Freshwater shortages threaten the living world

Posted: 21 March 2006

The growing shortage of freshwater is likely to trigger increased environmental damage over the next 15 years, according to a widely researched report on the world's waters to coincide with World Water Day (March 22).

Falls in river flows, rising saltiness of estuaries, loss of fish and aquatic plant species and reductions in sediments to the coast are expected to rise in many areas of the globe by 2020.

These in turn will intensify farmland losses, food insecurity and damage to fisheries along with rises in malnutrition and disease.

Overall agriculture ranks highest as the key concern on the freshwater front among the 1,500 experts involved in the final report of the Global International Waters Assessment (GIWA).

Woman carrying water, Ethiopia. Photo: WHO/P. Virot
Woman carrying water, Ethiopia. Photo: WHO/P. Virot
Woman carrying water in a jar near Alem Kitmama North East of Addis-Ababa, Ethiopia. Credit: © WHO/P. Virot

Ignorance on aquifers

"Globally, there has been an increased demand for agricultural products and a trend towards more water-intensive food such as meat rather than vegetables and fruits rather than cereals".

Knowledge gaps are also to blame, with many developing countries operating in the dark on the size of their water resource, and the precise patterns of supply and demand.

"Aquifers represent the largest information gap, which is an increasingly significant hindrance for effective water management given the growingdependence on groundwater," says the report released in advance of World Water Day.

Market failures are also highlighted as important contributors to damage inboth freshwaters and coastal zones.

"Most production inputs are under-priced compared with their full social and environmental costs", says the report, citing the under-pricing of water, subsidies for pesticides and fishing and incentives forinfrastructure, like dams and water transfer schemes.

Too much fishing

The damage to international waters from overfishing and destructive fishingmethods is also underlined.

The report points to the excessive catches fueled by $20 billion a year fishing subsidies, poor enforcement of fishing laws and destructivepractices like blast fishing on coral reefs.

"The investment of one dollar (in blast fishing) can generate an immediate 200-fold return for local fishermen but leaves a devastated reef that takes 50 years to recover," says the report.

The report recommends ecosystem service payments as one way of better valuing the goods and services provided by natural features like coralreefs and wetlands.

For example, it argues that wetlands in Mexico would be less vulnerable if landowners are paid for the waste water treatment provided by these natural pollution filters.

Climate's key role

Climate change is viewed as the overarching issue in the report, with specific concerns for fisheries and marine organisms.

It estimates that climate variability is the key controlling factor in fishing yields for about half of the world's large marine ecosystems.

These include the East and West Greenland shelfs; the Benguela Current off Southwest Africa, the Canary Current off Northwest Africa and the Humboldt Current off the West coast of South America.

Thus climate change may have important impacts on yields in these sensitive regions.

These are among the findings from the GIWA implemented by the United Nations Environment Programme (UNEP) with funding from the GlobalEnvironment Facility (GEF) and national governments, especially Nordic ones. It is a unique endeavour, bringing together scientists and experts from social and economic backgrounds.

Their final report, Challenges to International Waters: Regional Assessments in a Global Perspective, was formally launched on World Water Day, together with a string of recommendations to reverse the damage anddeclines.

Klaus Toepfer, UNEP's Executive Director, said that one clear messages emerging from the study was that "our collective failure to value the goods and services provided by international waters, and to narrowly price the benefits in terms of the few rather than the many, is impoverishing us all".

"I sincerely believe that overcoming poverty and meeting the internationally agreed Millennium Development Goals requires us to lookharder at the way we manage the natural world. Demands that we give greater value to the natural capital of forests and grasslands up to our freshwaters and coastal habitats," he added.

GIWA has been looking at five priority areas including freshwater shortages, pollution and overfishing. It finds cause for serious concern in all areas and that many of the problems are expected to "increase in severity by2020".

Among the positive findings is an expectation that the overfishing problem will improve "in over 20 per cent of the GIWA regions/sub-systems" over the next two decades as a result of more sustainable management practices.

Freshwater shortages

The GIWA experts predict that only around six of the areas studied, including the Murray Darling Basin in Australia, the Mekong River region and the Russian Arctic region, are expected to see impacts decline.

Massive amounts of water are usedto irrigate cropland in California© Inga Spence/Holt Studios International
Massive amounts of water are usedto irrigate cropland in California© Inga Spence/Holt Studios International
Massive amounts of water are usedto irrigate cropland in California© Inga Spence/Holt Studios International
It says that rising demand by irrigated agriculture now accounts for 70 per cent of freshwater withdrawls with only 30 per cent of this returned to the environment.This compares with industry and households which return up to 90 per cent of the water used.

Almost a third of the regional teams pointed to the impact on water flows from dams, river diversions and water transfers. These can obstruct migration routes and reduce spawning habitats. Dams on the Volga River, for example, have reduced the spawning habitat of Caspian sturgeon.

They can also be highly inefficient. More than 90 per cent of the water in Namibia's Eastern National Water Carrier canal is lost through evaporation.

The report also cites the loss of ecosystems in the Aral and Dead seas and impacts on the Volta River Basin and in Lake Chad as a result of water diversions.

The Berg River estuary in South Africa has suffered high salinity levels which are affecting birds, fish and bottom living invertebrates, as a result of upstream water withdrawls.

Similar problems have been experienced in the Ganges-Brahmaputra River system where more than 30 dams, barrages and river diversions upstream have reduced dry season river flows in Bangladesh by up to 60 per cent.

The construction of the Akosombo Dam on the Volta River in Ghana has increased the proportion of children infected with the parasitic disease schistosomiasis from five per cent to 90 per cent.

Pollution problems

Transboundary pollution ranks as the top issue in a quarter of all the international waters studied. And by 2020, the environmental impacts of pollution are predicted to increase in severity in over three quarters of the GIWA regions.

Suspended solids, largely as a result of deforestation and agriculture, severely affect coral reefs, seagrasses and river habitats ina fifth of the areas studied. These include the Caribbean Sea, the Brazil Current, East African Rift Valley lakes and all regions of Southeast Asia.

Eutrophication - triggering oxygen deficiencies as a result of fertilized agricultural run-off, sewage discharges and air pollution - is present in lakes, rivers and many semi-enclosed seas in Europe and Central Asia and sub-Saharan Africa. It is on the rise in Northeast Asia and the Gulf of Mexico.

Dumping of solid wastes is a priority issue in many rivers and coastal areas of sub-Saharan Africa, in Small Island Developing States, parts of the Indonesian seas and stretches of the Rio Grande in the Gulf of Mexico.

Mining effluent pouring into the Amazon© Julio Etchart/ Reportage / Still Pictures
Mining effluent pouring into the Amazon© Julio Etchart/ Reportage / Still Pictures
Mining effluent pouring into the Amazon© Julio Etchart/ Reportage / Still Pictures
Chemical pollution is an issue as hot spots including Central America, West Africa, South and Southeast Asia as well as on the River Jordan, Aral Sea and the Arctic rim.

Oil spills cause severe problems in the Caribbean Sea, Niger Basin and the Benguela Current in Southwest Africa.

Overfishing threats

Overfishing and other threats to aquatic living resources is ranked as the top priority in over a fifth of the GIWA areas studied with 60 per cent of the teams citing over exploitation as severe.

Three quarters of the regions say destructive fishing practices are harming habitats and fish dependent communities.

Destructive fishing includes bottom trawling, blast or bomb fishing, fishing with poisons such as cyanide, muro-ami nets, and other locallyemployed techniques.

Blast fishing in Indonesia is expected to cost that country at least US $3 billion over the next 20 years. A sustainable hook and line fishery could generate net benefits of $320 million over the same period.

Many farmed fish operations are unsustainable. Outbreaks of disease at shrimp farms in the Humboldt Current, West coast of South America, have cost $600 million annually, not including economic damage to wild stocks.

The report is optimistic that at least in some areas new policies and management actions are beginning to be introduced that promise to improve the situation.

Community management of fisheries, certification of fish and the extension of marine parks also promise improvements. Catches near the Bamburi Marine Park in Kenya, for example, have increased more than twofold since it came into existence.

Protecting habitats

Climate change, alteration of river flows, coastal developments, pollution and other factors are adding to habitat modification and changes in freshwater and coastal living communities.

In the Guinea current region, the expansion of Accra, Ghana, has led to the clearing of over half of the mangroves and significant areas of marshland.

In the Philippines, 60 per cent to 80 per cent of mangroves have been cleared for port developments.

Land reclamation projects in the Pacific Islands has led to more than half of the region's mangroves being lost or severely degraded.

In the Volta River Basin, degradation of mangroves has changed the fish species composition by 70 per cent since 1969. It has led to the collapse of the shrimp and Jack mackerel fishery and a down turn in the freshwater clam industry.

Source: UNEP

The full report can be downloaded at the Global International Waters Assessment website.