Ballast water discharge can introduce aquatic nuisance species. Which option best reflects this statement?

• A. Ballast water discharge can introduce aquatic nuisance species
• B. Ballast water discharge can release infectious bacteria
• C. Ballast water discharge decreases salinity of the deep ocean
• D. Ballast water discharge increases oxygen concentration

Answer: (A)

Ballast water discharges carry organisms from one region to another. When discharged in a different ecosystem, those organisms can establish themselves and become aquatic nuisance species, disrupting native communities, fisheries, and biodiversity. That real-world risk is exactly what the statement highlights. The other options aren’t the main concern: while ballast water can contain bacteria, the notable issue emphasized here is the introduction of non-native aquatic species; ballast water doesn’t meaningfully reduce deep-ocean salinity or increase oxygen concentration.