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Publications archive - Biodiversity

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Key departmental publications, e.g. annual reports, budget papers and program guidelines are available in our online archive.

Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time. It may contain references to activities or policies that have no current application. Many archived documents may link to web pages that have moved or no longer exist, or may refer to other documents that are no longer available.

Asia-Pacific Migratory Waterbird Conservation Strategy: 1996-2000

Wetlands International - Asia Pacific
International Waterfowl and Wetlands Research Bureau - Japan Committee (IWRB-J), 1996
ISBN 983 9663 18 6


Note: This publication has been superseded by Asia-Pacific Migratory Waterbird Conservation Strategy: 2001-2005

3. Overview of waterbird status and threats

3.1 Waterbirds in need of special action

It is important that the primary effort is aimed at maintaining the diversity of migratory waterbirds in a favourable conservation state. The conservation status of waterbirds across the Asia-Pacific region varies greatly, and there is little precise information on the sizes of most populations. From the information available, it appears that a few species and populations are on the increase, others are in decline, and others may be stable, but for the vast majority the situation is unknown.

Figure 1. Proportions of threatened migratory species in the Asia-Pacific region (See Annex 4 for details)

To promote conservation and maintain a high avian diversity, it is necessary to identify species and populations of special conservation interest. Special efforts should be focused on these "threatened species". Recent compilations of information have served to identify these species, although the list is not considered complete (Figure 1 and Annex 4).

3.2 Main threats to waterbirds

The Asia-Pacific region supports more than half the world's human population, and in recent years has achieved the highest economic growth rate in the world. The cost of high economic growth has also been the rapid, and often unsustainable, use of natural resources and degradation of the environment. Three main threats to the long-term conservation of migratory waterbirds are linked to this growth: habitat loss, habitat degradation and harvesting of waterbirds.

3.2.1 Habitat loss

The Asia-Pacific region encompasses a great diversity of habitats used by migratory waterbirds, ranging from the Siberian tundra to forests, rivers and estuaries, lakes and marshes, farm lands, rice fields, deserts, coastal marshes, sandy beaches, intertidal mudflats, coral reefs and atolls, and mangroves.

The loss of habitat through changes in land utilization practices is the most severe threat to the long-term conservation of waterbirds in the region. Drainage and land claim of wetlands continues to take place in most countries and territories, and has affected many waterbird habitats. This trend is especially significant in coastal regions of temperate and tropical Asia and Oceania, where human population density is high and there is considerable urbanization. The expansion of human activities, especially agriculture and aquaculture, has caused the decrease of natural wetlands and loss of habitat in the region. However, certain agricultural crops, such as rice, have created large areas of seasonally-useful habitat for some waterbirds. Deforestation across the region has also resulted in habitat loss for certain forest-dwelling waterbirds. In contrast to habitats loss in the temperate and tropical regions, there has been less impact in the high arctic

A more far-reaching consequence of industrialization is the increasing damage to the environment caused by acid rain. The main effects of acid rain are upon the habitat of migratory waterbirds breeding in the temperate regions of the north.

Coastal ecosystems, islands and atolls, with their mangroves, inter-tidal mudflats and coral reefs, are prone to changes in global sea levels. One of the main predicted impacts of "global warming" or "climate change" continues to be a rise in global sea levels. Increasing sea levels will adversely affect the present spatial distribution and dynamics of these coastal ecosystems and their component flora and fauna. Several species of migratory waterbird, especially, shorebirds depend on these habitats throughout their annual cycle (at breeding, staging and non-breeding sites) and it is likely that sea-level rise would have serious implications for their long-term conservation prospects.

3.2.2 Habitat degradation

In addition to direct loss of habitat, degradation of the environmental quality of habitats occurs because of over-exploitation of wetland resources (inland shell fisheries, mangroves, reeds, etc) and changes in the watersheds resulting from logging and mining, urban, rural and industrial developments. Degradation usually reduces the ability of the habitat to support a high density and diversity of birds. Pollution and eutrophication from industrial, agricultural and domestic operations create severe problems for inland and coastal wetlands. These contaminants affect waterbirds both directly and indirectly.

3.2.3 Harvesting of waterbirds

The collection of migratory waterbirds and their eggs for food and feathers is practised in several countries. Whilst in some countries hunting is strictly regulated by legislation, uncontrolled and illegal activities are still a major problem in many important migratory staging and non-breeding areas.