A disadvantage of which energy is its negative impact on aquatic ecosystems?

• A. Water
• B. Solar
• C. Wind
• D. Biomass

Answer: (A)

Hydroelectric energy, which relies on flowing water to generate power, can have the most direct and widespread negative effects on aquatic ecosystems. Dams and reservoirs alter natural river flows, block fish migration routes, trap sediments that downstream habitats depend on, and change water temperature and oxygen levels. These changes can degrade spawning grounds, reduce biodiversity, and disrupt food webs. While other energy sources like solar or wind have relatively limited direct impacts on aquatic life, hydro projects inherently interact with water bodies and their ecosystems, making this a primary disadvantage when considering aquatic health.