Human beings overfished fish and shrimp, resulting in insufficient food supply for baiji.

Over-exploitation of the Yangtze River by human beings has seriously damaged the habitat of baiji.

The development of chemical plants and pharmaceutical factories near the Yangtze River has seriously polluted the Yangtze River.

The Yangtze River has become a very busy transport waterway, and many baiji dolphins have been killed and injured by the propellers of ships.

Supplementary information:

Reasons for the endangered baiji dolphin

I. Internal factors

Because it is rare, it is difficult to breed in large quantities.

Low reproduction rate and slow growth.

Two. Human factors

Human beings overfished fish and shrimp, resulting in insufficient food supply for baiji.

Over-exploitation of the Yangtze River by human beings has seriously damaged the habitat of baiji.

The development of chemical plants and pharmaceutical factories near the Yangtze River has seriously polluted the Yangtze River.

The Yangtze River has become a very busy transport waterway, and many baiji dolphins have been killed and injured by the propellers of ships.

Due to the increase of human activities or improper activities, the number of accidental deaths of baiji has increased. According to statistics, during the period of 1973- 1985, 59 * * people died unexpectedly, among which 29 people (48.8%) died from fishing hooks or other fishing gear. 1 1 The head died in the river blasting operation, accounting for18.6%; 12 head was killed by ship propeller, accounting for 20%; 6 heads were stranded and died, accounting for10%; 1 head mistakenly entered the sluice, accounting for 1.6%. According to statistics, one third of the white dolphins who died unexpectedly in the lower reaches of the Yangtze River were killed by ship propellers.

Question 2: Reasons for the Endangerment of Baiji Dolphin In the 1950s, there were still large groups in the Yangtze River, but since then, the number of Baiji Dolphins has dropped sharply and disappeared in lakes and tributaries along the Yangtze River. The number of individuals in the Yangtze River is less than 100, leaving only a section from Zhicheng in the middle reaches of the Yangtze River to Nanjing. According to reports, there were more than 400 bulls in the early 1960s, but it was reduced to more than 300 bulls in the early 1980s. There were more than 200 bulls in the survey of 1990, and more than 130 bulls in the survey of 1993, and 105 was insufficient. 1980 65438+ 10 In October, fishermen in Jiayu County, Hubei Province captured the world's first live male baiji near the mouth of Dongting Lake, and immediately sent it to the Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan City, Hubei Province for artificial propagation. On July 4th, 2002, this baiji dolphin died. 1986, a heifer was captured. Two and a half years later, the female dolphin died of pneumonia. During the period of 1995, a mature female baiji was captured in Shishou River section of Hubei Province and raised on Swan Island in Shishou, Baiji Dolphin Nature Reserve in the old Yangtze River channel. During the summer flood of 1996, this baiji dolphin died because it hit the net. In 2006, a survey of freshwater dolphins in the Yangtze River, the habitat of Baiji dolphins, ended without results. In 2006, a thorough investigation in China found no trace of baiji, and scientists wondered whether this rare species had disappeared from the earth. On August 8, 2007, in a reassessment, the baiji was marked as functional extinction. On August 19, 2007, a citizen of Tongling, Anhui Province accidentally found an animal suspected of baiji in the reach of Tongling Freshwater Dolphin National Nature Reserve and photographed it with a digital camera. 20 10 researchers reported in a new study that according to the memories of local fishermen, they could still find baiji in the middle and lower reaches of the Yangtze River in China even after the deadly decline of this species in the mid-1990s. On July 6th, 2065438+0/kloc-0, fishermen fishing in the Yangtze River found three suspected baiji, which appeared on the Yangtze River. On 2011August 2 1 day, a suspected baiji was found in Honghu section of the Yangtze River. Due to the lack of photographic evidence, the Institute of Aquatic Sciences of the Chinese Academy of Sciences has not made any progress in monitoring and there is no way to confirm it. After receiving the news, the technicians of the Yangtze River Silla Baiji Dolphin National Nature Reserve went to the scene to check, but there was no result. 1978, the Institute of Hydrobiology, Chinese Academy of Sciences established the Baiji Dolphin Research Group. The scientific research of baiji dolphin was officially started. From 65438 to 0978, the State Council promulgated the Regulations on the Protection of Water Resources Reproduction and the General Order on Strict Protection of Precious and Rare Wild Animals, both of which listed Baiji Dolphin as the key protection object. 1979, China declared the baiji an endangered species. 1980 Hubei Province * * * issued the Notice on Protecting the Precious Animal Baiji Dolphin. 1983, China outlawed the hunting of baiji. During the period of 1986, the international symposium on biological protection of freshwater dolphins was held in Wuhan, and baiji became the focus of scientists at home and abroad. In the same year, China Bank Governor Chen donated 500,000 US dollars to Baiji Dolphin. 1992, the Ministry of Agriculture approved the establishment of two national baiji nature reserves in Shishou and Honghu, Hubei, and five protection stations in Jianli, Hubei, Chenglingji, Hunan, Hukou, Jiangxi, Anqing, Anhui and Zhenjiang, Jiangsu. From 65438 to 0993, the International Conference on the Protection of Baiji Dolphin was held in Nanjing. 1February, 1996, the Ministry of Agriculture held an emergency meeting on the protection of baiji to discuss the protection countermeasures. 65438+February 25th, Wuhan Baiji Dolphin Protection Foundation was formally established. In March 2002, Tao Xingshi, a member of the Chinese People's Political Consultative Conference, submitted a proposal to strengthen the protection of baiji at the CPPCC meeting.

Question 3: What are the direct causes of the extinction of giant pandas and baiji dolphins? What are the direct causes of the extinction of giant pandas and baiji dolphins? Biological factors and abiotic factors.

Because giant pandas eat bamboo, and bamboo is a living thing; Baiji dolphin lives in water, which is abiotic.

Baiji dolphin:

1. Over-exploitation of the Yangtze River by human beings has seriously damaged the habitat of the baiji.

People eat too much food.

The exploitation of human beings has caused serious pollution to the Yangtze River.

Biological factors, that is, the activities of any other animals, plants or microorganisms that affect the growth, morphology, development and distribution of organisms, belong to a class of ecological factors and can be divided into intraspecific and interspecific relationships.

Question 4: Why is baiji endangered? 1, the increasingly busy water traffic and the noise of ships make the baiji nervous, and the sonar system fails, so that it is directly killed by the high-speed rotating propeller.

2. Large-scale water conservancy projects, each blasting will cause a fatal blow to the baiji.

3. The rivers cut off by intensive hydropower projects have compressed the living space of baiji, destroyed its habitat and blocked its migration route.

4. The accumulation of industrial sewage and pesticides makes it short of food and its reproductive capacity further decreases.

Question 5: What caused the extinction of baiji? Human behavior is the main reason for the extinction of the baiji. First, it is wanton killing. Secondly, the deterioration of the ecological environment caused by human activities in recent years has led to the extinction of the baiji. The reason why human beings are powerful is that their ability to understand and transform nature has reached an unparalleled height in biological history and biology. But after hundreds of millions of years of evolution and development, it has formed a coordinated and balanced ecosystem. Once destroyed, mankind is still powerless. If humans don't realize the harm of destroying nature, or blindly grab and greedily pursue economic benefits without paying attention to protecting nature, then there will still be the continuous extinction of creatures (in fact, this phenomenon is happening). There are many things that human beings should do. First of all, they should avoid endless development and logging as before, and then they should protect, establish nature reserves, plant trees and so on. In short, fear nature!