Aug. 31 (UPI) — Hundreds of thousands of dead fish are polluting waters in Volos, Greece, and creating a public health hazard that caused authorities to declare a civil protection emergency for one month.

Volos is located in Thessaly about 250 miles north of Athens, and local authorities are removing 100 tons of the dead fish every day and taking them to an incinerator for disposal.

The civil emergency expires on Sept. 30, but local officials expect to finish the cleanup of dead fish as soon as Sunday.

Heavy rains from Cyclone Daniel last September caused local reservoirs to flood and breach levies, and dams flushed the freshwater fish into drainage ditches, which enabled them to thrive throughout the winter.

Springtime irrigation for nearby agricultural fields drained the ditches and forced the freshwater fish into the nearby Pagasetic Gulf, which is a saltwater body on Greece’s eastern coast.

Exposure to the saltwater killed the fish, whose bodies contaminated local beaches and bodies of water.

Petros Varelidis, secretary-general for Natural Environment and Waters, said many fish died when the flooded Karla Lake in Thessaly in central Greece enabled more fish to spawn.

When the lake slowly returned to its normal size, the excess fish slowly suffocated and died.