Armenia’s largest freshwater lake blooms once again
Lake Sevan, high-altitude freshwater lake, has once again bloomed in Armenia. This phenomenon has been observed annually for several years.
Ecologists name several reasons for the blue-green algae bloom, including high temperatures and a decrease in the water level, which disrupts the balance of the lake’s ecosystem. Experts also talk about the presence of organic matter in water.
The problem is that this situation can ultimately lead to Sevan becoming a bog.
What is happening in Lake Sevan?
The bloom was somewhat delayed this year—it started in mid-June and will continue until almost the end of August, says Gayane Shahnazaryan, deputy director of the Hydrometeorological and Environmental Monitoring Center.
She says that the color intensity has remained practically unchanged over the past three years.
Shahnazaryan believes that the lake blooms due to a decrease in the water level, which disrupts the balance of the Sevan’s ecosystem.
Director of the Scientific Center of Zoology and Hydroecology Bardukh Gabrielyan says that the high temperature and the presence of organic substances in the water are to blame:
“It’s no secret that the bloom became visible precisely after a constant decrease in the water level for several years in a row…The problem in this case is aggravated by the fact that algae do not disappear, but sink to the bottom, becoming an additional source of organic matter accumulation and flowering in the lake during the next year.
In his opinion, it is difficult to fight against this phenomenon, but the situation can be improved by raising the water level:
“We also need to work to reduce the volume of organic matter by installing treatment plants. In addition, it is important to achieve a balance in the number of fish in the lake, which will eat the food, since when it accumulates on the bottom of the lake, it also eventually becomes a source of organic matter. Now we are working to artificially combat this phenomenon by using methods to absorb these organic substances without harmful consequences for the environment.”
What they say in the Ministry of Environment
On July 22, Voskehat Grigoryan, a representative of the Ministry of Environment, spoke about the work to restore the ecological situation around Lake Sevan, as well as measures to clean up the coastal areas. This refers primarily to flooded forests.
A program to clean up the area was developed and put into action last year. It will continue into next year. In total, approximately 750 hectares of areas around the lake need to be cleaned up. In 2020, they plan to clear 271 hectares, “of which 50 hectares have already been cleared.”
The ministry also promises to resolve the issue of waste from sewers.
“In three large polluting cities: Gavar, Martuni and Sevan, we plan to create biological treatment plans next to the mechanical ones,” said Voskeat Grigoryan.
They will be built as part of a project funded by the European Union. The EU has provided Armenia with a grant of 5 million euros to solve the problems involving the lake.
The Sevan problem
Ecologists and public organizations have been raising awareness about the Lake Sevan blooms for several years already.
In the summer of 2018, when Lake Sevan bloomed, environmentalists talked about the dangers of swimming in the lake.
Director of the Sevan National Park Vahe Gulanyan then publicly drank a glass of water from the lake in order to prove that Sevan water is safe. The Armenian media reported that he was later hospitalized.
In 2019, the Ministry of Health issued a statement on the dangers of swimming in the lake.
In response to this, the owners of cafes and restaurants near the lake staged a protest swim in order to prove that swimming in Sevan is safe.
Every year, different officials promise that the water level of the lake will be raised and that all the issues of the Sevan ecosystem will be resolved.