History of Hong Kong’s Deep Bay wetland including Mai Po Marshes to 1990

“If you look at satellite photos of the Pearl River delta, Deep Bay really shows up. There is nothing else like it.”

David Melville

Published in Asia Magazine (South China Morning Post), November 1990

An estuary shared by North-West Hong Kong and China’s Shenzhen Special Economic Zone is one of Asia’s top sites for wetland birds. Misleadingly called Deep Bay, the estuary is the winter home of about 40,000 waterfowl, and a major stopping-off point on migration routes linking Siberia and Australia, with perhaps 100.000 shore birds calling in each year.

Dalmatian Pelican among Deep Bay birds in 2010; the pelican is now locally extinct

It is also among the most threatened wetlands in Asia. Indeed, it seems that if you name a threat for wetlands, Deep Bay faces it. There is pollution from farms, factories and human sewage. In addition, there may be seepage from ash lagoons and – from next year – one of the world’s largest rubbish tips. Large-scale dredging is imminent, and may adversely affect water currents. And plans have been drawn up (but so far shelved) for airports and mud dumping.

But Deep Bay is not about to expire without a fight. Reserves have been established on both the Hong Kong and Shenzhen sides of the bay, the Hong Kong Government has introduced restrictions on developments, and a joint liaison group has been set up with the future of Deep Bay a major concern.

Mai Po Marshes

The better of the two reserves is at Mai Po Marshes, in Hong Kong. It is managed by the World Wide Fund for Nature Hong Kong, which is currently pressing the government to list Deep Bay under the Ramsar Convention on Wetlands of International Importance. The convention encourages management of wetlands for sustainable use. It does not guarantee protection but listing a site is supposedly a commitment to ensuring it will not be degraded. So far, the government has been reluctant to list Deep Bay under the convention, leading to fears that destructive development is a possibility.

David Melville, a conservation director of WWF Hong Kong, says there have been endless discussions of criteria for a Ramsar site, and several are used to demonstrate international importance. Deep Bay, as a site which annually holds more than one percent of the continental population of a migratory bird, qualifies with ease. Over one percent of each of four species – Saunders’ Gull, Dalmatian Pelican, Nordmann’s Greenshank and Black-faced Spoonbill – visit Deep Bay each year. The Black-faced Spoonbill is the rarest of these, with less than 300 known in the world. About 40 spend the winter in Deep Bay.

Deep Bay might also qualify as a good representative of a wetland type. The mud flats are backed by extensive mangroves, a habitat which has been largely destroyed in south China. There are reportedly no mangroves left along the coast to Hainan, where the most extensive tracts have been planted since the early 1980s. There is also a high diversity of marine life; 15 species were first discovered in the Mai Po area, and several of these are yet to be found anywhere else.

Newly established WWF Hong Kong focuses on Mai Po

Efforts to conserve the bay began in the mid 1970s, sparked by plans for a housing estate at Fairview Park, near Mai Po. This is the period, according to Melville, “when the rot set in – there has been a lot of new development since then. At the time, there was the rather naive belief that people living in Fairview Park would want to walk through Mai Po, and two members of the Hong Kong Bird Watching Society, Mike Webster and Fred Hechtel, petitioned the government to get some sort of conservation measures. Without their action, we may have lost Mai Po, which was declared a site of special scientific interest. This does not give legal protection, but increases the awareness of planners that a place is important.

“The land was effectively kept on hold until the WWF was formed, and was capable of running a managed reserve. Shortly after being founded in 1981, WWF Hong Kong realised that if it was to be successful in raising funds for conservation, it had to explain to the people of Hong Kong what conservation was all about. So WWF Hong Kong looked for a suitable project, and the only one of any importance which was feasible was a managed reserve at Mai Po.

“In 1982, a management plan was prepared by Steve Goodall, a consultant from the Wildfowl Trust from the UK, and approved in principle by the government.The Royal Hong Kong Jockey Club provided initial funds, and, in 1985, things started to happen on the ground.”

The reserve is on the southern edge of the bay, and includes large shrimp ponds with extensive reed beds. Helped by fundraising events involving the bird-watching society, WWF Hong Kong has bought several of the ponds, which have been landscaped to make them more attractive to wildlife.

There are hopes that the government will purchase the remaining land at Mai Po Marshes for the WWF. The larger reserve would help to attract more wildlife, as well as allow an increase in the number of human visitors. Last year, more than 25,000 people visited Mai Po. Most were school children on educational visits; others included bird-watchers from Europe, Japan and the United States, as well as conservationists from China learning about reserve management.

WWF Hong Kong’s work to protect and promote Mai Po has been crucial in increasing awareness of the value of the Deep Bay area. And, though there has been fudging over the Ramsar listing, the organisation’s efforts have helped stimulate the Hong Kong Government into action, especially the Environmental Protection Department. In 1988, the government commissioned a study on the Deep Bay environment. This was especially concerned with the cumulative impact of development around the bay, and recommended an action plan for integrated management of the area.

Threats including development and pollution

Several current and planned developments could threaten Deep Bay. A port with oil storage facilities is being established on the Chinese side of the mouth of the bay. Melville is also concerned there may be seepage from “one of the world’s largest rubbish tips”, which is to be built in Hong Kong just a few kilometres from the mud flats, as well as the potential for boron leeching out from power station ash lagoons.

But, it seems, neither of these would be as threatening as other, existing, sources of pollution. Livestock waste entering the bay from the Hong Kong side may soon be reduced because of controls, but the levels of organic pollution in parts of Deep Bay are already among the worst in Hong Kong, with human waste flowing, or oozing, in. Though sewage is treated, Melville is not sure how effective this is, and points out that the human population around the bay has increased dramatically in recent years. Industrial development also leads to pollution, and WWF finds information on the chemicals being released in Hong Kong difficult to obtain because of secrecy regarding factory operations.

On the positive side, a sewer which is to be built to serve a new town on the Hong Kong side should help reduce pollution in Deep Bay, as it will also carry effluent which currently enters the bay, and empty into deeper water to the south.

But, first, the infamous Yuen Long nullah is to be deepened and flushed out. This runs into Deep Bay, and is laden with organic and chemical waste. The faster flows will lead to poisonous mud washing into Deep Bay. Melville says: “The whole project. from our point of view, has been a disaster. We first heard about it in 1986, and advised the government the effects were likely to be severe.

“The Deep Bay review also said there were a lot of potential problems, and an environmental impact assessment was required. We made a legal objection over a year ago, as it seemed the engineers wanted to go ahead and were oblivious to the negative effect it might have on the bay. It is only in recent months that the government has started to assess the impact. A legal objection can be considered somewhat confrontational, but is the only recourse in a situation like this.”

Other, potentially far more damaging schemes have been considered. Airports seem a recurring favourite, largely because of the expanses of flat land without build-ings. In the 1950s, there were ideas for an airport across the mouth of Deep Bay, which would be transformed into a freshwater reservoir. Since then, both Hong Kong and Shenzhen have toyed with, but dropped, plans for airports.

Recently, a scheme for dumping mud in Deep Bay has been considered. Reclamation projects in Hong Kong can throw up large volumes of mud, which is currently dumped at sea. Storage lagoons in Deep Bay were considered as an alternative. The mud would settle in the lagoons, which would be built ever higher, and eventually – though not part of the plan – the stabilised lagoons should be ideal for building on. So far, this has been stopped at the assessment stage, as have ideas for extracting sand from Deep Bay

With reclamation schemes appearing unlikely in the near future, it appears pollution is the main threat to Deep Bay. In Hong Kong, the new south-bound sewer, controls on livestock farming and industrial pollution should lead to improvements.

But pollution controls in Shenzhen are far more lax. Some reports suggest dirty Hong Kong factories will simply move across the border. Anti-pollution laws are often more strict there but they are rarely enforced.

Problems such as this will be covered in meetings of the recently established Hong Kong-Guangdong Environmental Protection Liaison Group. Rob Law, the assistant director of the Environmental Protection Department, is hopeful that the group can work to reduce Deep Bay pollution: “Cynics might say, ‘Fine; committees’, but I can say we are very serious in our intentions and, from what I’ve seen, the Chinese are, too. We will do all we can to save Deep Bay,” he said.

Nevertheless, fears remain that the effective policy in Shenzhen is one of unfettered economic growth. One observer has commented: “We might find the creek where Yuen Long nullahs now empty becomes the cleanest part of Deep Bay, while on the other side there might be a black nullah. With dyeing, textiles and electronics industries moving to China, the bay could be poisoned so much that it is a threat to the birds using it. They might take in toxic pollutants here during winter, fly north to breed in summer and have problems, like eggs with thin shells or no shells.”

There is nothing else like it

With all the problems confronting Deep Bay, it might be tempting to conclude that conservation efforts would be better employed elsewhere. But Deep Bay is special.

Melville says: “If you look at satellite photos of the Pearl River delta, Deep Bay really shows up. There is nothing else like it.”

And in spite of all the adverse development, the numbers of birds have tended to increase in recent years. This is partly due to a ban on hunting on the Hong Kong side since 1980, and reflects loss of habitat in China

Deep Bay is a key staging area for migrating birds, a “pit stop” where they can rest and refuel before heading on. Shorebirds [waders] are the most obvious of the migrants, with up to 10,000 crowding on to Mai Po when the tide is high during April. Some are on journeys between beaches in south Australia and breeding grounds on Arctic tundra. Great Reed Warblers are less evident. mostly hidden from view among Mai Po reed beds, yet for them, too, this is an important place for putting on the weight needed for a successful journey.

Throughout the winter, there are tens of thousands of birds in Deep Bay. When time and tide are right, the bird spectacle is among the finest in Asia, with tight packs of gulls and shorebirds, ducks lining the tide line, and flights of cormorants.

The birds do not have a ready alternative to Deep Bay. Its loss would mean the endangered species would move so much closer to extinction, while already dwindling populations of even the more common species would be further reduced. The unique crab and other marine life would disappear. And Hong Kong and Shenzhen would lose a priceless resource for people, a slice of “wilderness” in an ever more urban environment.

Leave a Reply

Your email address will not be published. Required fields are marked *