Conserving the quality of available water is a high priority world-wide. There are many countries whose water supply is reaching dangerous levels of contamination. For example, the longest river in China, the Yangtze, is less than 5 years from death if nothing changes. The statements below are possible effects on the environment if the Yangtze dies, which one is a positive effect on the environment? A) The loss of biodiversity in the area could permanently damage the ecosystems in area. B) Loss of this river could stress the other water supplies in surrounding areas causing a domino effect. C) The Yangtze empties into the Sea of Shanghai, which may lead to serious problems in this important body of water. D) Since the pollution in the water is high in organic material, it will eventually decompose and make the area more fertile.

As the contaminating materials are mainly the organic wastes, microorganisms present in the river water will decompose the matter and due to this the breakdown products will be released there in the river. The products that will be formed as a result of breakdown of organic wastes include carbon dioxide, energy, water, plant nutrients and resynthesized organic carbon compounds. The nutrients present in the breakdown products will further make the area more fertile for the vegetation in that particular area.