Tiberias police on Sunday detained a 30-year-old resident of the city on suspicion of carrying out mass poisoning of fish in the Kinneret.
On Saturday, the Health and Agriculture Ministries warned the public against purchasing fish from the Tiberias marina or from unknown sources after tens of thousands of dead fish washed up on the Lake Kinneret shore near the marina in the early morning.
The Agriculture Ministry was expected to announce whether the cause of death was definitely poisoning, and what substance was in use.
Late Saturday, two soldiers were admitted to the Nahariya Hospital for abdominal pains. They said they had spent the weekend by the Kinneret and eaten fish they found floating near the shore, which as was later revealed, had been poisoned. They were released Sunday morning when their condition improved.
The Health Ministry said on Saturday that only the Tiberias marina area had been affected and that fish from other parts of the Kinneret are safe for consumption.
"Following initial reports of dead fish around the marina, our inspectors were deployed around the Kinneret to make sure there are no other affected sites," said Health Ministry Public Health Director Ze'ev Fisch.
"It was a difficult sight, there was a virtual carpet of tens of thousands of dead fish floating on the surface of the water," the head of the supervisory division of the Kinneret Administration, Yehuda Nitzani, said Saturday.
Teams of Health and Agriculture Ministries on Saturday inspected the city's markets, as well as the Nazareth market where a few poisoned fish were found.
Fish in Lake Kinneret have been poisoned a number of times in recent years. Even a tiny amount of poison can kill large numbers of fish, saving the perpetrators from the labor of catching the fish with the usual methods. On previous occasions where poisoning was suspected no warning was issued to the public.
Some observers believe the poisoning is far more widespread than is generally believed and is one of the main reasons for the decline of fish stocks in the lake in recent years.