Better global water management for better environmental and economic benefits
Rivers that serve 80% of the world's population are threatened by agricultural runoff, pollution and invasive species, according to a new international study. 'Riverthreat' was funded in part by the EU's EVOLTREE ('Evolution of trees as drivers of terrestrial biodiversity') project, which received just over EUR 14 million under the 'Sustainable development, global change and ecosystems' Thematic area of the Sixth Framework Programme (FP6). The findings were recently published in the journal Nature.
Researchers, led by the City College (CCNY) of the City University of New York (CUNY) and the University of Wisconsin, studied the effects of a variety of environmental stressors on water systems. They found that in addition to threatening human lives, pollutants also endanger the biodiversity of 65% of the world's river habitats and put thousands of aquatic wildlife species at risk. The team produced a series of maps documenting these negative impacts using a computer-based framework.
'We can no longer look at human water security and biodiversity threats independently,' said Professor Charles J. Vörösmarty from CCNY, one of the authors of the study. He noted that the two needed to be linked, saying 'the systematic framework we've created allows us to look at the human and biodiversity domains on an equal playing field'. He and his team believe the framework 'offers a tool for prioritising policy and management responses to a global water crisis'.
'We've integrated maps of 23 different stressors and merged them into a single index,' explained Professor Peter McIntyre from the University of Wisconsin. 'In the past, policymakers and researchers have been plagued by dealing with one problem at a time. A richer and more meaningful picture emerges when all threats are considered simultaneously.'
The researchers found that the security of human water supplies were highly threatened in both developed and developing nations, but insisted that the expensive engineering schemes used by rich western countries trying to solve such problems were untenable for poorer nations, and called for a global, more economic approach to water security.
'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,' Professor Vörösmarty remarked. 'We can afford to do that in rich countries, but poor countries can't afford to do it.'
The team said causes of degradation in many of the developing world's most threatened rivers bore striking similarities to those in wealthy countries and suggested there were cost-effective solutions to these problems.
For example, Professor Vörösmarty argued it would be more cost effective to ensure that river systems are not impaired in the first place by better land use management, better irrigation techniques and greater emphasis on protecting ecosystems. Healthy ecosystems provide many valuable, and free, services to society by providing clean water, flood control, and food supplies.
One of the study's goals is to support international protocols that can be used for water system protection. The researchers believe an international approach is critical since more than 250 river basins cross international borders.
'It is absolutely essential to have information and tools that can be shared across nations,' stressed Professor Vörösmarty. 'Our knowledge of these systems is progressively worsening as nations fail to invest in basic monitoring. How can we craft protocols on biodiversity protection and human water security without good information?'
Researchers from Australia, France, Germany and Switzerland contributed to this study.