Drought, management shortcomings and extreme water consumption, might be responsible for the recent death of thousands of fish in Lake Koroneia, located at the heart of Thessaloniki regional unit, in Central Macedonia, Greece.
Carp and butterflyfish washed up on the banks a few days ago, and water is now reaching only 60 to 80 centimeters high, despite this, there are still miraculously hundreds of fish present in the lake.
A sample of these fish was sent recently to regional veterinary services for laboratory analysis, at the request of the Koroneia-Volvi-Halkidiki Lake Management Organization.
“There’s still life in the lake, and although in poor ecological condition, it is able to support nine species of fish,” Elias Tekidis, Coordinator at the Koroneia-Volvi-Halkidiki Lake Management Organization told Greek state-run AMNA news agency on Saturday.
“However,” he continued, “the lake’s ecological status remains consistently poor, even after 2015, when technical works were carried out, and there was substantial rainfall which increased the amount of water and led to higher numbers of fish and poultry.”
Despite the minor improvement of 2015, Tekidis said, “the problem has not been solved and the lake’s ecological status is far from what it should be, it has simply been marginally better than in previous years.”
An important factor affecting the amount of water in lake Koroneia, according to Tekidis, is the so-called aquatic balance, which is currently negative, especially after reduced rainfall, increased water consumption in the area, and some 1,500 local drillings for irrigation purposes.
This is gradually causing further negative reactions to an already bad ecological status, as microorganisms are increasing, and conductivity is reduced.
This affects the concentration of ions in the water, and oxygen is depleted, therefore, it only makes sense to foresee a mass extinction of lake species soon,” urged Tekidis.
Asked how the situation at Koroneia can be reversed, Tekidis said that ”there is a lack of adequate coordination in central government and perhaps at ministry level; this is why decisions cannot be reached at a faster pace, both on the operation of rescue projects and on the management policies that need to be adopted.”
In response to Lake Koroneia’s urgent situation, Constantin Aravossis, Secretary-General for Natural Environment and Water at the Greek Ministry of Environment and Energy, and in cooperation with the Ministry of Macedonia & Thrace, has called for a broad meeting of officials from relevant ministries, local authorities and scientific bodies on October 1, in order to seek immediate action, to perhaps restore the lake to its former natural state.