Freshwater Shortages, Engineering of River Flows, Pollution and Overfishing Highlighted in Final Global International Waters Assessment
21 March 2006 - Freshwater shortages are likely to trigger increased environmental damage over the next 15 years, according to an international report of the world’s waters.
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).
“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 growing dependence on groundwater," says the report released in advance of World Water Day 22 March.
Market failures are also highlighted as important contributors to damage in both 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 for infrastructure, like dams and water transfer schemes.
The damage to international waters from overfishing and destructive fishing methods is also underlined.
The report points to the excessive catches fueled by $20 billion a year fishing subsidies, poor enforcement of fishing laws and destructive practices 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 coral reefs 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 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 Global Environment Facility (GEF) and national governments, especially Nordic ones.
The assessment, a unique endeavour, brought together not only scientists but experts from social and economic backgrounds.
They have been evaluating current and future trends in the freshwater and coastal waters of some 66 transboundary water areas, mainly linked with developing countries.
Their final report, Challenges to International Waters: Regional Assessments in a Global Perspective, is formally launched today, complete with a string of forward looking recommendations to reverse the damage and declines.
Klaus Toepfer, UNEP’s Executive Director, said: “There are many important messages emerging from this pioneering study. One that rings loud and clear is the economic one -- 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 look harder 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.
Mr Toepfer thanked Gotthilf Hempel, Professor Emeritus for Biological Oceanography at the University of Kiel, and Science Advisor to the Senate of Bremen, Germany, for his great contribution.
"Professor Hempel, our GIWA Ambassador, played an important role in the preparation of the final report. We are indebted to him for his wisdom, experience and knowledge in guiding the final chapter of this seminal work," he added.
GIWA has been looking at five priority areas including freshwater shortages, pollution and overfishing.
The report concludes that there is cause for serious concern in all areas and that many of the problems are expected to “increase in severity by 2020”.
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.
The GIWA experts predict that the environmental impacts of freshwater shortages will mostly increase or remain the same over the next 15 years.
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.
The report notes 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 modification of water flows as a severe consequence of shortages.
Modifications include the building of dams, river diversions, water transfers, and other structures designed to supply water and energy.
Such engineering works can obstruct migration routes and reduce spawning habitats. The report cites the impact of dams on the Volga River which 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 loss and change in water flow as a result of engineering works can have important knock-on effects.
The report cites the loss of ecosystems in the Aral and Dead seas and impacts on the Volta River Basin and in Lake Chad.
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.
Transboundary pollution ranks as the top issue in a quarter of all the international waters studied and a further third classed it as their second most serious concern.
By 2020, the environmental impacts of pollution “are predicted to increase in severity in over three quarters of the GIWA regions/sub-regions, making this the most negative future outlook for any of the GIWA concerns,” says the report.
Suspended solids, increasing mainly as a result of deforestation and agriculture, severely affect coral reefs, seagrasses and river habitats in an estimated one 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 globally, parts of the Indonesian seas and stretches of the Rio Grande in the Gulf of Mexico.
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.
Impact of oil spills was assessed as severe in the Caribbean Sea, Niger Basin and the Benguela Current in Southwest Africa.
Overfishing and Other 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 locally employed techniques.
Blast fishing in Indonesia is expected to cost that country at least USD three 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.
For example, catches near the Bamburi Marine Park in Kenya have increased more than twofold since it came into existence.
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.
GIWA, was a United Nations Environment Programme (UNEP)-led and Global Environment Facility (GEF)-funded programme, with Kalmar University, Sweden as the main executing agency that hosted the GIWA Core Team and Co-ordination Office. All GIWA reports are available in print and at www.unep.org/dewa or www.giwa.net/publications
The embargoed press release will be available in French and Spanish later this week.
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UNEP News Release 2006/15