Wetland Park Ecosystem & Environment in Hong Kong
                                                                                   [ In Chinese 中文 ]

The Northwest in Hong Kong

Our Mission:
Mission of the Hong Kong Wetland Park is to foster public awareness, knowledge and understanding of the inherent values of wetlands throughout the East Asian region and beyond, and to marshal public support and action for their conservation.

Our Objectives :
The following six objectives of the Hong Kong Wetland Park are of equal importance:

• To demonstrate the diversity of Hong Kong’s wetland ecosystem and highlight the need to conserve them;
  
• To create a visitor attraction of international status, catering both for the general public and visitors, and also for those with special interest in wildlife and ecology;
  
• To provide an attraction which will diversify the range of visitor experience in Hong Kong for visitors from aboard;
  To serve the recreational needs of the residents of the adjoining urban areas in the Northwest New Territories;
  
• To provide a facility that will both complement and supplement those offered at the Mai Po Marshes Nature Reserve;
  
• To provide opportunities for education and public awareness.

Mai Po

      The wetlands around the Mai Po Marshes and Inner Deep Bay in the northwestern corner of Hong Kong, have been known as a haven for migratory birds for many decades.

      Mai Po was not recognized as any form of protected area until 1976, when it was designated a Site of Special Scientific Interest. In 1983, WWF HK began to take active management of the Reserve for environmental education and conservation. In 1995, 1,500 ha of wetlands around Mai Po and Inner Deep Bay were formally designated a Wetland of International Importance under the Ramsar Convention.

      In addition to the birds, the Reserve has many other features of importance. The heart of the reserve is made up of 24 traditionally operated shrimp ponds (locally called gei wai), which are now the only such ponds in Hong Kong, and possibly in southern China. This unique system of shrimp production is increasingly seen as an example of the sustainable use of a wetland because shrimp production relies on the natural productivity of Deep Bay. The ponds are stocked by flushing in the naturally occurring young shrimps from Deep Bay, which then feed on detritus and plankton inside the ponds.

      The stand of inter-tidal mangroves fringing Mai Po and Deep Bay is the sixth largest in China, and the reedbed stands are one of the largest in Guangdong Province.

            Education and Public Awareness (EPA) plays a very important role at Mai Po. Up to 40,000 people visit Mai Po annually, with about 10,000 being primary and secondary school students who join one of the 400 specially guided school visits organised by WWF HK on weekdays. Neither the students nor the schools have to pay for this visit since the visits are purchased by the Hong Kong SAR Government Education Department.

            The Mai Po Nature Reserve is a restricted area. Entrance without prior permission from the related Hong Kong SAR Government authorities as well as WWF HK is strictly prohibited and may lead to your arrest and possible prosecution by Hong Kong SAR government officials.

            In terms of wildlife, the wetlands in and around the Mai Po Nature Reserve are probably most famous for its birds. Some 72% of all the bird species recorded in Hong Kong have been found at Mai Po. The Reserve also holds internationally important numbers of certain bird species, some of which are highly endangered.

View of Part of the Inner Deep Bay Ramsar Site with the Mai Po Marshes in the Background.		Aerial view of Fish ponds in the Northwest New Territories.		Fish Pond flooding in the Northwest New Territories.

BIRDS

            Every year, an estimated two to three million waterbirds, e.g. gulls, ducks, herons and shorebirds, migrate from their breeding grounds in northern China, Mongolia and Siberia, to their wintering grounds in southeast Asia and Australasia. Along their migration route, these birds depend on a number of staging posts where they can rest, feed and build up their energy reserves again before they begin the next stage of their long journey. The wetlands around the Mai Po and Inner Deep Bay Ramsar Site are one such site. In winter, up to 68,000 birds winter in these wetlands before flying back north in spring to their breeding grounds. During the spring and autumn migration periods, the site is used by an estimated 20,000 - 30,000 shorebirds.

      The importance of the Mai Po and Inner Deep Bay wetlands for birds has been known since the 1940's. Presently, over 340 species of birds have been recorded from these wetlands with 23 of these listed as being threatened (Click here to see the Table of Bird).

      Of these threatened species, more than 1% of the world population of Saunders' Gulls Larus saundersi and the Spotted Greenshank Tringa guttifer occur at Mai Po and Inner Deep Bay whilst for the Black-faced Spoonbill, some 25% of the world population winters at the site!

      In 1979, the Hong Kong Birdwatching Society began counts on the number of waterbirds wintering in and around the wetlands of Mai Po and Inner Deep Bay. From the first count in 1979, the numbers have increased from 12,830 (January 1979) to 68,000 (January 1997). Since then, however, the numbers have dropped and have stabilized at around 54,000. This decline is probably due to increasing pollution in Deep Bay, which affects the amount of food (e.g. crabs and mudskippers) available for the birds when they arrive.

            Research has only recently begun on mammals in Hong Kong and as such, new species are still being found. For example, the Javan Mongoose Herpestes javanicus was first recorded in Hong Kong at Mai Po in 1989.

      Other mammals recorded from Mai Po and Inner Deep Bay include the Eurasian Otter Lutra lutra chinensis,  Pangolin Manis pentadactyla, Chinese Leopard Cat Felis bengalensis, Crab-eating Mongoose Herpestes urva, Seven-banded Civet Viverricula indica and various Muridae, e.g. Bandicoot Rat Bandicota indica, Soricidae, e.g. House Shrew Crocidura murinus and bats such as the Pipistrellus abramus.

      Although the Chinese White Dolphin Sousa chinensis has previously been recorded up the Shenzhen River as far as Lok Ma Chau, its presence in Shenzhen Bay is now doubtful due to heavy boat traffic and pollution.

            In recent years, studies by students and enthusiasts have found some interesting information on the importance of Mai Po for invertebrates. For example, over 20 species of invertebrates have been discovered at Mai Po which are new to science. This includes a new species of crab (Parasesarma maipoensis) and two moths (Schrankia bilineata and Thalassodes maipoensis).

Some 400 species of invertebrates alone have been recorded from the reedbeds at Mai Po, including an endangered species of dragonfly (Mortonagrion hirosei).

            The habitats at Mai Po are also important. The mangrove forests at Mai Po together with those in the other parts of Deep Bay cover an area of some 400 ha and are the sixth largest protected stand remaining in China. The 45 ha of reedbeds at Mai Po are probably one of the largest (if not the largest) remaining in Guangdong Province. The 240 ha of gei wai is one of the largest areas of traditionally operated shrimp ponds left in southern China, and are seen as an example of how wetlands can be managed sustainably, for the benefit of the local community and for the environment.

Gei Wai		Fish Pond

BIRD MIGRATION

      Every year, there is an estimated two to three million birds that migrate back and forth from their summer breeding grounds in Siberia and northeastern China, and their wintering grounds as far south as Australia. Along their migration route, these waterbirds have to rely on a number of staging posts where they can rest and feed (refuel), as they cannot fly non-stop on their annual journey which may involve a round trip of 33,000 km! The wetlands in and around the Mai Po and Inner Deep Bay Ramsar Site are one such important staging post.

      Each winter, tens of thousands of waterbirds arrive from their northern breeding grounds to spend the winter around the Deep Bay wetlands. This includes 25% of the world population of the globally endangered Black-faced Spoonbill, and significant numbers of equally threatened species, such as the Saunders' Gull and Dalmatian Pelican.

            In Spring and Autumn, some 20,000 to 30,000 shorebirds stop over in Deep Bay whilst on migration to their northern breeding grounds, or to their southerly wintering ground respectively. Each bird may stay for about two to three weeks during which time, they may be able to double their body weight, and gain enough energy for the next part of their strenuous journey. These shorebirds include species such as the threatened Spoon-billed Sandpiper, Spotted Greenshank and Asiatic Dowitcher. At low tide, these shorebirds would be busy feeding on worms, snails and other small invertebrates on the extensive mudflats. At high tide however, they will fly into the Reserve to roost and wait until low tide again. On a typical high tide in Spring, there may be up to 10,000 shorebirds roosting in one of the Mai Po gei wai whose water level would be lowered at this time to allow these birds to come and roost.

      Mai Po also supports summer visitors such as the Yellow Bittern, which nests in the reedbeds that are the largest remaining in Hong Kong.

            Since 1966, volunteers have been conducting research on the migration of birds through Mai Po. These birds are caught and marked with individually numbered metal leg rings before they are released again. Some tens of thousands of birds have been marked at Mai Po in this way and a number have been re-caught abroad. Conversely, birds ringed abroad have been re-caught at Mai Po. This information allows us a greater understanding of the routes used by these migratory birds, and the bodily (physiological) changes and stresses that these birds go through in undertaking these long migrations.

      The weight data of Curlew Sandpiper Calidris ferruginea caught in autumn when they are migrating south to their wintering sites, show that some individuals carry sufficient fuel reserves (fat and protein) to possibly allow them to fly non-stop from Hong Kong to northwest Australia, a distance of about 4,750 km! In spring, however, when the birds are moving north, they carry sufficient reserves to take them only to northeastern China.

      In addition to being a refuelling stop during migration, some waders also remain during the autumn for the post-breeding moult. This is a physiologically demanding time when good food supplies are needed to promote new feather growth. Moulting may take several months and so a dependable food supply is required, as well as a suitable high tide roosting site.

      With WWF Hong Kong's management of the Mai Po Nature Reserve, an increasing number of waders are remaining to moult in Deep Bay. This is probably due to the provision of high-tide roosting sites in the Reserve, at a time of year when such sites are uncommon around the Bay.

      Studies on wader feeding ecology during their migration stopover at Mai Po are still at an early stage.

      In order to conserve these migratory birds, especially the shorebirds, there needs to be co-operation in protecting the wetlands used by these birds in the different countries along their migration route. In the East Asia - Australasian region, this will include countries as far apart as the Commonwealth of Independent States (Russia) and Australia, and many of the 57 countries in-between. As a result in 1996, an agreement was reached by countries along the flyway to co-operate and conserve the migratory waterbirds and the wetlands habitats that they use. In order to achieve this aim, a Migratory Waterbird Conservation Committee for the East Asia - Australasian region was established. One of the commitments, which countries that are participating in this agreement have to agree to, is to designate wetlands of importance for these migratory waterbirds. The result will be a chain of protected wetlands for these birds from their northern breeding areas to their southern wintering sites.

GEI WAI

             In Asia, people living in coastal areas have many hundreds of years of experience producing shrimps using ponds located adjacent to bays or estuaries. In Hong Kong, knowledge of how to do this did not arrive until the mid-1940's, when a wave of immigrants from China came into the Hong Kong SAR. These ponds were known as gei wai (literally meaning a pond enclosed by a bund) and were mainly for shrimp production but fish, oysters, algae and brackish water sedges were also harvested.

      Each of the Mai Po gei wai covers an area of approximately 10 ha and are now recognised as good examples of how coastal wetlands can be managed sustainably, i.e. so that they can be of benefit to local communities, with minimal adverse impact to the environment. This is because traditional gei wai shrimp production relies on the natural productivity in the adjacent bay. At Mai Po, the ponds are stocked by flushing in young shrimps from Deep Bay in autumn, and the shrimps feed on naturally occurring organic matter, e.g. dead mangrove leaves, on the bottom of the pond. As a result, fishermen protected the stands of mangroves inside the pond as a source of food for the shrimps and fish. The shrimp of main commercial importance is Metapenaeus ensis (gei wai shrimp) but fish, such as Mugil cephalus (Grey mullet) are also present.

      Shrimp harvesting takes place from the end of April until October or November after which, the gei wai are completely drained in turn for harvesting the remaining fish inside. At this time, up to 1,600 wintering birds, such as herons, egrets and the endangered Black-faced Spoonbill Platalea minor, may be attracted into a single gei wai. There, they feed on the non-commercial fish and shrimps trapped in the pools of water at the bottom of the pond. After about seven days as the food in the pond becomes depleted, these birds would then move onto the next gei wai that was being drained down and where food is more readily available. At this time, Otters Lutra lutra may also be attracted to these ponds as evidenced by records of their footprints by the pools of water.

            There are large areas of vegetation within the gei wai, principally mangroves, reedbeds and sedges (F: Cyperaceae). There is a rich benthic invertebrate fauna under the mangrove forests and in summer, several bird species nest in the mangroves trees. In 1994, over 500 pairs of herons and egrets nested in one gei wai mangrove stand.

      The 46 ha of reedbeds present in the Mai Po gei wai are probably one of the largest remaining stands in Guangdong Province, and is a rich feeding habitat for migratory birds, e.g. certain warblers in Spring and Autumn. Nearly 400 species of invertebrates have been recorded in these reedbeds, with approximately four being previously undescribed to science.

      Six species of sedges have been recorded in the gei wai three of which, have not been recorded elsewhere in Hong Kong. The grass Ruppia maritima ('Wigeon grass') has been found in the gei wai - the first record for Hong Kong since 1905!

      Due to land-use changes around Mai Po over the past 50 years, the only gei wai now left in Hong Kong are those at the Mai Po Nature Reserve, and they cover an area of 240 ha.

      Every Summer, during the shrimp harvesting season, WWF Hong Kong organises specially guided tours to allow the public an opportunity to see how gei wai shrimps are harvested and to learn about this unique form of land-use, which is part of Hong Kong's traditional coastal heritage.

RAMSAR SITE

             Count 6 March 1995 as a very special date for Mai Po and the Inner Deep Bay area. After years of lobbying by WWF HK and conservations both locally and overseas, and even the government-appointed Town Planning Board, the Hong Kong Government decided to designate an area of about 1,500 hectares in Mai Po and Inner Deep Bay as a 'Wetland of International Importance' under the Ramsar Convention. Along with the announcement of the designation, there was also a proposal to spend a sum of about $423 million over five years for necessary land clearance, establishment of education/visitor centers and conservation management.

Boardwalk for visitors at the Kushiro Marsh Ramsar Site, Japan.		River transport in the Sunderbans Site, Bay of Bengal

      An appropriate analogy to this Ramsar Site designation is the recognition of a scholar awarded a Nobel prize. Aiming at conserving and promoting the wise use of wetlands, the Ramsar Convention is an international treaty adopted at Ramsar, Iran in 1971. Following ratification by the U.K. in 1976, the Convention was extended to Hong Kong in 1979. China became a signatory in 1992.

A view of the freshwater marsh at Kushiro.		A view of the wetland in the Sunderbans.		The extensive mangroves at the Dongzaigang Ramsar Site, Hainan Island

Count 6 March 1995 as a very special date for Mai Po and the Inner Deep Bay area. After years of lobbying by WWF HK and conservationists both locally and overseas, and even the government-appointed Town Planning Board, the Hong Kong Government decided to designate an area of about 1,500 hectares in Mai Po and Inner Deep Bay as a 'Wetland of International Importance' under the Ramsar Convention. Along with the announcement of the designation, there was also a proposal to spend a sum of about $423 million over five years for necessary land clearance, establishment of education/visitor centers and conservation management.

Sunset over the Deep Bay wetlands.

            Each of the signatory countries to the Ramsar Convention has to designate at least one internationally important wetland in their country following a set of criteria. Currently, China has 21 Ramsar Sites (including Poyang Lake, Jiangxi Province; Dongting Lake, Hunan Province; Dongzaigang Nature Reserve, Hainan Province; Niaodao, Qinghai Province; Xianghai Nature Reserve, Jilin Province; Zhalong Marshes, Heilongjiang Province; Mai Po and Inner Deep Bay, Hong Kong SAR) (see map below).

Xianghai Nature Reserve Zhalong Marshes Niaodao Dongting Lake Poyang Lake Dongzaigang Nature Reserve Mai Po and Inner Deep Bay

      Mai Po and Inner Deep Bay were formally designated as a Ramsar Site on 5 September 1995 after years of lobbying by WWF HK. Below is a table showing how Mai Po meets the listing criteria:

Criteria of a Ramsar Site

How Mai Po meets the criteria

            Apart from caring for wetlands, which have been designated Ramsar Sites, each signatory country also has to try to conserve other wetlands in their country. Under Article 3 of the Convention, governments are obliged to "..include wetland conservation considerations within their national land-use planning. They are required to formulate and implement this planning so as to promote, as far as possible, the "wise use of wetlands in their territory".

In order to implement the "wise use" concept, governments are urged to develop National Wetland Policies in consultation with the local people. Governments should also set up a National Wetland Committee to coordinate decisions on wetland use. Under the 'wise use' concept, human activity can be allowed in a Ramsar site, e.g. for fish farming, low intensity recreation etc., as long as the use is sustainable.

The Mai Po and Inner Deep Bay wetlands are managed by the Ramsar Management Authority, chaired by the Agriculture, Fisheries and Conservation Department (AFCD) to ensure the wetlands are managed under the wise use principle. WWF Hong Kong has been charged with managing the core area that we possess in Mai Po.

Egrets over the Mai Po wetland

      Designation of the Mai Po and Inner Deep Bay Ramsar Site, in effect, provides an additional area of countryside in Hong Kong, which can be managed for education and recreation, as is being done at WWF Hong Kong's Mai Po Nature Reserve. In addition, the current land-use, e.g. fish pond farming in certain areas can be retained so that local people can continue to benefit from the area.

      Ramsar designation for the Mai Po and Inner Deep Bay wetlands provides an exciting opportunity for conserving the largest remaining wetland in Hong Kong, which can be managed for the benefit of the people of Hong Kong, as an area where education, recreation, farming and conservation can be integrated.

Critically Endangered Siberian Crane at Mai Po

      A Siberian Crane was discovered at Mai Po in the morning on 11 December 2002. This is the first time that this critically endangered species has been recorded in Hong Kong.

      There are about 2,500-3,000 Siberian Cranes in the world and most spend the winter in the Yangtze Valley, some 800km to the north of Hong Kong. 'The recent surge of the winter monsoon may have brought the bird to Mai Po' said Dr Lew Young, WWF Hong Kong Mai Po Reserve Manager.

      Cranes migrate south from their breeding grounds in Russia in family groups and the young birds usually remain with their parents for most of the winter. The bird at Mai Po is a juvenile but so far there have been no sightings of any adults.