a lake or river so as not to become a victim of treacherous blue-green algae.