The study is worrying: 92% of the world's sharks have been

The number of sharks in Australia has decreased by 92%. And according to experts, that trend is spreading all over the world.

Perhaps many people also guess that: like many other creatures in the world, the number of sharks is decreasing year by year. But to what extent do you know?

According to a recent study in Australia, the number of sharks - particularly white sharks, tiger sharks and hammerhead sharks - has dropped by more than 90% compared to the same period. 50 years ago. But more seriously, experts believe that this is a common ratio with other shark species in the world.

The number of white sharks, tiger sharks and hammerhead sharks in the Australian waters is severely reduced.

Specifically, the researchers used data from the Queensland shark control program in the 1960s, to reduce shark attacks in the region. The program uses fake primers and crank nets around the Australian coast, stretching for thousands of kilometers.

It is estimated that about 50,000 sharks have been caught in the net since this period. However, over time, the proportion of sharks that catch nets is decreasing.

"We recognize that large shark species such as hammerhead sharks, tiger sharks and white sharks have experienced a decline in numbers, with rates ranging from 74% to 92%" - quoted Dr. George Roff from the University of Queensland.

"And the proportion of fish without nets has increased 7 times per year."

Roff also noted that it was difficult to know the number of fish before the control program in 1960, but based on the documents, he said that the Australian sea was " really filled with sharks" . In particular, more than half are varieties found worldwide.

A hammerhead shark is wrapped around the body by a net.

In fact, reports in recent years have recorded an increase in the number of victims attacked by sharks, which means the number of sharks is growing. However, Roff said his report points to the opposite, that many sharks are in danger, leading to the need to appear near shore.

"The long-term trend shows the decline of sharks. Although they are always considered dangerous animals, they still play an important role in marine ecosystems," Roff said.

According to Roff, one of the reasons for the number of hard-to-recover sharks is the fish control programs like the Australians are doing. In addition, human activities such as indiscriminate fishing, environmental pollution, destruction of ecosystems also make this animal gradually fall into extinction.

The study is published in Communications Biology.