Emission of ultrasonic waves, placement of other organisms that eat them, throwing clay into the waters and placing monitoring buoys.
These are some of the methods that the government is carrying out or evaluating to apply to combat cyanobacteria.
And it is that these algae, in addition to being a headache for the tourist season, are a risk to human health and fauna.
The forecast is that this summer they will appear in the Río Negro, the Río Uruguay and on the coasts of Colonia and Montevideo.
Whether they reach the eastern beaches will depend in part on the rain and the dynamics of the water.
The amount of cyanobacteria in Uruguayan waters "is increasing every year."
They are "ancient organs -in part, those that gave rise to life- and have a genetic adaptation of hundreds of thousands of years".
Faced with an "increase in nutrients, they quickly respond and come to dominate the environment";
and after they are in the water, they are "difficult" to control, explained the researcher from the Faculty of Sciences and the Eastern Regional University Center of the University of the Republic, Carla Kruk.
The government is carrying out several mechanisms trying to curb cyanobacteria, said Environment Undersecretary Gerardo Amarilla.
It must be taken into account that the following measures act on the microorganisms and not on the causes, that is, they are not preventive.
However, control measures are being carried out in parallel and work is being done on other improvements.
One of the mechanisms are buoys that emit radiofrequency waves in the water and work with solar energy.
They prevent these microorganisms from rising to the top, where the sun is, to carry out photosynthesis.
The white hierarch said that it is being tested in two different places, but that the technicians raise the question of how much it can affect the reproduction of other organisms, something that is under study.
Control is also carried out through satellite images that allow them to know six or seven days before if there are going to be cyanobacteria, he added.
Another method used is to throw Phoslock into the water with cyanobacteria, a modified clay that absorbs the phosphorus on which these microorganisms feed.
One of the systems that is being evaluated, which Amarilla proposed to OSE, is the injection of ozone and oxygen into the water, to eliminate the conditions for their reproduction.
Placing certain bacteria to fight them is also being studied.
For his part, Kruk warned that "biomanipulation is a very sensitive issue."
Kruk explained that methods such as Phoslock and radiofrequency waves are "applicable to small environments" and cannot be used in large areas.
The researcher pointed out that, for example, with clay one cannot "cover the bottom of the Río de la Plata."
In addition, since the "input of phosphorus is continuous, it would be necessary to put more and more material into the water all the time, which is unfeasible both in quantity and cost," she added.
For this reason, he understands that the "fundamental management that should be done is the reduction of nutrients that reach the river."
The forecast is that cyanobacteria will "be on the coasts of the Negro River and the Uruguay River, as has happened since 2000" There will also be on the coast of Colonia "quite frequently", since it is a "sweet environment where they are more intense", explained Kruk
In the capital "there will be but with less frequency", and it will depend on the amount of rain, which drags the cyanobacteria. And, if the rainfall is "important", they will carry these microorganisms to the eastern coast. "There will probably be Playa Verde or Piriápolis," he added.
The main cause of cyanobacteria is the agrochemicals -such as fertilizers- that are used in the soil.
The rain makes the substances reach the waters and these microorganisms use them to increase their quantities.
"Companies like UPM that are on the coasts and release nutrients or chemicals" also contribute to the formation of blooms;
and reservoirs, he said.
tourism during the summer.
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