Ballast water discharge and the environment

Ballast water discharges by ships can have a negative impact on the marine environment. Cruise ships, large tankers, and bulk cargo carriers use a huge amount of ballast water, which is often taken on in the coastal waters in one region after ships discharge wastewater or unload cargo, and discharged at the next port of call, wherever more cargo is loaded. Ballast water discharge typically contains a variety of biological materials, including pla... more

Ballast water discharges by ships can have a negative impact on the marine environment. Cruise ships, large tankers, and bulk cargo carriers use a huge amount of ballast water, which is often taken on in the coastal waters in one region after ships discharge wastewater or unload cargo, and discharged at the next port of call, wherever more cargo is loaded. Ballast water discharge typically contains a variety of biological materials, including plants, animals, viruses, and bacteria. These materials often include non-native, nuisance, exotic species that can cause extensive ecological and economic damage to aquatic ecosystems. There are hundreds of organisms carried in ballast water that cause problematic ecological effects outside of their natural range. The International Maritime Organization list the ten most unwanted species as: A form of cholera, Vibrio cholerae, previously reported only in Bangladesh apparently arrived via ballast water in Peru in 1991, killing more than 10,000... less