Seasonal fish mortality draws sharks to central beach, alarming bathers

Scientists are unable to fully explain why a number of sharks approached the beach at Beit Yanai in central Israel last week, apparently for the first time.

The animals prompted some bathers to scurry for dry land and drew intense media interest.

The harmless dusky sharks were spotted Thursday close to the point where the Alexander River meets the Mediterranean Sea.

According to Channel 12 news, a lifeguard told bathers to get out of the water, and panic erupted. The site quoted one beachgoer as saying, “I’m sitting on the beach, just opening my beer. Suddenly I see a fin sticking out, 10 meters (yards) from the shore. People here started gathering and taking pictures. [Others] were scared.”

Aviad Sheinin, head of the Apex Predators Lab at the University of Haifa, told The Times of Israel on Sunday that similar shark sightings are common in April, when extreme heat events warm up the water, but are usually located around the Orot Rabin Power Station, some seven kilometers northeast of Bet Yanai, and near the Rutenberg Power Station, close to the Gaza border.

Dusky and sandbar sharks have been frequenting the warm waters of the two power stations between November and May for many years, Sheinin said.

Sudden heat events typical of the season are known to cause mass fish die-offs in the streams that drain into the sea. The warmer the water, the less oxygen the fish have to breathe. The dead fish are washed down to the shallow waters of the sea, where they draw the sharks who are able to freely dine.

In the past week, both the Hadera and Alexander streams have seen such mass deaths.

“Unless there are more fish die-offs, the shark visits to Beit Yanai are probably behind us,” he said.

Sheinin added, “The role of the sharks is to remove sick, wounded and dead fish from the sea. They help keep the sea fertile and clean.”

Dead fish in the Hadera stream in central Israel, April 20, 2025. (Aviad Sheinin)

Yair Suari, a water chemist and physicist who studies estuaries and works at the Ruppin Academic Center’s Marine Sciences Faculty in Michmoret, a short drive from Orot Rabin Power Station, said there had been four mass fish die-offs over the past 15 years in the Alexander River.

Sewage flow from the Arab town of Qalansawe had probably contributed to last week’s die-off, he said, although to the best of his knowledge, this was the first time sharks had come.

“Why did they only come this year? It’s a good question,” he said.

Sheinin cited University of Haifa research showing that dusky and sandbar sharks visit the power stations to warm up from November to May, spending alternate periods of three to five days at the stations and and in the open sea looking for food. From June to October, they wander around the Mediterranean, reaching Egypt, Cyprus, and even Italy.

He stressed that these sharks, which can reach lengths of up to four meters (12 feet) in the case of dusky sharks, and 2.4 meters (eight feet) for sandbars, do not attack humans, but as protected species, should not be approached. He advised line fishermen to drop their fish if they spot them, so as not to create friction with the sharks.

According to Sheinin, there is no evidence of warming seas attracting more dangerous sharks to Israel’s coasts.