Experts said the problem was caused by historic floods last year that inundated Thessaly plane farther north. The floods refilled a nearby lake that had been drained in 1962 in a bid to fight malaria, swelling it to three times its normal size.
Since then the lake waters have receded drastically, forcing the freshwater fish toward the Volos port that empties into the Pagasetic Gulf and the Aegean Sea, where they cannot survive.
Note: I'm not sure I understand the reason why this happened or how the net would have >A net was not placed at the mouth of the river leading into Volos, the experts said. When the fish met the sea, the saltwater likely killed them.
Note: I'm not too sure how the suggested net would have protected the fish. Wouldn't they be caught in it and crashed by other fish?