“All our achievements in Lake Sevan have been last because of the water outlets and drastic changes in weather. The lake is again in an unstable situation,” Director of Institute of Hydroecology and Ichthyology of RA NAS Evelina Ghukasyan told EcoLur.
Reminder: this year almost the entire mirror of Lake Sevan bloomed with green algae because of the additional water outlets and high temperature, the lake transparency decreased from 14 meters up to 2 meters, a temperature higher than the standard was recorded in the lake, waterlogging processes have been active in the lake.
In reply to EcoLur’s question what the current state of the lake is, Evelina Ghukasyan said, “Currently our research has shown there is a lack of oxygen under the depths over 30 meters. It is not that favorable for bottom animals, especially for the existence of creatures needing oxygen. In this case, crawfish is considered to be such a creature. The trout and the whitefish move more actively and there is no serious threat for them, as they can move from the areas with low oxygen to the areas with high oxygen. Blooming has stopped long ago, decomposition phenomena will also stop, as there is an active circulation of water in the fall months, as a result of which all the layers of water get rich in oxygen. So far no negative phenomenon is being observed, water transparency has increased and leveled to 7-8 meters, no drastic increase in the phytoplankton is planned.”
Evelina Ghukasyan noted that we should be very cautious in case the climate changes, “If the temperature rise is repeated next year, we will, unfortunately, have more serious consequences. Again water blooming, deterioration of the water quality, a drastic increase in toxic algae: all these are not desirable not only in environmental terms but also in recreational terms,” Evelina Ghukasyan said.
Speaking about the fish reserves of Lake Sevan, the scientist noted that still there are no industrial reserves in the lake: mainly the reserves of the whitefish have increased, while the reserves of typical carps have drastically reduced because of the diseases in the lake. “The situation with the crawfish is very serious, as there are diseases spread among the crawfish, besides, the reserves have drastically reduced because of hunting with illegal hunting tools as compared with the reserves we had last year. Very soon we may have a very serious problem with the crawfish reserves.”
Speaking about the trout development in Lake Sevan in cage nets, Evelina Ghukasyan said local pollution has been recorded which is not that visible at 100-200 meters. Nevertheless, in case the development scales expand, the local pollution may get expanded.
11:54 October 31, 2018