Failure to protect and invest in nature has left the world’s rivers in crisis, threatening the water supply of more than five billion people according to a new study. Pollution, dam building, agricultural runoff, conversion of wetlands, and water-works engineering have severely impacting global river systems, the first- ever health assessment of the planet’s riverine ecosystems reported in Nature last week.
‘What made our jaws drop is that some of the highest threat levels in the world are in the United States and Europe,’ says Peter McIntyre, a co-author of the report who is a zoologist at the University of Wisconsin-Madison in the U.S.
‘Our study reveals, that on average, the richer the country the greater the threat to river systems,’ McIntyre told IPS.
Expensive water-works engineering to control freshwater quality and quantity in rich countries decimate rivers’ natural abilities to control and clean water the Nature study found. River systems provide an estimated six to seven trillion dollars in services to humanity every year, but the hundreds of billions of dollars spent on engineering systems impairs those services for short-term gain, says co-author Charles Vörösmarty of the City University of New York, an expert on global water resources.
‘We need to take another approach, to join hands with nature and work together,’ Vörösmarty said in an interview. ‘If we do humanity will get a far better payback in the future.’
Rivers are the arteries of the planet, linking continents through coastal zones to the ocean. More than 120,000 species of plants and animals make up the world’s riverine ecosystems that provide the multi-trillion dollar services humanity relies upon – however up to 20,000 are at risk of extinction Vörösmarty says.
An international team examined data sets on 23 factors that impact rivers around the world and created state-of-the-art computer models to integrate all of the information to paint the first ever global picture of the health of river systems. More than 65 percent of the world’s rivers are in trouble and this finding is very ‘conservative’ since there was not enough data to assess impacts of climate change, pharmaceutical compounds, mining wastes and massive inter-basin water transfers like the Colorado River in the western U.S.
Where rivers are least at risk are where human populations are smallest. Rivers in arctic regions and relatively inaccessible areas of the tropics appear to be in the best health, according to the findings.
In an unrelated study more than 80 percent of male bass fish exhibited female traits such as egg production because of a ‘toxic stew’ of pollutants in the Potomac River that flows through Washington, DC scientists reported last week. Similar findings have been made in many U.S. rivers.
‘In the industrialised world, we tend to compromise our surface waters and then try to fix problems by throwing trillions of dollars at the issues. We can afford to do that in rich countries, but poor countries can’t afford to do it,’ says Vörösmarty.
In Vörösmarty’s study the bitter pill for the developed world is that their huge investments in engineering water systems is in reality a kind of mismanagement. ‘It’s a maladaptive approach that creates vulnerabilities,’ he says.
Protecting watersheds, for example, can reduce the costs of drinking water treatment, preserve floodplains for flood protection, and enhance rural livelihoods. In the 1980s New York City determined it was far cheaper to protect and restore the source of its water supply – the Catskill/Delaware forests and wetlands – than spend six to eight billion dollars on a water treatment plant. ‘The benefits were very clear and the City saved billions of dollars,’ says Vörösmarty.
However this well-documented and highly successful strategy has not been emulated by many other cities including those in China or India where engineering expertise is highly prized and huge engineering works are a matter of national pride. Water management costs will skyrocket if developing countries emulate the approach of developed nations, Vörösmarty says. One of China’s major waterways, the Yellow River, no longer reaches the sea many days of the year and five percent of China’s rivers can no longer support fish.
It is better to invest in sustaining existing ecosystems than destroying them and attempting to engineer solutions, says Vörösmarty. ‘There needs to be a dialogue in China about the implications of engineering the water supply. It can work in the short term but takes a lot of energy and stresses river ecosystems that will eventually collapse.’
According to McIntyre, Latin American cities are doing better, and are protecting the water catchment areas. ‘Much of this is sparked by local brewery companies that have a vested interest in protecting clean, natural water.’
The study stresses prevention of problems and the long-term benefits of prevention and protection. Restoration of natural systems after they are destroyed or damaged is expensive and difficult. Of some 37,000 river and stream restoration projects in the U.S., few have in fact been restored despite a billion-dollar investment, says Vörösmarty. ‘We don’t realise what we’re doing when we screw up river systems, nor do we know how to fix them.
by Stephen Leahy (brooklin, canada)Tuesday, October 05, 2010
Inter Press Service
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Original source: Inter Press Service