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A whale watching observer from Monterey, California, shot a large proportion of dolphins jumping from several hungry orcs.
USA DENES

After all, the big white shark can not be the main predator of the ocean.

Scientists have found that white sharks not only escaped whale killers when they arrived at a seaside sanctuary near San Francisco, but cleared to the next season.

"When faced with an orca, white sharks will immediately leave their preferred hunting ground and will not return for up to a year, although orchards are only passing through," said Salvador Jorgensen, a senior research scientist in the aquarium in Monterey Bay and the leading author of the study.

Minutes after the orc appeared to feed the elephant seals, the researchers say that white sharks began to swim in the ground or sink together in other seal colonies farther from the coast.

Some of the white sharks that usually dominate the shrine span more than 18 meters, says scientist from Monterey Bay Aquarium Scott Anderson.

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The researchers compared data from electronic tags to track sharks and field observations of Orca's remarks. The researchers say that predators often do not encounter one another in the National Sea Sanctuary of Greater Faralone, because occasionally the orchestra only visits the area, while white sharks usually gather for more than a month each fall.

Similar seals also benefited from interaction, a study found, suffering from four to seven times fewer attacks in the years sharked white sharks. The researchers looked at 27-year surveys of the seal, orc and sharks in the area, in addition to 165 white sharks marked between 2006 and 2013.

"After the appearance of the orc, we do not see any sharks and no more killing," Anderson said.

The study did not conclude whether the orcs were hunting white sharks or harassing their competition, but Jorgensen says the survey shows how interactions among top predators affect food chains.

The dynamics between marine predators is more difficult to observe than those on land, he added, noting that it could take longer to understand the relationship between orch and white sharks because they meet so rarely.

"We do not usually think how fear and risk aversion could play a role in shaping the great hunters hunting and how it affects ocean ecosystems," Jorgensen said. "It turns out that these risky effects are very strong even for large predators such as white sharks – strong enough to divert their hunting activities to less preferred but safer areas."

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