Greece: Oxygen-starved fish dying in drought-hit lake

NASA Space and Science

Dead fish lie on the shores of Koroneia Lake in northern Greece, on Thursday, Sept. 19, 2019. Tens of thousands of dead fish are washing up as the water level has plummeted to less than a meter deep (three feet) and the lack of oxygen in the water is leading to mass mortality of everything in it. (AP Photo/Giannis Papanikos)

This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

KORONEIA, Greece (AP) — Tens of thousands of dead fish have been found on the banks of a lake in a protected nature reserve in northern Greece after high temperatures and drought conditions caused a severe drop in water levels.

State environmental officials said Thursday that the water level at Lake Koroneia has dropped by more than 70% percent in the past three years, to 80 centimeters (31 inches), with the decline triggering the death of carp, sunfish, bleak and other freshwater fish.

Dimitra Bobori, an associate biology professor at the University of Thessaloniki and the lake’s senior administrator, said dissolved oxygen concentrations in the water had fallen below a critical level, accelerating the deaths over the last week.

“Due to the high temperatures, the solubility of oxygen is limited in the body of water that is left,” Bobori said. “We have sent samples of dead fish and water for toxicological testing, as high temperatures also give rise to toxicity levels.”

Once one of Greece’s largest lakes, Koroneia is 30 kilometers (18.5 miles) east of Greece’s second-largest city Thessaloniki.

Originally spanning 4,500 hectares (11,000 acres), it has shrunk to about a third of its original size over the past three decades.

The lake is part of the European Union’s network of protected nature areas and Greek authorities have launched a long-term effort to try and prevent Koroneia from drying out, employing water diversions, temporary fishing bans, and a crackdown on the illegal disposal of industrial waste from nearby factories.

Water levels had stabilized at about three meters (10 feet) by 2015, but summers are getting longer and hotter.

“Over the last 20 years, there is no doubt that the weather has become hotter in this region, and the trend is worsening,” Prodromos Zanis, a professor of meteorology and climate science at the University of Thessaloniki, told The Associated Press.

“The frequency of this phenomenon makes it statistically likely that this is in part driven by manmade climate change.”

Villages on the banks of Koroneia and nearby Lake Volvi have seen their livelihoods hit by the receding water.

“There are thousands of dead fish near us and the smell is awful,” said store owner Nikolaos Rossias, from the lakeside village of Agios Vassilis. “There used to be 10 fish restaurants in the village.”

Now there is only one.

“It feels like nobody cares about the lake … so many fish have died and our wealth was destroyed.”


Follow Kantouris at

Copyright 2020 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

CBS47 On Your Side

Do you have a problem that you need help solving? Contact CBS47 and let us be On Your Side.

Phone: 559-761-0383

Don’t Miss

Sunday Service
Best of the Valley
Sunday Morning Matters
MedWatch Today
Hispanic Heritage
Bulldog Insider: The Podcast
The Valley's Armenia
Pros Who Know

Images from Armenia

Small patients in Armenia
Yerevan by night.
Dr. Jeff Thomas delivers.
Dr. Jeff Thomas delivers in Gyumri.
Doctors unpack medical supplies from The Central Valley.
Fresno Medical Mission at work.
Medical Supplies being unloaded.
Fresno Medical Mission at the ready.
KSEE24 crew witnesses the miracle of life in Gyumri, Armenia.
Life saving work of Central Valley surgeons in Armenia.
Ribbon cutting on new surgical center in Ashtarak Armenia. Fresno donors made this dream come true.
KSEE24 on assignment with the Fresno Medical Mission
Honorary Consulate to Armenia Berj Apkarian explains the crisis facing one hospital.
KSEE24's Stefani Booroojian and Kevin Mahan at the meeting with President Bako Sahakyan.
Medical Meeting in Artsakh.
The President of Artsakh meets with the Fresno Medical Mission.
Learning modern medicine techniques with the Fresno Medical Mission in surgery.
Leaning in for a look. Dr. Brien Tonkinson holds class and helps a patient in Armenia.
Fresno Medical Mission cares on one of the smallest patients in the region. Six-year old Yanna receives life-changing better breathing surgery.