Question

10 multiple choice 1 point
what is the biggest environmental cost of hydroelectric power?
fish and other animals dying due swimming to close to the turbines.
free - running rivers and their surrounding ecosystems being destroyed.
increased flooding downstream which can damage homes.
decreases in the number of species, and species diversity in the new lake.

Explanation:

To determine the biggest environmental cost of hydroelectric power, we analyze each option:

• The first option (fish dying near turbines) is a local impact, not the biggest.
• Building hydroelectric dams destroys free - running rivers and their surrounding ecosystems (like habitats for many species, river - dependent plants, etc.). This is a large - scale, fundamental change to the ecosystem.
• Increased flooding downstream is usually managed or not the primary environmental cost compared to ecosystem destruction.
• Decreases in species in the new lake are a result of the broader ecosystem destruction of the river system, so the destruction of free - running rivers and their ecosystems is more fundamental.

Answer:

B. Free - running rivers and their surrounding ecosystems being destroyed. (Note: Assuming the second option is labeled as B. If the original labeling is different, adjust the label according to the actual option numbering in the question. Here we assume the second option is the correct one and label it as B for the multiple - choice format.)