Slideshow

Freshwater dolphins and porpoises are found in the major river systems around the world including the Amazon and Orinoco in South America, the Ganges and Indus in India and Pakistan, the Yangtze in China and the Mekong in Laos and Cambodia. They feed on fish, crustaceans and molluscs, seasonally following shoals as they migrate along the river systems and frequent biological hotspots and deepwater pools in tropical rivers according to the season. They require good quality water as does the ecosystem within which they live, so their presence can be a good indicator of the health and productivity of the river.

Traditionally, river communities have also relied on the quality of the river water in order to live healthy lives and be able to benefit from its natural resources. However, many of these major river systems are either threatened with or have become heavily populated and over exploited as a consequence of our demands for freshwater resources. As this demand grows, the fragile ecosystems associated with the rivers and the communities that depend on them, are being destroyed.

Demands for freshwater resources have resulted in over fishing and the use of indiscriminate methods such as gillnetting, electro-fishing and dynamiting which have reduced important fish stocks to near collapse and hugely increased the numbers of incidental mortalities of dolphins and porpoises. Intensive floodplain farming, heavy boat traffic, riverside developments and heavy industry have caused heavy pollution, reduced the natural quality of the water and destroyed natural habitats. Water construction projects such as damming of tributaries and construction of barrages and levees have restricted or prevented both the fishes and dolphins ability to move along their previous ranges to important feeding and breeding grounds. This has meant the catastrophic decline of some fish species.

Whilst changes to the World's major river systems have been ongoing for many years, through increasing human populations and the development of industrialized economies, the demand for freshwater resources has increased alarmingly over the last few decades in many developing countries with huge environmental impact. This has occurred particularly in the countries in which freshwater dolphins and porpoises are found and has resulted in rapid unchecked riverside developments and alarming declines in dolphin and porpoise populations across the World. The activities of the last few decades can be seen as a chilling indicator of the future integrity of the freshwater systems in which they are found.

In China, the recent economic boom is putting unsustainable pressure on its freshwater ecosystems. As a result of changes affecting the countries major river system, the Yangtze, the Baiji is now the World's most endangered cetacean. If China does not take measures to reduce these pressures and manage its resources more effectively, it will run the risk of destroying its freshwater ecosystems completely, losing the Baiji to extinction and leaving its people facing a freshwater crisis. The plight of the Baiji and the finless porpoise in the Yangtze can be seen as an indicator of what the future might be.