What aspect does the Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 primarily focus on preventing?

The Nonindigenous Aquatic Nuisance Prevention and Control Act of 1990 is primarily focused on preventing the introduction and spread of nonindigenous aquatic species, which are often transported through ballast water. Ballast water is taken on by ships to maintain stability and is typically discharged in new environments, potentially introducing invasive species that can disrupt local ecosystems, outcompete native species, and cause significant ecological and economic harm. By regulating ballast water management practices and promoting prevention measures, the act aims to protect aquatic environments from the dangers posed by these foreign species. This focus is critical for maintaining biodiversity and the health of aquatic ecosystems.