Great white shark jumps from sea into research boat

Marine researchers in South Africa had a narrow escape after a three-meter-long great white shark breached the surface of the sea and leaped into their boat, becoming trapped on deck for more than an hour.

The incident occurred while the
research team was conducting a shark population dynamics study that has been ongoing for the past three years off Seal Island, near Mossel Bay, on South Africa's Cape coast. (Right: map courtesy of Ocean's Research)

They had been chumming for over an hour using sardines as bait to attract the predators. The seven-strong crew had a fair amount of activity around the boat and were able to observe four great whites. The animals are renowned locally for bursting through the surface as they prey on seals.

Dorien Schröder, team leader at Oceans Research, based at Mossel Bay,
said that last Monday morning, after more than an hour of shark activity around the vessel, the Cheetah, the waters at the stern had been quiet for five minutes. "Next thing I know I hear a splash, and see a white shark breach out of the water from [the] side of the boat hovering, literally, over the crew member who was chumming [throwing food bait] on the port side," she said.

Schröder recounted how she pulled her colleague to safety before the shark, weighing about 500kg (half a ton) landed on top of the bait and fuel containers. At first half of its body was outside the boat but in a
panic the shark thrashed its way further on to the vessel, cutting the fuel lines and damaging equipment before becoming trapped between the containers and the stern. The crew found safety at the bow of the boat.

After radioing for help, the scientists poured water over the white shark's gills to keep it alive. Oceans Research co-directors Enrico Gennari and Ryan Johnson arrived on another vessel and lent a hand tying ropes around the shark's tail in an attempt to pull it back into the ocean.

When that didn't work, the Cheetah was towed back to harbor. A
hosepipe was placed in the fish's mouth to ventilate its gills, before it was lifted off the boat with a crane, then lowered back into the water. But, unable to orient itself out of the harbor, the shark beached itself half an hour later.

With Oceans Research's co-director, Enrico Gennari, an expert on great white sharks, the team tried unsuccessfully to "walk" the shark back to sea. Finally they tied ropes to the shark's tail fin and behind its pectoral fin, and attached these ties to the rescue vessel, which towed the shark out through the
harbor estuary. The ropes were then removed and the animal swam away.

Gennari said it was the first time he had heard of a great white shark jumping onto a research vessel. He estimated the predator would have had to have leaped about three meters out of the water to be able to land on the boat. A smaller vessel would have capsized, he said.

As for the cause of the shark's behavior, Gennari said it was almost certainly an accident rather than an attack on the boat. In the
low-visibility water the fish could have mistaken the vessel's shadow for prey, or been disturbed by another shark close by, he said.

"It's all speculation," he said. "But sometimes a shark breaches the surface when it feels another shark underneath it. They [move] like a flying fish and end up several meters away."

Great White Sharks


Source:
The Guardian,"Great white shark jumps from sea into research boat", accessed July 20, 2011
Shark Chronicles, "Shark Chronicles 091 - 3m Great White Shark breaches into Research Boat", accessed July 20, 2011

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