Conserving the quality of available water is a high priority world-wide. there are many countries where the 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. how could the loss of this river have a negative impact not only the environment in china but across the region?

a) the pollution is high in organic material so it will make the area more fertile.

b) the death of the organisms in this river will open up niches for other organisms to replace.

c) since the yangtze empties into the sea of shanghai the pollution will travel and have effects on surrounding countries.

d) the loss of such a river is so minor in the ecosystems of the area, the impact will be low and not a danger to surrounding areas.