What? Three-quarters of shark species are endangered? They are also a great threat to humans

Expert of this article: Liu Yadan, researcher, deputy secretary-general of China Agricultural International Exchange Association, national chief scientific communication expert

Recently, a survey report on sharks in the journal Nature has attracted public attention, emphasizing that there are no sharks near many coral reefs around the world, which means that the number of sharks is so small that they can no longer play a normal role in the ecosystem.

Research data shows that in the past 50 years, the number of sharks has dropped by 71%. Not only that, three-quarters of shark species are on the verge of extinction.

Shark and ray populations have dropped 71 percent in the past half century since 1970.

Sharks have survived for at least 420 million years. Some data say that sharks have survived four of the five major extinction events on Earth, one of which had a great impact on them, and many shark species have disappeared. Otherwise, there would be more sharks now, and they would compete with other overlords in the ocean from generation to generation.

What is causing them to be on the verge of extinction?

Why are sharks endangered?

Humanity’s excessive demand on marine resources

Over the past 50 years, the population has also grown rapidly, and the demand for various resources has also continued to grow, especially since some people mistakenly believe that marine resources are inexhaustible. The development of science and technology over the past half century has also made it easier for humans to obtain marine resources.

Marine environmental pollution

The increasing population density in coastal cities has led to an increasing number of pollutants entering the ocean, and water pollution is becoming increasingly serious. It is reported that even the oceans in the polar regions, which we have always believed to be pure, have not escaped the fate of being polluted. For marine life, pollution is the biggest threat to their survival, and there are countless reports of animals dying from human garbage.

Overfishing

In pursuit of economic benefits, some places overfish sharks. Lack of scientific publicity and protection will lead to overfishing of sharks. Currently, many countries and regions have begun to pay attention to the protection of sharks and have divided relevant protected areas, but not all sharks in all seas have been effectively protected.

Sharks reproduce slowly

Sharks have a long lifespan and a long growth cycle, and reproduce very slowly. Many species of sharks only give birth once every two years, and it is difficult for young sharks to survive. Now that their habitats are becoming increasingly unstable, they are unable to sleep or eat, and have no interest in reproduction, so it is inevitable that they will eventually become "functionally extinct."

What impact would shark extinction have on humans?

Sharks are top predators and play a very important role in maintaining the ecological balance of the ocean.

Sharks have evolved for 400 million years, but they still maintain their original appearance, which is also a miracle. Studying the life history of sharks is of great significance to studying the evolution of life on Earth.

We all know that sharks are ferocious. In fact, saying that sharks are scary is a misunderstanding.

Sharks come in all sizes, ranging from 6 inches to 18 meters in length. The smallest shark is the pygmy dogfish, which is small enough to fit in your hand. It is not even as big as a yellow croaker and weighs less than a pound.

Despite their large size, whale sharks have the smallest teeth of any shark.

There are about 380 shark species in the world, and less than 1/10 of them, only 30 species, will hurt people, but they will not take the initiative to hurt people. According to research, most of the reports of sharks hurting people are accidental injuries, and only 7 species are more aggressive.

There are another 27 species of sharks that, because of their large size, could cause collisions with ships or capsizes if human activities disturb the waters where they live and disturb them.

As carnivores at the top of the marine food chain, sharks like to eat meat, but human meat cannot provide them with high fat, so it is not on sharks' menu.

Their favorite food is turtles, whales, sea lions, seals and various small and medium-sized fish, because sharks' huge bodies require them to eat a lot of meat to maintain the energy required for activities.

Therefore, the purpose of sharks biting people is not to eat them!

What other marine life is endangered?

The ocean world is very lively. According to research, there are far more than the 210,000 species of marine life that we know of currently, perhaps 10 times more.

Under the conditions of unpredictable global climate change, coupled with various problems such as marine pollution, overfishing, and offshore engineering, the life and habits of organisms in the ocean are undergoing varying degrees of changes. For example, coral bleaching is a serious global problem. There are also some large animals that have a long history, grow slowly, and have extremely long lifespans, such as the Greenland shark, which can live for about 500 years.

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There are many giant ocean predators that are listed on the list of my country's first-class protected animals, including our whale brothers, such as the gray whale, blue whale, minke whale, Bryde's whale, fin whale, sperm whale, and the strange and elegant-looking rays that can fly in the sea, which are the flying Wen Yao fish described in "Shan Hai Jing". In recent studies, their numbers have also been shown to have decreased sharply.

Biological protection is imperative!

How to protect endangered marine animals?

To protect sharks, we must strictly manage and protect the marine environment. In addition, it is also important to raise public awareness.

We must strengthen publicity, education and knowledge dissemination on marine biological protection, and guide and motivate the general public to actively participate in biological protection.

One of the reasons why sharks are hunted in large numbers is that many people believe that shark fins have high nutritional value. Shark fins are made from the dried fins of the shark's chest, abdomen, tail, etc.

But in fact, the nutritional value of shark fin is similar to that of eggs, so we should consciously limit and resist the demand for sharks.

Protecting various marine life, including sharks, and maintaining the balance of marine ecology is the common responsibility of the whole world.

Once these creatures become extinct, it will be a great threat to nature and humans!

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