Chinese name: Chinese white dolphin
English name: Indo-Pacific humpback dolphin
Latin scientific name: Chinese Sousa Chinensis (Osbeck, 1765)
taxology
Boundary: animals in the animal kingdom
Door: Chordata, Chordata.
Class: mammals
Objective: Cetaceans.
Family: Dolphinidae
Genus: humpback dolphin
Species: Chinese white dolphin
Chinese white dolphin is one of 78 species of whales in the world. For the sake of unification, scholars all over the world call them "Indo-Pacific humpback dolphins" (scientific name is Sousa chinensis), while "Chinese white dolphins" are just local names for them by Hongkong and China residents. Chinese white dolphins belong to the cetacean dolphin family and are close relatives of bottlenose dolphins and killer whales. Many citizens and fishermen think that Chinese white dolphin is a kind of fish. In fact, they are all mammals like other whales and dolphins. Like humans, they can keep the temperature constant, breathe with their lungs, conceive and give birth, and feed their babies with milk. Known as the "giant panda in the Yangtze River", it is a national first-class protected animal.
Some experts in China also believe that the white dolphins produced in the Pearl River Estuary and Xiamen waters have no uplift or humpback at the base of dorsal fin, so the name of Indo-Pacific humpback dolphin or Pacific camel dolphin should be abandoned.
Appearance characteristics
Chinese white dolphins are slender, spindle-shaped and have a long and narrow beak. The body length of white dolphins is about 1 m, and that of sexual mature individuals is 2.0~2.5m, the longest is 2.7m, and the weight is 200 ~ 250 kg. The dorsal fin protrudes and is located near the center, showing a backward triangle; The pectoral fin is round and muddy, with a wide base and extremely flexible movements; The caudal fin is horizontal and firm, divided into two symmetrical leaves with a notch in the middle, which is beneficial for it to swim quickly. Eyes are black and shiny, with 32~36 conical teeth on both sides of the upper and lower jaws, and sparse dentition. The snout is narrow and sharp, long and less than one tenth of the body length. The beak and forehead are clearly separated by a V-shaped groove. There are relatively few vertebrae and the vertebral body is long. There are five fingers on the flippers. The whole body is milky white or ivory, with many tiny gray-black spots scattered on the back and some abdomen slightly pink. The dorsal fin is short, the pectoral fin is thin and round, and the symmetrical triangular caudal fin is almost reddish brown-gray.
The pink color of white dolphins is not caused by pigment, but by blood vessels under the epidermis. This is related to regulating body temperature. Generally, it will gradually fade from the primary dark gray to the adult pink. There will be no fixed members in the white dolphin group except the mother dolphin and the baby dolphin. Their social structure is very flexible, and group members often change. According to the records, there can be up to 23 white dolphins in the group, with an average of 4.
Chinese white dolphins are slender and spindle-shaped.
Type A, with a long and narrow beak, sexual mature individuals is 2.0~2.5m long and 2.7m long, weighing 200 ~ 250kg；; The dorsal fin protrudes and is located near the center, showing a backward triangle; The pectoral fin is round and muddy, with a wide base and extremely flexible movements; The caudal fin is horizontal and firm, divided into two symmetrical leaves with a notch in the middle, which is beneficial for it to swim quickly.
biological property
1. body type
Chinese white dolphin is slender, spiral and has a long and narrow beak. Sexual mature individuals is 2.0~2.5m long, 2.7m long at the longest, and weighs 200 ~ 250kg. Dorsal fin process
Out, located near the center, is a backward triangle; The pectoral fin is round and muddy, with a wide base and extremely flexible movements; The caudal fin is horizontal and strong, with a center.
The notch is divided into two symmetrical leaves, which is beneficial for it to swim quickly. 2. Respiratory system.
Like terrestrial mammals, Chinese white dolphins have developed lungs and breathed with them. The external breathing hole is half-moon-shaped, opening on the top of the head and forehead. When breathing, the head and back
Out of the water, breathe the oxygen in the air directly, and make a jet sound of "Ji Ji-".
3. Automatic position adjustment system
Chinese white dolphins have small eyes, located on both sides of the head, black eyeballs and poor eyesight. Their identification of the position and direction of objects mainly depends on the echolocation system.
System, there is an airbag under the nostril, which makes sound by opening and closing the nasal plug. This kind of sound is concentrated in the unique organ composed of fat at the forehead bulge, according to a certain
Transmit at the frequency of; Signals of different frequencies reflected from different objects are received and transmitted through a groove made of fat in the lower jaw of dolphins.
Enter the inner ear to locate. Although this echolocation system is very complex, its response is extremely fast and accurate, and it can measure the size, shape and density of the object in front.
Structure and attributes, and make judgments and reactions. This special function of dolphins has been studied in bionics by life science departments and military departments.
feed
The feeding and digestive systems of Chinese white dolphins are exactly the same as those of terrestrial mammals, including teeth, esophagus, stomach, liver,
Spleen and intestine. Adult dolphins have 125~ 135 conical teeth in the upper and lower jaws, which are sparsely arranged. Their function is not chewing, but using.
Prey. The feeding object is mainly freshwater fish in the estuary, which can be swallowed quickly without chewing. Anatomical analysis of stomach contents of dolphins
Things, mainly echinococcosis, anchovies, spots? , silver pomfret, black pomfret, white fish, dragon head fish, large yellow croaker, etc.
Common species, mainly feeding on small and medium-sized fish.
5. Reproduction
The life span of Chinese white dolphins is generally 30-40 years, reaching sexual maturity at the age of 3-5, and they can mate all year round. Estrus is mostly concentrated in the warm season from April to September.
Festivals, pregnancy 10~ 1 1 month, each child gives birth to a baby. The newborn dolphin is close to 1m in length, and its tail is first exposed from its mother at birth.
To prevent the baby from suffocating at birth. After birth, her mother will lead her to learn to swim. Female dolphins have milk secretion, and there are 8~20 female dolphins during lactation.
Month. Because the mother and son are inseparable, they are well protected during the whole breastfeeding process, and the survival rate of young dolphins is much higher than that of other aquatic animals.
distribution range
Chinese white dolphins like to live in the estuary where subtropical seawater and fresh water meet, in northern Australia, along the Indian Ocean coast of Africa, and in peaceful Southeast Asia.
It is distributed along the coast of the ocean. Chinese white dolphins are mainly distributed in the southeast coast of China. According to literature, they reach the Yangtze River estuary in the north and Zhejiang in the south.
Coastal estuaries in Fujian, Taiwan Province, Guangdong and Guangxi sometimes enter rivers.
According to the investigation data in recent decades, there are two areas where Chinese white dolphins are concentrated in China, one is the Jiulong River Estuary in Xiamen and the other is the Jiulong River Estuary in Xiamen.
One is at the mouth of the Pearl River in Guangdong.
Chinese white dolphins in the Pearl River Estuary are mainly distributed in Lingdingyang, Wanshan Islands and the southwest waters of Hong Kong. According to 1997~2000 South China Sea Water
According to the survey data of the production institute, the northern boundary of dolphin distribution is in the sea area near Shenzhen Airport, and the southern boundary is in Dong 'ao-Xiaoputai Island. Shovel island in the east,
Chinese white dolphins are distributed in Shenzhen Bay, Lung Kwu Chau, the waters north of the new Hong Kong airport, the coast of Lantau Island, Xiangzhou Bay in the west and the offshore of Macau.
(Figure 4 and Figure 5), the distribution area is not less than 1200km2. The concentrated area of white dolphin activities is mainly in the southeast of Lingdingyang, including Neilingding Island.
Between Wai, Ma Youshi and Lantau Island and near Kameyama Island, the viewing rate of dolphins is high; The occurrence rate of dolphins in the western waters between Qi 'ao Island and Macau.
Lower it. The distribution trend is high in the east and low in the west, with significant difference.
In addition, there are finless porpoises in the Pearl River Estuary. The finless porpoise is a national second-class protected animal. The distribution of finless porpoises is slightly south than that of Chinese white dolphins.
It is often active near Kameyama Island and the waters south of Hong Kong, and the colony size is small, mostly appearing in small groups of 2~5.
There are three main reasons why the Lingdingyang waters in the Pearl River Estuary can become a dense area where Chinese white dolphins gather and inhabit.
1. Salt and fresh water meet, the water quality is fertile, and the water temperature and salinity are suitable for the survival activities of white dolphins;
2. The Pearl River Estuary is rich in biodiversity;
3. The water quality environment is good and the pollution is light, especially along the coast of Neilingding Island and on the west side of Lantau Island, there are still natural coasts.
The route is undeveloped and the water environment is quiet, which is an ideal activity place for Chinese white dolphins.
Living habits
Chinese white dolphins do not integrate into large groups, usually 3-5 dolphins act together or alone. Lively temperament, in sunny weather, often jumping and frolicking on the water, sometimes even jumping out of the water near 1 meter high. Swimming speed is very fast, sometimes reaching more than 12 nautical miles per hour. Breathing intervals are very irregular, sometimes 3~5 seconds, sometimes 10~20 seconds, sometimes 1~2 minutes or more. They mainly feed on fish, including the larvae of Cephalotaxus and Epinephelus, and also eat small yellow snapper and small pomfret. It eats a lot, and the weight of food in its stomach can reach more than 7 kilograms.
Among all kinds of fishing boats, white dolphins especially like to feed behind double tugboats, and the dolphins behind double tugboats are much larger than others. At least 20 different species of fish belonging to 13 families were found in the stomachs of dolphins. The largest number are anchovies, asparagus and herring. Among them, white dolphins like to eat lionfish (Collichthys lucida) best, followed by? Fish (Johnius spp) and yellow croaker (Thryssa spp).
The feeding and digestive system of Chinese white dolphins is completely consistent with that of terrestrial mammals, including teeth, esophagus, stomach, liver, spleen and intestine. Adult dolphins have 125~ 135 conical teeth in the upper and lower jaws, which are sparsely arranged. Their function is not chewing, but hunting. The feeding object is mainly freshwater fish in the estuary, which can be swallowed quickly without chewing. The stomach contents of dolphins were dissected and analyzed, including spiny-headed lizard, water bream and grouper. The common species in the Pearl River Estuary are silver pomfret, black pomfret, whitebait, dragon head fish and large yellow croaker, which mainly feed on small and medium-sized fish.
Like terrestrial mammals, Chinese white dolphins have developed lungs and breathed with them. The external breathing hole is half-moon-shaped, opening at the top of the forehead. When breathing, the head and back are exposed to water, and the oxygen in the air is directly breathed, and the jet sound of "Ji Ji-"is issued.
Chinese white dolphins have small eyes, located on both sides of the head, black eyeballs and poor eyesight. They mainly rely on the echolocation system to identify the position and direction of objects. There is an air bag under the nostril, which makes a sound by opening and closing the stuffy meat. This sound line is concentrated in the unique organ composed of fat at the forehead bulge and emitted at a certain frequency. Signals of different frequencies reflected from different objects are received by the groove formed by the fat in the lower palate of dolphins and introduced into the inner ear for positioning. Although this echolocation system is very complicated, its response is very fast and accurate. It can measure the size, shape, density structure and properties of the object in front, and make judgments and reactions. This special function of dolphins has been studied in bionics by life science departments and military departments.
Growth and reproduction
The life span of Chinese white dolphins is generally 30-40 years, reaching sexual maturity at the age of 3-5, and they can mate all year round. Estrus is mostly concentrated in the warm season from April to September, and the pregnancy period is 10~ 1 1 month, and each child gives birth. The newborn dolphins are close to 1m in length, and the baby's tail is exposed from the mother at birth (the head of terrestrial mammals is exposed first) to prevent the baby from choking to death at birth. After birth, her mother will lead her to learn to swim. Female dolphins have milk secretion and breastfeed for 8~20 months. Because the mother and son are inseparable, they are well protected during the whole breastfeeding process, and the survival rate of young dolphins is much higher than that of other aquatic animals.
Female dolphins will reach maturity at 10- 1 1 year. Dolphin babies are born all year round, but the birth rate is slightly higher in spring and summer. In other areas, the longest life span of white dolphins is 40 years. In Hong Kong, the oldest dolphin is 33.
Chinese white dolphins mainly mate in water from June to July every year. The pregnant period of a female is about 65,438+00 months, and her cubs are born from March to April of the following year. The tail of the calf, sir. The head is finally exposed. The length of the newborn is about 100 cm, which is about13 of that of the female. The back is gray-black, the abdomen is white and pink, the teeth are not exposed, and there are more than 10 sensory hairs on the snout. The lactation period is about 1 year. At this time, all the hair falls off and the teeth grow out completely, reaching sexual maturity in 2~3 years. Life expectancy is generally 25~35 years old.
related data
Chinese White Dolphin and the Return of Hong Kong
The Chinese white dolphin was also chosen as the mascot of 1997 to celebrate the return of Hong Kong. At the ceremony to celebrate the establishment of the Committee for the Return of Hong Kong to the Motherland, the emblem of the large-scale Committee hung on the rostrum was particularly eye-catching: a lively and lovely Chinese white dolphin was jumping and frolicking on the waves, with the regional flag and emblem of the Hong Kong Special Administrative Region as the main body in the middle and five-star bauhinia, and the outer ring was the Chinese and English name of the Committee. The composition of the emblem reflects the joy of Hong Kong people's longing to return: the waves have both round waves and long ripples, symbolizing joy and celebration, while the bauhinia with red background and white flowers is located between the Chinese white dolphins and the waves, showing the hearts of Hong Kong people.
The Chinese White Dolphin was chosen as the mascot to welcome the return to China because of its special symbolic significance. First of all, Chinese white dolphins have a deep relationship with Hong Kong. In the western waters of Hong Kong, especially in the areas of Lung Kwu Chau and Sha Chau, groups of Chinese white dolphins can often be seen. Chinese white dolphin is a precious animal in the ocean, and Hong Kong is an important port city, which cannot be separated from the ocean. Secondly, the Chinese white dolphin has the word "China" in its name. Every year, Chinese white dolphins swim back to the Pearl River Delta and other places to breed their offspring. They have the quality of not forgetting and loving their homeland. As an inseparable part of China, Hong Kong should return to the motherland. Thirdly, Chinese white dolphins like to live in groups and have a strong sense of family attachment. In particular, females take good care of their young. When their young are caught near the fishing net because they are greedy for small fish that have been online, females will wander around the fishing net anxiously, seeking ways to rescue their young, and even risk their lives to attack the fishing net to save their young. Their feelings are very touching. It is these characteristics that express Hong Kong people's desire to return to the embrace of the motherland.
The special status of Chinese white dolphins in the return of Hong Kong has also played a positive role in wildlife protection. In order to protect the Chinese white dolphins, the Hong Kong government first set up a marine park reserve in the waters of Lung Kwu Chau. On the occasion of Hong Kong's return to the motherland, Hong Kong established the "Chinese White Dolphin Resource Center", which was initiated and organized by some environmental groups to save the Chinese white dolphins. According to the survey, there are about 60~80 Chinese white dolphins in Hong Kong waters. In recent years, due to the change of water quality, about 10 dolphins die every year. After the establishment of the organization, various measures will be taken to purify the water quality in the living area of Chinese white dolphins, balance the ecological environment and provide good living conditions for Chinese white dolphins. At the same time, extensive publicity activities will be carried out to let more people know about the bad situation faced by Chinese white dolphins and attract more people to participate in the rescue operation.
Correspondingly, in August of 1997, a nature reserve with a total area of 5,500 hectares was established in Xiamen, Fujian, one of the main habitats of Chinese white dolphins. On June 65438+1October 1 1 day of the same year, the Xiamen Municipal Government issued the Regulations on the Protection of Chinese White Dolphin in Xiamen, and jointly undertook the obligation to protect this rare "national treasure at sea" with Zhangzhou and Quanzhou, which are adjacent to Xiamen. Chinese white dolphins are the only national first-class protected animals in Xiamen, and they are called "Mazu fish" and "real harbor fish", because this is also the time when a large number of Chinese white dolphins appear in Xiamen waters during the spring sacrifice to the sacred "Mazu", and whenever they appear, the sea is always calm, so fishermen used to burn incense and kowtow for protection when working at sea. However, in recent years, the original number of ordinary Chinese white dolphins has obviously decreased due to the reasons such as embankment construction, capture and accidental capture, and poor ecological protection in marine engineering construction.
Provisions of Xiamen Municipality on the Protection of Chinese White Dolphins
Regulations on the Protection of Chinese White Dolphins in Xiamen
Promulgated by Xiamen Municipal People's Government
DocumentNo. Decree No.65 of Xiamen Municipal People's Government
Promulgated in1997-10-18.
Implementation time: 1997- 12- 1
Validity attribute is valid.
Article 1 In order to protect the precious and endangered Chinese white dolphin resources and their living environment, and maintain ecological balance, these Provisions are formulated in accordance with the provisions of the Law of People's Republic of China (PRC) on the Protection of Wild Animals and the Regulations for the Implementation of the Protection of Aquatic Wild Animals in People's Republic of China (PRC), combined with the actual situation of this Municipality.
Article 2 Xiamen Chinese White Dolphin Nature Reserve is under non-closed management, and its scope is defined as the first pier and the west sea area north of Songyu Line and south of Gaoji seawall, as well as the Tongan Bay mouth sea area of Zhongzhai, Liuwudian, Aotou and Wu Tong.
Other sea areas within the administrative area of this Municipality are the peripheral protection zones of the protected areas.
Article 3 All units and individuals have the obligation to protect the resources of Chinese white dolphins and their living environment, and have the right to supervise, report and accuse all acts that destroy the resources of Chinese white dolphins and their living environment.
Article 4 The Municipal People's Government shall set up special funds for the protection and development of Chinese white dolphins, which shall be used exclusively for the protection of Chinese white dolphin resources, the construction of Xiamen Chinese white dolphin nature reserve, scientific research, publicity and education and other activities.
Encourage domestic and foreign organizations and individuals to donate money to protect the resources of Chinese white dolphins and their living environment.
Article 5 The municipal fishery administrative department and its subordinate fishery agencies shall be responsible for the construction and management of Xiamen Chinese White Dolphin Nature Reserve, and supervise and inspect the protection of Chinese White Dolphin resources and their living environment.
The relevant administrative departments of transportation, harbour superintendency administration and marine affairs shall, in accordance with the provisions of relevant laws and regulations, closely cooperate with each other according to their respective responsibilities, and do a good job in protecting the resources of Chinese white dolphins and their living environment.
The competent administrative department of environmental protection shall supervise and coordinate the management of Xiamen Chinese White Dolphin Nature Reserve according to law.
Article 6 The municipal fishery administrative department shall organize the investigation of Chinese white dolphin resources, establish resource files, formulate protection and development plans, implement the construction of nature reserves and various management systems, organize scientific research and academic exchanges, take effective measures to maintain and improve the living environment of Chinese white dolphins, and protect and proliferate Chinese white dolphin resources.
Seventh to strengthen the publicity of Chinese white dolphins related laws and regulations, popularize the scientific knowledge of Chinese white dolphins and rescue measures, and enhance public awareness of protecting Chinese white dolphins.
Article 8 The municipal fishery administrative department shall organize and implement the artificial release of Chinese white dolphins regularly or irregularly to increase aquatic resources and enrich bait.
Article 9 According to the functional zoning of Xiamen sea area, mariculture in the western sea area shall be restricted, the scale of mariculture in Tongan Bay estuary shall be moderately controlled, and certain freedom of activities of Chinese white dolphins shall be guaranteed.
Article 10 When any unit or individual finds that the Chinese white dolphin is injured, stranded or trapped by mistake in the port, it shall take emergency rescue measures in time and report to the municipal fishery administration for handling; Those who are mistakenly arrested shall be released in time; The dead Chinese white dolphin should be reported or sent to the municipal fishery administration for treatment in time.
Eleventh it is forbidden to kill Chinese white dolphins. Scientific research and resource investigation of Chinese white dolphins, and artificial breeding of Chinese white dolphins, which need to obtain natural water provenance, shall apply to the municipal fishery administrative department according to law. After signing the opinions, the municipal fishery administrative department shall apply to the fishery administrative department of the State Council for a special fishing license and accept the supervision of the municipal fishery administrative department.
The professor of Xiamen University first proposed the safe distance of underwater blasting to protect Chinese white dolphins.
Xiamen has made new progress in the protection of Chinese white dolphins, and put forward a semi-empirical formula for the relationship between underwater blasting sound pressure, charge and action distance in Xiamen Port for the first time.
Xu Xiaomei, a professor in the Department of Oceanography of Xiamen University, learned that the research on the influence of underwater blasting and other operations on Chinese white dolphins and the construction of underwater acoustic monitoring system organized by Xiamen Ocean and Fisheries Bureau have recently passed the evaluation of relevant experts.
According to this research, Xiamen * * * has made three important research achievements in the protection of Chinese white dolphins.
Firstly, a set of "underwater blasting remote underwater acoustic monitoring system" is developed by using advanced underwater acoustic data acquisition and signal processing, CDMA wireless transmission and client/server mode information service technology.
Secondly, the threshold of minimum sound pressure peak (minimum sound pressure level) caused by underwater blasting shock wave to Chinese white dolphins is obtained, and the semi-empirical formula of the relationship between underwater blasting sound pressure and explosive quantity and action distance in Xiamen Port is put forward for the first time.
Thirdly, on the basis of theoretical research, a set of underwater acoustic signal driving device is developed by ourselves, and important technical parameters are obtained.
According to reports, these three achievements will be directly applied to the practical work of white dolphin protection: on the one hand, it provides a scientific basis for the competent authorities to determine the safe distance of underwater blasting of Chinese white dolphins; On the other hand, it is beneficial to strengthen the all-weather supervision of underwater blasting engineering.
According to public information, the Chinese white dolphin is a national first-class protected aquatic wild animal, known as the "aquatic giant panda", and Xiamen sea area is one of the main habitats of the Chinese white dolphin.
In recent years, with the increase of marine engineering projects in Xiamen and its surrounding waters, the ecological environment of marine life such as Chinese white dolphins has been seriously affected.
Risk factor
1. Reclamation
Land reclamation is the most common land reclamation method on both sides of the Pearl River Estuary. In the land-rich Pearl River Delta, is it to build docks and roads, to develop real estate or to expand agriculture?
The construction of fields and breeding bases often faces the sea. Reclamation is not only a private contract, but also the behavior of many government departments.
The biggest harm of land reclamation is the destruction of coastal ecological environment, the destruction of natural mangroves, the erosion of beaches and the shrinkage of estuary waters.
Narrow, intertidal creatures and shallow-sea fish lost their homes, and the traditional natural spawning grounds and breeding grounds of many kinds of fish and shrimp were destroyed in the roar of bulldozers.
Due to land reclamation, the range of activities of Chinese white dolphins has gradually narrowed, and there are fewer places to feed. The variety and quantity of food are also influenced by intertidal organisms.
Decline, become more and more monotonous and poor.
2. Blasting
At the same time of land reclamation, heavy explosives are often used in mountain blasting, island quarrying, mountain moving and sea filling, underwater blasting and other operations, forming a powerful
The shock wave of power made the earth shake, the tsunami surged, and a large number of gravel splashed into the sea. From 1993 to 65438+February, there were many blasting constructions in Sanzao Island, Zhuhai.
The first dolphin died, from 1993 to 1995. During the construction of the new airport at Chek Lap Kok, Hong Kong, many white dolphins were injured.
Dig sand
Infrastructure projects need a lot of sea sand, and dozens of sand dredgers operate in the Pearl River Estuary every day. Dredging not only destroyed the seabed, but also seriously damaged it.
The habitat environment of aquatic organisms, fish, shrimp, shellfish, algae and insects are all sucked away by the dredging machine, and the sea area becomes barren, and the original benthic organisms and fish and shrimp breeding areas are no longer available.
Re-exist. At the same time, dredging also stirred the bottom mud, causing secondary pollution, and the water body was very turbid, which affected the normal ecological and physiological activities of white dolphins.
Move it. The Guangdong provincial government has ordered a ban on coastal dredging, which is a policy guarantee for protecting the habitat of white dolphins in the future.
4. Overfishing in fisheries
This is also an important reason for the sharp decline of fishery resources in the Pearl River Estuary. Fishing boats enter the Pearl River Estuary every year, such as Panyu, Zhuhai and Dongguan.
There are many floating fishing boats in Shenzhen and Hong Kong, as well as hundreds of fishing boats in Taishan, Yangjiang, Chenghai and Raoping. Operation mode has a single drag,
Fishermen complain about double towing, diving in the sea, dragging shrimp, stinging people, setting up, etc. If you drag it down day and night, several layers of skin will be scraped off the bottom of the sea and the fish will become thinner and thinner.
(small), the output is getting lower and lower. "Thus, the destruction of fishery resources is serious.
Due to the transition of fishing moratorium, the Pearl River Estuary has been in the off-season in recent years, and a large number of fishing boats have stopped sailing. Cool fishing and overfishing make life difficult for fishermen's white dolphins.
It is also a difficult time. Disordered gill nets and trawls increase the probability of white dolphins being injured, while illegal activities such as electricity, frying and poisoning fish are all white.
The biggest threat to the survival of dolphins. The fertile estuary fishing ground attracted white dolphins to recuperate here, but now the food of white dolphins has become a problem. No fish.
It can be found that food does not cover the stomach. If strong measures are not taken (such as artificial reefs), white dolphins will only migrate or die, and there is no other way out.
Road.
5. There are frequent ships coming and going
The Pearl River Estuary is one of the busiest sea areas in China and even the world, with contacts between Hong Kong and Macao, between Guangzhou and Hong Kong, and between Shenzhen and Zhuhai. There are also cities in Guangzhou and the Pearl River Delta.
Class I ships include ocean-going ships, large and small passenger ships, high-speed clippers, and various cargo ships, fishing boats, tugboats, engineering ships, oil tankers, etc. Go through.
Shuttle, so that the entire Pearl River estuary is very lively, but also let the white dolphins fidget. The survival of white dolphins depends on its special echolocation system for information transmission and search.
Yes, but the noisy ship mechanical noise interferes with the sound wave propagation of dolphins, making them unable to accurately judge the environmental threat and being cut off in serious cases.
Get killed According to fishermen, white dolphins killed by jet hydrofoils are sometimes seen on the Hong Kong-Macao route north of Kameyama Island.
6. Industrial wastewater and domestic sewage discharge
The Pearl River Delta is an economically developed area, with thousands of factories in the upper reaches, especially the coastal paper mills, chemical plants, electroplating plants, printing and dyeing plants and other types.
Undoubtedly, the industrial wastewater in the Pearl River Estuary directly destroyed the natural fishing grounds and spawning grounds in the Pearl River Estuary, and cut off the food sources of Chinese white dolphins. The white dolphin is right on this point.
Some toxic and smelly wastewater will instinctively avoid swimming. Because the relevant departments have taken various environmental protection measures, including "discharge up to standard and total amount control"
In recent years, the environmental quality problems in the Pearl River Estuary have been alleviated, but at present, the water quality problems of organic nitrogen and petroleum are still serious.
7. Pesticide pollution
Pearl River Delta is a subtropical economic crop producing area, and various pesticides, herbicides and organochlorine pesticides are also destroying the fishery resources in the Pearl River Estuary.
Factors are also a threat to the survival of white dolphins. According to reports, from the tissue analysis of the dead Chinese white dolphins, it is found that the Chinese white dolphins in the Pearl River Estuary
The contents of pesticides DDT and polychlorinated biphenyls (PCB) are higher than those of cetaceans in other parts of Asia. This phenomenon may be accumulated in the body by white dolphins through the food chain.
Result. When these substances accumulate in white dolphins to a certain extent, they will destroy their reproductive and immune systems. Obviously, pesticide pollution in the Pearl River Estuary is harmful to China.
The survival threat of white dolphins can not be ignored.
8. Oil pollution
In recent years, oil spills have occurred from time to time when oil tankers collide in the Pearl River Estuary, especially the oil spill, which has formed a large oil film on the sea surface, blocking seawater and
The normal exchange of air is easy to cause hypoxia in water, pollute fish and cause fish to die of hypoxia. For example, the "Donghai 209" occurred on1March 24th, 999.
The oil tanker "Gong Mingong No.2" collided in Lingdingyang, causing the oil tanker to sink, and more than 800 tons of heavy oil leaked out, with a polluted area of 300km2. Zhuhai has a coastline of 40 kilometers.
Serious pollution has brought great losses to coastal aquaculture farms and large mangroves. If the white dolphin is polluted by oil, it will definitely float and breathe.
When exposed to oil pollution, oil pollution may be inhaled into the lungs when breathing, and the consequences will inevitably endanger the survival and health of white dolphins.
9. Waste dumping area
There are many garbage dumping areas in the Pearl River Estuary, one in the east and the other in the west of Neilingding Island. In the southeast waters of Shazhou Island, there is also a kind of incense.
Sludge dumping area designated by the Hong Kong government. Most designated dumping areas are set by government departments. As for a large amount of civil garbage, it is thrown into the river casually and finally floated.
There are countless wastes and sludge flowing to the Pearl River Estuary. These wastes and sludge often contain a lot of heavy metals and toxic substances, which not only pollute the seabed and water quality, but also sometimes
It will also be poisoned by fish and various organisms and accumulate in the body, and enter the white dolphins through the food chain.
10. Your own weaknesses
Although Chinese white dolphins have many adaptations to aquatic life, their inherent physiological characteristics of terrestrial mammals, such as viviparous, breastfeeding and breathing with lungs, also
This is one of the factors leading to the current endangerment. 10 The pregnancy time is long, the number of one child is small, and the lactation period is long, which makes some babies die young. Besides, I strayed into the river.
Most dolphins are also in trouble.
Protective action
1988 The List of Key Protected Wild Animals in People's Republic of China (PRC) issued by the State Council listed the Chinese white dolphin as a national first-class protected animal.
Things, but also included in the convention on international trade in endangered wildlife;
1In May 1994, IUCN/SSC/CSG held an international cetacean expert group meeting in Guangzhou.
Issue an appeal to protect Chinese white dolphins;
1In May, 1995, IUCN/SSC/CSG held a seminar on cetacean protection in Fujian, Hong Kong and Taiwan, which suggested that Fujian and Hong Kong should set up protection respectively.
Chinese White Dolphin Reserve;
1In July 1996, the Agriculture and Fisheries Department of the Hong Kong Government hosted an international conference to discuss the protection of Chinese white dolphins in Hong Kong. 1October, 165438+ The Hong Kong Government held water fairs in Sha Chau and Lung Kwu Chau.
Establish marine park reserves in the region to protect Chinese white dolphins; In the same year, Taiwan Province Province also set up a project to save Chinese white dolphins in Taiwan Province Province (Kinmen);
1997 the hong kong special administrative region has designated the Chinese white dolphin as the mascot of hong kong's return to the motherland.
1In August, 1997, Fujian Provincial People's Government approved the establishment of Xiamen Chinese White Dolphin Nature Reserve. 1999165438+10 was promoted to a national nature reserve in October;
1999 10 Guangdong provincial government approved the establishment of the Pearl River Estuary Chinese White Dolphin Provincial Nature Reserve, which was upgraded to a national nature reserve in June 2003.
Area;
From June, 5438 to October, 2003, Dongshan, Fujian-Nan 'ao, Guangdong was included in the United Nations marine biodiversity protection demonstration zone, and the key protection targets were determined as follows.
Chinese white dolphin; In August of the same year, Shantou City, Guangdong Province established two Chinese White Dolphin Municipal Nature Reserves in Laiwu Sea and Longtouwan Sea respectively.
In February, 2004, the first seminar and working meeting on the protection of Chinese white dolphins in Taiwan Province waters was held in Taiwan Province Province. I hope it helps you!