Armenian environmentalists are warning that the country's largest lake is facing a serious threat from algae and falling water levels.
They told reporters that unless the authorities take action "the lake will turn into a swamp" through waterlogging, the Aysor news site reports.
The group is led by Karine Danielyan, a veteran ecologist and head of the Environmental Committee of the government's advisory Public Committee.
It was the government's publication of satellite images of the algae earlier this month that prompted public concern.
'Gone in a fortnight'
Environment Minister Erik Grigoryan tried to put the algae bloom in the broader context of climate change, noting similar phenomena in Russia's Lake Baikal and the Black Sea.
He said it would "be gone within a fortnight", but campaigners insist that specific local factors are at play in Armenia.
Sevan also saw an algae bloom last year, prompting the health ministry to advise swimmers against venturing into the lake, and Mr Grigoryan recalled an algae scare back in 1964, but this year's satellite images show almost half of the lake coloured green.
Water resources analyst Knarik Hovhannisyan puts the blame firmly on drawing too much water for agriculture irrigation, which has led water levels to fall on four registered occasions since 2012 when they should have risen.
She also told Radio Liberty's Armenian Service that pollution from booming tourism resorts on the shore, as well as dumping wastewater into tributary rivers, "could mean losing the only freshwater basin in the region".
The immediate measures she proposes are installing modern wastewater treatment plants at lakeside hotels and restaurants, as has been a legal requirement since 2006, and carefully monitoring water levels. "I am sure that the 170 million cubic metres (37,395 million gallons) of water flowing into the lake annually is now an over-estimate, given global warming," she told Radio Liberty.
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Mr Grigoryan assured the public that a tender is under way to clean up the shore and rivers, so that "by 2020-2021 this whole area will be completely clean" and water levels should rise again.
Water Committee Chairman Vardan Melkonyan also told reporters that significantly less water has been drawn from Sevan so far this year - 29 million cubic metres (6,380 million gallons) - than the 43.5 million in the same period of 2018.
But campaigners still doubt the government's sense of urgency.
"We warned them about this two months ago. All the measures may be in place, but we are still destroying Lake Sevan through our thoughtless actions," Karine Danielyan told Aysor.
Reporting by Martin Morgan
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