The Chinese White Dolphin is one of the seventy-eight species of whales in the world; for the sake of unification, scholars all over the world call them
It is the "Indian Pacific Camelback Dolphin" (scientific name Sousa chinensis), and "Chinese White Dolphin" is the local title given to them by Hong Kong and Mainland China residents. The Chinese white dolphins belong to the dolphins of the cetaceans and are close relatives of bottlenose dolphins and killer whales. Many people and fishermen think that Chinese white dolphins are a kind of fish. In fact, they and other whales and dolphins are mammals. Like humans, they can keep warm, use lungs to breathe, give birth and feed their children with milk.
Some experts in China believe that the white dolphins produced in the Pearl River Estuary and Xiamen waters have no bulge at the base of the dorsal fins and are not hunched. The names of Indian Pacific humpback dolphins or Pacific dolphins should be abandoned.
Appearance feature
The Chinese white dolphin has a slender body shape with a long and narrow shape. The newly born white dolphin is about 1 meter long. The sexually mature individual has a body length of 2.0 to 2.5 m, a maximum length of 2.7 m and a body weight of 200 to 250 kg. The dorsal fin is prominent and is located near the center. At the site, it has a posterior tilting triangle; the pectoral fin is rounder, the base is wider, and the movement is extremely flexible; the caudal fin is horizontal, strong and powerful, and the central nick is divided into two symmetrical leaves, which is conducive to rapid swimming. The eyes are black and bright, with 32 to 36 conical teeth on each side of the upper and lower jaws, and the dentition is sparse. The snout is narrow, pointed and long, and the length is less than one tenth of the length of the body. The sputum and the forehead are clearly separated by a "V" shaped groove. There are relatively few vertebrae and the vertebral body is longer. There are 5 fingers on the fins. The whole body is ivory or milky white, with many tiny gray-black spots on the back, some with pinkish abdomen, short dorsal fins, thin round pectoral fins and well-balanced triangular caudal fins that are almost reddish brownish brown [1] ] .
The pink color of the white dolphin is not caused by pigmentation, but by the blood vessels under the epidermis. This is related to the regulation of body temperature. It usually fades from the dark gray of the newborn to the adult pink. In addition to mothers and young dolphins, the white dolphins group does not have a fixed membership. Their group structure is very flexible, and members of the group are often replaced. According to the records, the group can have up to 23 white dolphins, with an average of four.
Respiratory system
The Chinese white dolphins are as well developed as the terrestrial mammals and breathe with the lungs. The outer breathing hole is open to the top of the forehead in a half-moon shape. When breathing, the head and back are exposed to the water surface, and the oxygen in the air is directly breathed, and a "Chi-Chi-" jet sound is emitted.
The Chinese white dolphins have smaller eyes and are located on both sides of the head Chinese white dolphins. The eyeballs are black and their vision is poor. The position and direction of the objects are mainly determined by the echolocation system. There is a balloon under the nostrils, and the opening and closing of the nose is sounded. The sound line is concentrated in a special organ composed of fat at the forehead ridge, and is emitted at a certain frequency; the sound encounters different frequency signals reflected by different objects, and is received by a dolphin squatting a groove composed of fat. Into the inner ear for positioning. Although this echolocation system is complex, the response is extremely fast and accurate. It can measure the size, shape, density structure and properties of the front object, and make judgments and reactions. This special function of dolphins has been studied by the life sciences department and the military department for bionics research.
The feeding Digestive System of the Chinese white dolphins is identical to that of the land mammals, and has teeth, esophagus, stomach, liver, spleen and intestines. Adult dolphins have 125 to 135 taper teeth in the upper and lower jaws. They are sparsely arranged. Their function is not to chew, but to prey. The feeding objects are mainly salty freshwater fish in the estuary, which can be swallowed quickly without chewing. The anatomical analysis of the stomach contents of dolphins mainly includes the common cultivars of the Pearl River estuary such as the thorny plum carp, phoenix phoenix, plaque, silver carp, black carp, white mullet, faucet fish, and large yellow croaker. The food is mainly small and medium-sized fish. .
Living habit
Chinese white dolphins do not integrate large groups, often 3 to 5 together, or alone. Lively, in the wind and sunny weather, often jumping on the water, sometimes even jumped out of the water nearly 1 meter high. Swimming is fast, sometimes up to 12 nautical miles per hour. The interval of breathing is very irregular, sometimes 3 to 5 seconds, sometimes 10 to 20 seconds, and sometimes as long as 1 to 2 minutes or more. It mainly feeds on fish, including larvae of the genus Polygonaceae and the genus Panicidae, as well as small scutellaria and small squid. It has a large amount of food, and the weight of food in the stomach can reach more than 7 kilograms.
Among the various fishing boats, the white dolphin particularly likes to eat after double tugs, and the dolphins group after the double tug is much larger than the others. A minimum of 13 families and 20 different fish species were found in the stomach of the dolphins. The largest number is the scorpion, the stone family and the scorpion. Among them, the white dolphins like to eat the lionfish (Collichthys lucida), followed by the squid (Johnius spp) and the yellow squid (Thryssa spp). There are mainly common varieties of the Pearl River estuary such as the thorny plum carp, phoenix carp, silver carp, black mullet, white gutta, faucet fish, and large yellow croaker. The feeding habits are mainly small and medium-sized fish.
Growth and reproduction
The life span of Chinese white dolphins is generally 30 to 40 years. Sexual maturity reaches 3 to 5 years old. It can be mated all the year round. The estrus period is mostly concentrated in the warm season from April to September. The pregnancy period is 10 to 11 months. A child. The newborn baby has a body length of nearly 1 m. When the larva is born, the tail is exposed from the mother (the head of the terrestrial mammal is exposed first) to prevent the baby from dying during birth. After birth, the mother is led to learn to swim. The dolphins have milk secretion, and the lactation period is 8 to 20 months. Because the mother and child are inseparable during the whole feeding process, and the protection is good, the survival rate of the young dolphins is much higher than that of other aquatic animals. Female dolphins will reach maturity when they are 10 to 11 years old. The baby dolphins will be born throughout the year, but the birth rate is slightly higher in spring and summer. In other regions, the life of the white dolphin is up to 40 years old. In Hong Kong, the oldest dolphins are 33 years old. The Chinese white dolphins are mated in the water mainly from June to July each year. The gestation period of the female is about 10 months. The larvae are born in March to April of the next year. The tails of the young ones are produced first, and the head is finally exposed. The newborn baby has a body length of about 100 cm, about 1/3 of the length of the female body, grayish black on the back, white and pink on the ventral surface, teeth are not exposed, and there are more than 10 feelings in the kiss. hair. The lactation period is about 1 year. At this time, it is felt that the hair is completely shed, the teeth are completely grown, and sexual maturity is reached in 2 to 3 years. The life expectancy is generally 25 to 35 years old.
Excessive high dolphins mortality ( From Hong Kong Dolpinwatch Ltd )
At least half of the dolphins found in Hong Kong each year are newborn dolphins. After dissection, they found only breast milk in their stomachs and no fatal scars. Organochlorinated substances such as banned pesticide DDT and electronic industry common chemicals PCB and other toxic substances will accumulate in the food chain. The top layer of the food chain, such as dolphins, will accumulate the largest and highest concentration of toxins. These toxins are mainly stored in fat. Within the organization. Dolphin lotion contains 40% fat, which will contain a lot of toxins. The first dolphins have absorbed a total of 10 years of toxins accumulated in their mothers because of breastfeeding. Because the immune system is still developing, the resistance is weak, and the dolphins become The biggest victim of toxins in the sea. After the toxins in the mother of the dolphins are transferred to her first baby by the emulsion, if she regenerates the second and third births, the survival opportunities for the next generation will be much greater.
distribution area
The Chinese white dolphins prefer to inhabit the estuary brackish waters in the subtropical waters, and are distributed in northern Australia, along the Indian Ocean coast, and along the Pacific coast of Southeast Asia. The Chinese white dolphins are mainly distributed in the southeastern coast of China. According to the literature, the northernmost reaches the Yangtze River estuary and extends southward to the estuary waters of Zhejiang, Fujian, Taiwan, Guangdong and Guangxi, and sometimes enters the river.
According to relevant survey data, there are two areas where Chinese white dolphins are concentrated in China. One is the Jiulong River Estuary in Xiamen and the other is in the Pearl River Estuary in Guangdong.
The Chinese white dolphins in the Pearl River Estuary are mainly distributed in the estuary of the Yangzhou, Wanshan Islands and southwestern Hong Kong waters. According to the survey data of the South China Sea Fisheries Research Institute from 1997 to 2000, the northern boundary of the dolphins distribution is in the waters of Shenzhen Airport, the southern boundary is in the area of ​​Dongao-Xiaoputai Island; the east side of Dasha Island, Shenzhen Bay, Longguzhou The waters of the northern part of Hong Kong's new airport and the coast of Lantau, the west side of Xiangzhou Bay and the sea off Macao, all have Chinese white dolphins distributed, with a distribution area of ​​not less than 1200km2. The dense area of ​​the white dolphin activity is mainly in the southeastern part of the Bohai Sea. Among them, the sighting rate of dolphins is higher around Neigu Island, Mayoushi to Lantau Island and Guishan Island. From the western waters between Qi'ao Island and Macao, The sighting rate of dolphins is low. The distribution situation is high in the east and low in the west, and the difference is significant.
In addition, the Chinese White Dolphins also have a distribution of finless porpoises along the Pearl River Estuary. The finless porpoise is a national secondary protected animal. The location of the finless porpoise is slightly souther than the Chinese white dolphins. It is often active near the Guishan Island and the waters south of Hong Kong. Its population size is small, and it appears in small groups of 2 to 5 heads.
The Bohai River estuary can become a dense area for the gathering and habitation of Chinese white dolphins. There are three main reasons.
1. The brackish water meets, the water quality is fertile, the water temperature and salinity are suitable for the survival activities of the white dolphin;
2. The Pearl River Estuary is rich in biology;
3. The water quality environment is relatively good and the pollution is light. Especially on the coast of Neiwan Island and the west side of Lantau Island, the natural coastline has not been developed and the water environment is quiet. It has become an ideal place for Chinese white dolphin activities.
On the evening of November 29, 2011, a dead Chinese white dolphin was found in the Shishi, Fujian, and Xiangzhi sea area. It is estimated to be more than 30 years old, weighing more than 300 pounds, female.
Population status
The current "family" of Chinese white dolphins is on the decline, and even on the verge of extinction. Since only one child is born every three years, the Chinese white dolphins have a low reproductive rate and a low survival rate, and the deterioration of the living environment is a serious threat to them. According to the monitoring of the China White Dolphin National Nature Reserve Administration in the Pearl River Estuary, as of 2011, there were only 802 white dolphins that survived, which is rarer than giant pandas. [2]
Facing the crisis
Reclamation and reclamation
Reclamation and reclamation are the most common methods for land reclamation on both sides of the Pearl River estuary. In the Pearl River Delta, where the piers are built, roads are built, roads are built, real estate is expanded or farmland is built, and aquaculture bases are built. Reclamation is not only private contracting, but also many of the actions of government departments.
The biggest harm is the destruction of the ecological environment of the coastal zone. The natural mangroves are destroyed, the beaches are eroded, the estuary waters are narrowed, the intertidal creatures and shallow sea fish have lost their homes, and various fish and shrimps The traditional natural spawning grounds and breeding grounds were destroyed in the roar of bulldozers.
As a result of land reclamation, the activity area of ​​the Chinese white dolphins has been narrowed, the number of feeding places has decreased, and the variety and quantity of food have become increasingly monotonous due to the decline of intertidal organisms.
blasting
The mountain blasting, island quarrying, mountain reclamation and underwater blasting, which are carried out simultaneously with land reclamation, often use heavy explosives to form a strong shock wave, which makes the mountain shake and the tsunami surge. Gravel splashes into the sea. In December 1993, many dolphins were killed in the blasting construction of Zhuhai City in Sanzao Island. From 1993 to 1995, during the construction of the new airport in Chek Lap Kok, Hong Kong, many white dolphins were injured.
Digging sand
The infrastructure project requires a large amount of sea sand. Every day, dozens of dredging vessels operate in the Pearl River Estuary. The dredging operation not only destroyed the seabed, but also seriously damaged the habitat of benthic organisms. The fish and shrimps were swallowed by a dredger, and the sea area became ridiculous. The original benthic and fish-shrimp breeding areas It no longer exists. While dredging, it also agitates the sediment to cause secondary pollution. The water body is very turbid, which affects the white dolphins unable to carry out various normal ecological and physiological activities. The Guangdong Provincial Government has ordered a ban on sand excavation on the coast, which is a policy guarantee for protecting the habitat of white dolphins in the future.
Overfishing in fisheries
This is also an important reason for the sharp decline of fishery resources in the Pearl River Estuary. Annual fishing boats in the Pearl River Estuary, to Panyu, Zhuhai, Dongguan,
There are many mobile fishing boats in Shenzhen and Hong Kong, as well as fishing boats from Taishan, Yangjiang, Chenghai and Raoping. The operation methods include single towing, double towing, ginseng, shrimp tow, spur, fixed, etc. The fishermen complained: "The day is dragging the night, the seabed is scraped off several layers of skin, the fish is more and more thin (small ), the yield is getting lower and lower." It can be seen that the destruction of fishery resources is serious.
Due to the fishing transition, the Pearl River Estuary has not been able to fish, and a large number of fishing boats have stopped and stopped. The cold fishing has made the fishermen's life difficult, the days of the white dolphin are not good, the disorderly placement of the gill net and the trawling accidentally increase the chance of injury to the white dolphin, and the illegal activities such as electricity, bombing and poisonous fish. It is the biggest threat to the survival of the white dolphins. The original fat estuary fishery attracted the white dolphins to rest and recuperate, but now the food of the white dolphins has become a problem. No fish can be licked, and food is not enough. If no more powerful measures are taken (such as the method of artificial reefs), the white dolphins can only migrate or die, and there is no other way out.
Ships frequent
The Pearl River Estuary is one of the busiest sea areas in China and even in the world. Hong Kong and Macao travel to and from Guangzhou and Hong Kong. There are also various types of vessels in Guangzhou and the Pearl River Delta, including ocean-going giant ships, large and small passenger ships, high-speed express ships, and various kinds. Cargo ships, fishing boats, tugboats, engineering work boats, oil tankers, etc., shuttle to and fro, making the entire Pearl River mouth very lively, but also make the white dolphins not peaceful. The survival of the white dolphin relies on its special echolocation system for message transmission and foraging, but the noisy ship mechanical noise interferes with the sound transmission of the dolphins, so that they cannot accurately judge the threat of the environment, and the serious ones are thus ruined. According to the fishermen, on the Hong Kong and Macao route north of Guishan Island, the white dolphins that were killed by the jet hydrofoil were sometimes seen.
Discharge of industrial and domestic sewage
The Pearl River Delta is an economically developed area. Thousands of factories upstream, especially paper mills, chemical plants, electroplating plants, printing and dyeing plants along the coast, are all industrial wastewater discharged into the Pearl River Estuary. It is undoubtedly a natural fishery and spawning ground in the Pearl River Estuary. The direct destruction has cut off the food source of the Chinese white dolphins. The white dolphins will instinctively avoid the migration of these poisonous and odorous wastewater. As the relevant departments have adopted various environmental protection measures, including the management measures for “standard discharge, total controlâ€, the environmental quality problems of the Pearl River Estuary have been alleviated, but the current organic nitrogen and oil water quality standards are still serious.
Pesticide pollution
The Pearl River Delta is a subtropical economic crop producing area. Various pesticides, herbicides and organochlorine pesticides are also a destructive factor for the fishery resources of the Pearl River Estuary. It is also a threat to the survival of white dolphins. According to reports, tissue analysis of individuals from the death of Chinese white dolphins found that the content of pesticide DDT and polychlorinated biphenyl (PCB) in the Chinese white dolphins in the Pearl River Estuary was higher than that in other parts of Asia. This phenomenon may be the result of the accumulation of white dolphins in the body through the food chain. These substances, when accumulated in the white dolphins, destroy their own reproductive and immune systems. Obviously, the pollution of pesticides on the survival of the Chinese white dolphins in the Pearl River Estuary cannot be ignored.
Oil pollution
Oil tankers have occurred in the collision and oil spill accidents in the Pearl River Estuary, especially the oil spill. The formation of large oil film on the sea surface has blocked the normal exchange of seawater and air, which is likely to cause water body oxygen deficiency, pollute the fish body and cause fish to die of oxygen deficiency. . For example, the "Donghai 209" and the "Smoke-burning 2" oil tanker that occurred on March 24, 1999 collided in the Bohai Sea, causing the tanker to sink, and more than 800 tons of heavy oil leaked, and the contaminated area reached 300km2. The 40km coastline in Zhuhai City is seriously polluted, causing great losses to coastal aquaculture farms and large mangroves. If the white dolphin encounters oil pollution, it must be exposed to oil during its floating breathing. When breathing, there is a possibility of inhaling oil into the lungs, and the consequences will inevitably endanger the survival and health of the white dolphin.
Waste dumping area
There are a number of waste dumping areas in the Pearl River Estuary, one of which is located on the east and west sides of Neiwan Island. In the southeast waters of Shazhou Island, there is also a silt dumping area designated by the Hong Kong Government. The designated dumping areas are mostly set by government departments. As for a large amount of civil waste, it is thrown into the rivers and finally drifted to the Pearl River Estuary. These wastes and sludges often contain a lot of heavy metals and toxic substances. It not only pollutes the seabed and water quality, but is sometimes poisoned by fish and various organisms and accumulates in the body, entering the white dolphins through the food chain.
Although the Chinese white dolphins have many adaptability to aquatic life, the inherent physiological characteristics of terrestrial mammals such as viviparous, lactating and lung respiration are also one of the factors leading to endangerment. In October, the time of pregnancy is long, the number of one child is small, and the long breastfeeding period makes some young children die. In addition, the dolphins that have entered the river are mostly difficult.
Protection action
Taiwan's Sun Yat-sen teacher with our SM2M dolphin voice recorder to record noise levels Taiwan waters of the Chinese white dolphin habitat.
This is a summary article published in the Journal of the Acoustics Society of America (a very authoritative magazine in the field of acoustics). The teacher at Sun Yat-sen University in Taiwan uses our SM2M to record the noise level of the white dolphins in Taiwan's waters.
Wei RC, Kuo LH, Wu JC, Chen CF, Analysis of ambient noise in the habitat of Indo-Pacific humpback dolphin (Sousa chinensis) in the West Coast of Taiwan. The Journal of the Acoustical Society of America [2013, 134 (5 ): 4116]
The links are as follows:
http://europepmc.org/abstract/MED/24181456
For your ordering convenience, choose from these top items within popular categories:
Applicators / Swabs
Aprons - Disposable
Bags / Kits
Bags / Wraps / Tubing
Bandages Gauze
Band-Aides
Bedpans & Urinals
Bibs
Blades / Scalpels - Disp
Blankets
Blood Collection needles
Blood Collection Tubes
Blood Tubing Sets
Bowls & Basins
Burn Care
Camera Drapes
Capes
Caps / Head Wear
Casting
Charts - Diagnostic
Chemistry & access
Chemotherapy
CholesterolMeter/Strip/Control
Circuits
Cleanup Kits / Bags
Collars
Conforming
Controls & Calibrators
Cotton
Debridement & Supplies
Defibrillator access
Diagnostic Thermal Paper
Dialyzers
Disinfectants Detergent Bleach
Dispensing Containers
Dressings
Drinking Fountains & access
Drug/Alcohol Tests
Ear / Utility / Air
ECG / EKG / EEG Paper
ECG / EKG / EEG Supplies
Elastic / Tubulars
Electro / Cryosurgery Supplies
Electrode-Diagnostic-Procedure
Emergency Bag & access
Endo Trach & Supplies
Environmental Safety
Exam Room Supplies
Extrication Tools
Eye Protection / Eye Wear
Face Masks
Fecal Occult Blood Tests
Feeding Tubes
Field Guides / Books / Videos
Filaments - Sensory
Fistula Needles
Footcare Management
Footwear
Forceps/Hemostat/Clamp Disp
Garments
Glass & Plastic Ware
Glove Access Glove Dispenser
Glove Access Liners
Glove Access MISC
Gloves Latex LP & PF Exam-Str
Gloves Latex LP Exam-NS
Gloves Latex LP Exam-Sterile
Gloves Latex LP Surg-Sterile
Gloves Latex PF Exam-NS
Gloves Latex PF Surg Sterile
Gloves Nitrile LP Exam-NS
Gloves Nitrile PF Exam-NS
Gloves Nitrile PF Exam-Str
Gloves NonLtx LF&PF Surg-Str
Gloves Vinyl Synth LP Exam-NS
Gloves Vinyl Synth PF Exam-NS
Gloves Vinyl/Synt LP Exam-Str
Gloves Vinyl/Synt PF Exam-Str
Glucose Meter-Strips-Controls
Gowns
Gowns / Aprons
H Pylori
Hazmat Identification
Head & Foot Wear
Hearing Protection
Hematology and access
Holster
Holter Supplies
Huber Needles
Ice Machines
Influenza
Instrument Care
Insulin Needles / Syringes
Irrigating Solutions
IV / Injection Training
IV Access
IV Catheters
IV Procedure Trays
IV Solutions
Jars / Tins / Boxes
Knee Braces & Supports
Lab Coats / Jackets / Smocks
Lab Supplies
Lancets
Linens - Disposable
Linens - Reusable
Manikins
Medical Publications
Medicated
Microbiology Testing & access
Microscope slides / Pipettes
Mono
Mouthguards
Mouthpieces
Nebulizers
Needles
Needles / Syringes
Orthotics / Shoe Inserts
Ostomy-Illeostomy-Supplies
Oxygen
Packs & Kits PU
Padding-Foam /Gel /Cast /Felt
Paste Bandages
Personal Care
Pillows / Cushion & Positioner
Pipettors / Pipettes & access
Post-Op Care
Pouches
Pregnancy
Probe Cover/Sheath - All Kinds
Protective Clothing
Racks
Radios & Communication
Reagents
Restraints
Resuscitation
Reusable Needles / Syringes
RSV
Scrubs
Self-Adherents
Sensi-disc
Sharps Bracket / Cabinet
Sharps Disposal
Shoe and Boot
Shoe Covers
Simulation Kits
Skin Punches - Disp
Soap - Hand Sanitizers
Sponges
Straps
Surg Supplies
Surgical Mesh
Suture Needles
Sutures / Supplies / Kits
Syringes
Test Tubes & access
Therapy Supplies
Thrombosis / Compression
Tongue Depressors
Tourniquets
Towels
Tray Covers
Trays...
Medical Items,Medical Disposables,Clinical Products
NOUVASANT GROUP LTD. , https://www.nouvasant.com