Research on and protection of the Chinese White Dolphin in Hong Kong

1. Research on and protection of the Chinese White Dolphin in Hong Kong TANG WING LUN (6B) (27)

2. INTRODUCTION • Species name is Indo-Pacific Humpback dolphin • (Sousa Chinensis), or we call as Chinese White Dolphin • First recorded in the Pearl River Estuary by Explorer Peter Mundy • in 1937 • belong to Kingdom Animalia –Class Mammalia-Order Cetacea-family • Delphinidae • At birth - about 100 cm in length • Maximum - about 270 cm and 250 kg • Up to 40 years old in other parts of the world • The oldest in Hong Kong was 33 years old

3. Majority of dolphin groups dive less than 1 minute, range from 10 to • 277 seconds • A dolphin group may contain up to 23 members and the mean is 4 • Social structure among them is very fluid and group composition • changes frequently • Reaching maturity at their age about 10-11,they will get • marry and have their baby. • Having calves throughout the year, with slight peaks in spring • and summer

4. GLOBAL AND LOCAL DISTRIBUTION • they love globally, from mid or north of Australia, South China, Indonesia, India to South Africa. They live in tropic or temperate costal regions • There are roughly 7-8 isolated • populations of Chinese white dolphins • along the coast of China • In H.K.,they appear in the western • waters,including outer Deep Bay, • north, south and east Lantau, and • west Lamma, but never in the • eastern water

5. Their distribution in Hong Kong also shows • seasonal variation • At least 1400  dolphins found in the Pearl River Estuary and • Hong Kong waters

6. BOBY COLOUR • Chinese White Dolphins have 3 different colors which is based on • their age. • Newborn dolphins are grey in colour • Juvenile dolphins are pure pink in colour • Adult dolphins are pink in colour • Results from flushing of blood to the body surface • but not from red pigments in the skin • Related to thermoregulation

7. HABITAT AND ACTIVITY • Dolphins or whales live in deep water regions, but Chinese White • Dolphins live in some shallow water regions • When they are resting or playing, normally they will assembly in • regions where near to beaches • Behaviors: breaching, spy-hopping, porpoising, surfacing and • driving

8. Eating habits • Chinese White Dolphins have between 116 to 152 tooth • Dolphins hunt when there is need,, and consume as much as 10 kg of • fish per day, such as lion-head fish (Collichthys lucida), various • croakers (Johnius spp) and anchovies (Thryssa spp) are the • typical types of fish • One of the most interesting feeding behaviours is that they will • follow fishing trawlers in order to catch those fish that escape from • the nets

9. Finless porpoise • Fishers called the porpoises ‘sea pig’,probably because • they look chubby. • is another species of marine mammal that lives in Hong Kong waters. • recognized as relatives of the Chinese White dolphin, but the • differences between the two are quite distinctive. • Belong in the family Phocoenidae • They are light grey in colour when • they are young and when they get • older they turn a deep grey.

10. GLOBAL AND LOCAL DISTRIBUTION • Range from northern Japan to the • Persian Gulf, but apparently • excluding most of Philippines • be found in the adjacent • Chinese waters to the east • and south of Hong Kong • the Chinese white dolphins and • finless porpoises never occur • together in the same area.

11. Porpoises Dolphins Appearance Smaller, mostly < 2m Larger Dorsal Fin Smaller or even absent More triangular in shape Larger, always present Rostrum or Beak Absent Prominent Teeth Spaded-shaped Conical Behaviour Shy Not approach boats Not exhibit aerial behaviour Very active Exhibit lots of aerial behaviour, such as breaching, spy hopping, wake-riding and bow-riding

12. ESTIMATE THE NUMBER OF DOLPHINS • Two researchers go out on boat look for dolphins along fixed routes (i.e. transects) in different areas and keep track of the time, positions and other environmental conditions at the same time • Record information on group size, perpendicular distance between the vessel and the dolphins, etc • Enter data collected from boat surveys into a specialized computer program called DISTANCE line transect boat survey

13. photo-identification • Take photographs on unique features of dolphin's back and • dorsal fin, such as nicks, scars and distinctive colour • patterns • Identify each dolphin according to the features, which could • provide information on individual home range and abundance Square Fin (NL24) Ringo (NL11) Slash (NL139) Curly (NL111)

14. Will the dolphins disappear very soon? General perception that the local population of Chinese White Dolphins might be extinct in a few years is not true and is not supported by scientific evidence Dolphin population in the Pearl River Estuary (including Hong Kong) contains about 1400 animals. This number indicates the dolphin population is still viable in the region

15. HUMAN IMPACTS • Habitat Loss and Disturbance • Pollution • Fishery By-catch • Vessel traffic • Depletion of Food Resources http://www.chinese-white-dolphin.net/game.html

16. Habitat Loss and Disturbance • If Construction activities( eg.reclamation ) occurring within the • dolphins’core habitat, then the reclamation would result in a • permanent loss of their habitat. • For instance, Chek Lap Kok airport platform in North Lantau • the soil or sand will increase the turbidity. Finally, dolphins no • longer can live in there. • dolphins might have experienced disturbance and stress • during piling and have temporarily moved out of the adjacent area • during the construction

17. Pollution • the sewage could be a potential source of pathogenic bacteria, fungi • and viruses. Chinese White Dolphins are vulnerable to a number of • pathogens which can be transmitted via human sewage wastes. • other environmental contaminants, such as heavy metals and organic • compounds, can be another potential long-term threat to the local • dolphin population

18. Fishery By-catch • Deliberate capture of dolphins does not appear • to be a significant threat in Hong Kong. • They were however very likely • the result of incidental catches. • the dolphins will be hurt during • catching by the fish-net

19. Vessel traffic • In the photo-identification catalogue, there are some individuals • which show unmistakable evidence of propeller cuts on the body, • apparently resulting from previous encounters with vessel collisions • vessel traffic also generate noise that can interfere with • communication of dolphins and make the correct decision and action • vessel collision, together with incidental catch by • fishermen were found to be two of the most significant human- • related mortality factors.

20. Depletion of Food Resources • feeding habit studies found that there was an overlap in prey of • dolphins and targets of fishing vessels, competition exists between • fishermen and dolphins for the same fisheries resources. • There is some recent evidence suggesting that the fisheries • resources in Hong Kong have declined. This would affect not • only the fishermen, but also dolphins • Both of them will surely suffer if the there is a continual decline in • fisheries resources of the area

21. CONSERVATION PLAN Aim: to enable the Chinese White Dolphins to continue to use waters of Hong Kong SAR as a portion of their population range and to enhance the continued survival of this dolphin population inhabiting the Pearl River Estuary. • management • public education • research • cross-boundary co-operation

22. Management---Improve the General Marine Environmental Conditions • Major efforts should be made to clean-up local waters and improve • water quality • TheStrategic Sewage Disposal Scheme (SSDS) is intended to • provide a sewage collection, treatment and disposal system in stages • to improve water quality in Victoria Harbour. (Stage Icompletion by • late 2001 ) • Government is planning to disinfect all effluent discharging into • North Lantau waters, which is the most important dolphin habitat in • Hong Kong. (disinfection facilities will be providedat Siu Ho Wan • Sewage Treatment Plant by 2004.)

23. Management--- Minimize or Avoid Impacts of Coastal Development • if need to have construction near the habitat of the dolphins,the • proponent would be required to conduct an ecological assessment with • special reference to dolphins. • to ensure that the residual impact to dolphins would be kept within • acceptable levels. • the Environmental Impact Assessment (EIA) team established within • Agriculture, Fisheries and Conservation Department (AFCD) would • examine the project to ensure that the impact assessment on • dolphins is properly done

24. Management---Designate More Marine Protected Areas • Statutory designation of the protected core area, followed by its • active and effective management, would go a long way to help • maintain the long-term viability of the species. • AFCD is considering the way forward with a view to designating • Southwest Lantau as a Marine Park for the benefit of the dolphins. • During the interim, Southwest Lantau as a Site of Special Scientific • Interest (SSSI).

25. Management---Ensure Protected Areas are Properly Managed • Physical and biological monitoring programmes were established • to keep track of the conditions, both the physical parameters • and biological characteristics within Marine Park. • . • Vessels travelling in the Marine Park must observe a speed • limit of 10 knots • implementations of measures to re-build the local fish stock will • therefore enhance the long-term availability of prey species to the • dolphins

26. Public Education ---Promote Community Involvement and Awareness • to arouse public interest and awareness of dolphin protection • AFCD has produced leaflets, posters, Video CD, CD-ROM and • bookmarks on Chinese White Dolphins. • Exhibition panels have been displayed in some of our • visitor/education centres. • More information will also be made available • in the AFCD homepage,such that any person • interested may access the information easily • through the Internet

27. Research---Monitor Trends in Abundance of Chinese White Dolphins • Continual monitoring of abundance would provide a useful indicator of • the success of the conservation measures • The Multi-disciplinary Research Programme on Indo-Pacific Hump- • back Dolphin Population (MRP) study has provided useful baseline • information for future monitoring • Collection of stranded dolphin carcasses and detailed • necropsies provide information on the causes of death, and • samples for life history studies

28. Cross-Boundary Co-operation ---Advisory Body • The Working Group established in 1995 • Members of the Working Group include scientists, government representatives, Green Group members, and fishermen leaders • to seek advice and guidance from Working Group members for • continuous and effective review of the Conservation Programme for • the Chinese White Dolphin

29. Cross-Boundary Co-operation ---with Neighbouring Administrations • A Study Group for the Conservation of Chinese White Dolphin was • established in 1997 under the Technical Sub-Group of the Hong • Kong – Guangdong Environmental Protection Liaison Group (EPLG). • Hong Kong and Xiamen governments to share experience in the • management of protected areas for dolphins and to exchange • knowledge and information on this important species.

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