Becoming Extinct Elsewhere, Sandbar Sharks Find Sanctuary off Israel’s Coast

It’s not because Israelis are – for the time being – prohibited from bathing in the Mediterranean to prevent them from being too close to each other. While sharks are going extinct in the Mediterranean Sea, sandbar sharks – one of some 400 shark species in the world’s waters – are flourishing. 

This body of water has become an “oasis” for this type of sharks, which have been spotted off Ashdod port and off the coast of Hadera (some 45 kilometers north of Tel Aviv) by researchers at the Morris Khan Marine Research Station of the University of Haifa’s Leon Charney

School of Marine Sciences. One reason for this is apparently the warm water produced as a by-product of the power plant at Hadera 45 kilometers north of Tel Aviv. 

In fact, the sandbar shark (Carcharhinus plumbeus) is a species of requiem shark and part of the family Carcharhinidae, native to the Atlantic Ocean and the Indo-Pacific and not to the Middle East. It is distinguishable by its very high first dorsal fin and interdorsal ridge.

The university’s marine biologists have established long-term marine ecological research stations to focus on the sharks and other species in the waters.

Sandbar Sharks photos courtesy of Dr Aviad Sheinin

Commonly found over muddy or sandy bottoms in shallow coastal waters such as bays, estuaries, harbors or the mouths of rivers, the shark also swims in deeper waters and in intertidal zones. Sandbar sharks are found in the western Atlantic from Massachusetts and the Florida Keys to Brazil and Turkey.

The sandbar shark, also called the thick skin shark or brown shark, is one of the world’s largest coastal sharks. It prominent dorsal fin is triangular and very high, and it has very long pectoral fins. The huge fish usually have heavy-set bodies and rounded snouts that are shorter than the average shark’s snout. Its upper teeth have broadly uneven cusps with sharp edges. Its second dorsal fin and anal fin are close to the same height. With a body color that ranges from a bluish to a brownish grey to a bronze, with a white or pale underside, sandbar sharks swim alone or gather in sex-segregated schools that vary in size.

Because of their high fin-to-body weight ratio, the species have decreased in number due to overfishing, especially in the US. Even though they are large and have sharp teeth, they are considered not to be dangerous to humans and they usually don’t feed on the type of fish that are raised in aquariums.

It turns out that the waters west of Israel are very comfortable and friendly to sandbar sharks, said Dr. Aviad Sheinin, director of predatory species at the university’s marine research station. 

Over the past five years, the station’s researchers have spent their time investigating the unique phenomenon of why sandbar sharks have been attracted to Hadera and Ashdod. “We were delighted to see dozens of the sharks, even though they are an endangered species in the Mediterranean. It was so exciting to see such a large group here,” Sheinin continued. 

Marine research was halted in the past two months due to the COVID-19 pandemic, crisis – and the restrictions are still in effect.  As a result, University of Haifa marine biologists were unable to implement most of their plans and Ashdod sharks for the first time. However, they did manage to set up a system to detect whether sharks tagged acoustically that reached Hadera for the warm waters also swam southward to Ashdod. 

“Israel stands out prominently in passing legislation that prohibits fishing of sharks and “sea cats” (a type of octopus) and has made them protected species,” concluded Sheinin. “It is important to remember that they should not be harmed or interfered with in their habitat. We hope that we will continue to witness the phenomenon of a large number of sharks on Israel’s shores, and this is what our study will look at in the coming years. “Sharks are predators in the marine ecosystem, and understanding their distribution patterns and behavior is essential to understanding our entire system.”

 

 

 

Source: Israel in the News