Why is Lake Sevan turning green and what steps are being taken to solve the problem? The Ministry of Environment released a clarification about this, as the press release of the Ministry informs about this”
“Dear citizens,
The problem of the activation of blue-green algae in Lake Sevan is in the focus of the professional units of the Ministry of Environment. Blooming of algae (also cyanobacteria) in Lake Sevan is mainly caused by the following factors:
- a large amount of phosphorus and nitrogen compounds, which serve as nutrients,
- high water temperature,
- fairly high intensity of light,
- reduction of the hypolimnium layer in Little Sevan and its elimination in Large Sevan as a result of lowering the lake level.
As a result of the reduction and absence of the hypolimnium layer, there is an intense transition of phosphorus from the bottom layer to the water layer.
Phosphorus concentration in Lake Sevan continues to increase, because the lake is overloaded with biological substances brought by waste water caused by human activity.
At the moment, Lake Sevan is in the intensive blooming stage, according to the trophic state, the lake corresponds to the mesotrophic state.
As a result of intensive blooming of the lake, the concentration of phosphate decreases. Compared to June, the concentration of phosphate ion decreased by almost 2 times on July 15. The assimilation of phosphorus by the biomass proceeds intensively, and when the concentration of phosphorus in the water is almost equal to zero, the process will end. According to observations, the process will last 2-3 weeks.
July 19, 2022 at 15:09