Ballast water discharges by ships can have a negative impact on the

marine environment Marine habitats are habitats that support marine life. Marine life depends in some way on the saltwater that is in the sea (the term ''marine'' comes from the Latin ''mare'', meaning sea or ocean). A habitat is an ecological or environmental ...

. The discharge of ballast water and sediments by ships is governed globally under the

Ballast Water Management Convention The International Convention for the Control and Management of Ships' Ballast Water and Sediments (Ballast Water Management Convention or BWM Convention) is a 2004 international maritime treaty which requires signatory flag states to ensure that ...

, since its entry into force in September 2017. It is also controlled through national regulations, which may be separate from the Convention, such as in the United States. 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

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1 ...

es, and

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

. These materials often include non-native, nuisance, exotic species that can cause extensive ecological and economic damage to aquatic ecosystems, along with serious human health issues including death.

Problematic species

There are hundreds of organisms carried in ballast water that cause problematic ecological effects outside of their natural range. The

International Maritime Organization The International Maritime Organization (IMO, French: ''Organisation maritime internationale'') is a specialised agency of the United Nations responsible for regulating shipping. The IMO was established following agreement at a UN conference ...

(IMO) lists the ten most unwanted species as: *Cholera ''

Vibrio cholerae ''Vibrio cholerae'' is a species of Gram-negative, facultative anaerobe and comma-shaped bacteria. The bacteria naturally live in brackish or saltwater where they attach themselves easily to the chitin-containing shells of crabs, shrimps, and oth ...

'' (various strains) *Cladoceran Water Flea ''

Cercopagis pengoi ''Cercopagis pengoi'', or the fishhook waterflea, is a species of planktonic cladoceran crustaceans that is native in the brackish fringes of the Black Sea and the Caspian Sea. In recent decades it has spread as an invasive species to some freshw ...

'' *Mitten Crab ''

Eriocheir sinensis The Chinese mitten crab ('; , "big sluice crab"), also known as the Shanghai hairy crab (, p ''Shànghǎi máoxiè''), is a medium-sized burrowing crab that is named for its furry claws, which resemble mittens. It is native to rive ...

'' *Toxic algae (red/brown/green tides) (various species) *Round Goby ''

Neogobius melanostomus The round goby (''Neogobius melanostomus'') is a fish. Defined as a euryhaline bottom-dwelling goby of the family Gobiidae, it is native to Central Eurasia, including the Black Sea and the Caspian Sea. Round gobies have established large non-na ...

'' *North American Comb Jelly ''

Mnemiopsis leidyi ''Mnemiopsis leidyi'', the warty comb jelly or sea walnut, is a species of tentaculate ctenophore (comb jelly). It is native to western Atlantic coastal waters, but has become established as an invasive species in European and western Asian reg ...

'' *North Pacific Seastar ''

Asterias amurensis ''Asterias amurensis'', also known as the Northern Pacific seastar and Japanese common starfish, is a seastar found in shallow seas and estuary, estuaries, native to the coasts of northern China, Korea, far eastern Russia, Japan, Alaska, the Aleu ...

'' *Zebra Mussel ''

Dreissena polymorpha The zebra mussel (''Dreissena polymorpha'') is a small freshwater mussel. The species originates from the lakes of southern Russia and Ukraine, but has been accidentally Introduced species, introduced to numerous other areas and has become an inv ...

'' *Asian Kelp ''

Undaria pinnatifida Wakame ''(Undaria pinnatifida)'' is a species of kelp native to cold, temperate coasts of the northwest Pacific Ocean. As an edible seaweed, it has a subtly sweet, but distinctive and strong flavour and texture. It is most often served in soups ...

'' *European Green Crab '' Carcinus maenas'' Other problematic species include: *Spiny Water Flea '' Bythotrephes longimanus''

Ballast water issues by country

New Zealand

The ballast tanks in New Zealand carry animals and plants that kill ecosystems. Ballast tanks are only used in cargo ships there. Ballast water is controlled under the

Biosecurity Act 1993 Biosecurity Act 1993 is an Act of Parliament in New Zealand. The Act is a restatement and reform of the laws relating to pests and other unwanted organisms. It was a world first. In the Act an "unwanted organism" is defined to be one that "is ...

Peru

A form of

cholera Cholera is an infection of the small intestine by some strains of the bacterium ''Vibrio cholerae''. Symptoms may range from none, to mild, to severe. The classic symptom is large amounts of watery diarrhea that lasts a few days. Vomiting and ...

, ''Vibrio cholerae'', previously reported only in

Bangladesh Bangladesh (}, ), officially the People's Republic of Bangladesh, is a country in South Asia. It is the eighth-most populous country in the world, with a population exceeding 165 million people in an area of . Bangladesh is among the mos ...

apparently arrived via ballast water in

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

in 1991, killing more than 10,000 people over the following three years.

United States

The zebra mussel, which is native to the

Caspian Caspian can refer to: *The Caspian Sea *The Caspian Depression, surrounding the northern part of the Caspian Sea *The Caspians, the ancient people living near the Caspian Sea *Caspian languages, collection of languages and dialects of Caspian peopl ...

and

Black Sea The Black Sea is a marginal mediterranean sea of the Atlantic Ocean lying between Europe and Asia, east of the Balkans, south of the East European Plain, west of the Caucasus, and north of Anatolia. It is bounded by Bulgaria, Georgia, Roma ...

s, arrived in

Lake St. Clair Lake St. Clair (french: Lac Sainte-Claire) is a freshwater lake that lies between the Canadian province of Ontario and the U.S. state of Michigan. It was named in 1679 by French Catholic explorers after Saint Clare of Assisi, on whose feast day ...

in the ballast water of a transatlantic freighter in 1988. Within 10 years it had spread to all of the five neighbouring

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...

. The economic cost of this introduction has been estimated by the U.S. Fish and Wildlife Service at about $5 billion. Ballast water discharges are believed to be the leading source of invasive species in U.S. marine waters, thus posing public health and environmental risks, as well as significant economic cost to industries such as water and power utilities, commercial and recreational fisheries, agriculture, and tourism. Studies suggest that the economic cost just from introduction of pest mollusks (zebra mussels, the

Asian clam ''Corbicula fluminea'' is a species of freshwater clam native to eastern Asia which has become a successful invasive species throughout North America, South America, and Europe. ''Corbicula fluminea'' is commonly known in the west as the Asian cl ...

, and others) to U.S. aquatic ecosystems is more than $6 billion per year.

Congress A congress is a formal meeting of the representatives of different countries, constituent states, organizations, trade unions, political parties, or other groups. The term originated in Late Middle English to denote an encounter (meeting of a ...

passed the National Invasive Species Act in 1996 in order to regulate ballast water discharges. The Coast Guard issued ballast water regulations in 2012. Under the authority of the

Clean Water Act The Clean Water Act (CWA) is the primary federal law in the United States governing water pollution. Its objective is to restore and maintain the chemical, physical, and biological integrity of the nation's waters; recognizing the responsibiliti ...

, the

Environmental Protection Agency A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...

(EPA) published its latest ''Vessel General Permit'' in 2013. The permit sets numeric ballast water discharge limits for commercial vessels in length or greater. EPA issued a separate permit for smaller commercial vessels in 2014.

Singapore

Among 818 ports in the Pacific region, Singapore alone accounts for an estimated of 26 percent of cross-region (long range) species exchange. Via targeted ballast management on Singapore and a few other "influential" ports, cross-region species exchange to/from the Pacific region can be combinatorially reduced.

IMO convention

To react to the growing concerns about environmental impact of ballast water discharge, the

(IMO) adopted in 2004 the "'' International Convention for the Control and Management of Ships' Ballast Water and Sediments''" to control the environmental damage from ballast water. The Convention will require all ships to implement a "Ballast water management plan" including a ballast water record book and carrying out ballast water management procedures to a given standard. Guidelines are given for additional measures then the guidelines. The goals of the convention are to minimise damage to the environment by: * Minimise the uptake of organisms during ballasting. * Minimising the uptake of sediments during ballasting. * Ballast water exchange while at sea (the ship should be minimum 200 nautical miles from shore with a depth of minimum 200 metres and can use the flow through or sequential method). At least 95 percent of the total ballast water should be exchanged. * Treatment of the ballast water by chemical or mechanical influences (UV-radiation, filter, deoxygenation, cavitation, ozone…) Control measures include: * ''International Ballast Water Management Certificate'' * Ballast water management plan * Ballast water record book The IMO convention was ratified by enough countries and entered into force on September 8, 2017.

References

* Buck, Eugene H.(2012)
"Ballast Water Management to Combat Invasive Species."
´

U.S. Congressional Research Service The Congressional Research Service (CRS) is a public policy research institute of the United States Congress. Operating within the Library of Congress, it works primarily and directly for members of Congress and their committees and staff on a co ...

. Report No. RL32344.

External links

GloBallast partnership
( IMO)
International Convention for the Control and Management of Ships' Ballast Water and Sediments (BWM)
( IMO) {{Wastewater Ocean pollution Environmental impact of shipping de:Ballastwasser-Übereinkommen no:Ballastvann