Alien invaders in ballast water - new Convention to be adopted at IMO

International Conference on Ballast Water Management: 9-14 February 2004

A new international convention to prevent the potentially devastating effects of the spread of harmful aquatic organisms carried by ships' ballast water is set to be adopted at an international conference to be held from 9 to13 February 2004 at the London Headquarters of the International Maritime Organization (IMO), the United Nations agency responsible for the safety and security of shipping and the prevention of marine pollution from ships.

The proposed new instrument is being developed on the basis of a two-tier approach.

Tier 1 includes requirements that would apply to all ships, including mandatory requirements for a Ballast Water and Sediments Management Plan, a Ballast Water Record Book and a requirement that new ships carry out ballast water management procedures to a given standard. Existing ships would be required to do the same, but after a phase-in period.

Tier 2 gives Parties the option to take additional measures before ships would be allowed to enter their ports. Such additional measures are subject to criteria set in the draft convention and to IMO guidelines yet to be developed, and may also include additional controls applicable to discharge and/or uptake areas of ballast water.

IMO Secretary-General Mr. Efthimios E. Mitropoulos highlighted the urgent need to agree the proposed new mandatory instrument to regulate the management of ship ballast water and sediment and prevent the transfer of unwanted species from one ecosystem to another.

"This is an extremely serious environmental issue which IMO has been working on for more than a decade. The fact of the matter is that ships, by carrying thousands of tonnes of ballast water from one part of the world to another, can transfer pathogens and other micro-organisms and invasive species which have the capacity to distort and destroy the very delicate balance which exists in the ecosystem of the region where the ballast water is offloaded," Mr. Mitropoulos said.

"Unlike oil spills and other marine pollution caused by shipping, exotic organisms and marine species cannot be cleaned up or absorbed into the oceans. Once introduced, they can be virtually impossible to eliminate and in the meantime may cause havoc" he added.

Specific examples include the introduction of the European zebra mussel (Dreissena polymorpha) in the Great Lakes between Canada and the United States, resulting in expenses of billions of dollars for pollution control and cleaning of fouled underwater structures and waterpipes; and the introduction of the American comb jelly (Mnemiopsis leidyi) to the Black and Azov Seas, causing the near extinction of anchovy and sprat fisheries.

The problem of invasive species is largely due to the expanded trade and traffic volume over the last few decades. The effects in many areas of the world have been devastating. Quantitative data show the rate of bio-invasions is continuing to increase at an alarming rate, in many cases exponentially, and new areas are being invaded all the time. Volumes of seaborne trade continue overall to increase and the problem may not yet have reached its peak.

It is estimated that about 10 billion tonnes of ballast water are transferred globally each year, potentially transferring from one location to another species of sealife that may prove ecologically harmful when released into a non-native environment.

The problem of harmful aquatic organisms in ballast water was first raised at IMO in 1988 and since then IMO's Marine Environment Protection Committee (MEPC), together with the Maritime Safety Committee (MSC) and technical sub-committees, have been dealing with the issue, focusing in the past decade first on guidelines and then on developing the new convention.

GloBallast Programme
In order to help developing countries understand the problem, monitor the situation and prepare for the convention, IMO is implementing the GEF/UNDP/IMO Global Ballast Water Management Programme (GloBallast: ) and has provided technical support and expertise.

The conference will be preceded by the GloBallast 5th Global Project Task Force (GPTF) Meeting scheduled to take place also at the IMO Headquarters from 3 to 6 February 2004.

Scientists first recognized the signs of an alien species introduction after a mass occurrence of the Asian phytoplankton algae Odontella (Biddulphia sinensis) in the North Sea in 1903.

But it was not until the 1970s that the scientific community began reviewing the problem in detail. In the late 1980s, Canada and Australia were among countries experiencing particular problems with unwanted species, and they brought their concerns to the attention of IMO's Marine Environment Protection Committee (MEPC).

In 1991 the MEPC adopted MEPC resolution 50(31) - Guidelines for Preventing the Introduction of Unwanted Organisms and Pathogens from Ships' Ballast Water and Sediment Discharges; while the United Nations Conference on Environment and Development (UNCED), held in Rio de Janeiro in 1992, recognized the issue as a major international concern.

In November 1993, the IMO Assembly adopted resolution A.774(18) - Guidelines for Preventing the Introduction of Unwanted Organisms and Pathogens from Ships' Ballast Water and Sediment Discharges, based on the Guidelines adopted in 1991. The resolution requested the MEPC and the MSC to keep the Guidelines under review with a view to developing internationally applicable, legally-binding provisions.

The 20th Assembly of IMO in November 1997 adopted resolution A.868(20) - Guidelines for the control and management of ships' ballast water to minimize the transfer of harmful aquatic organisms and pathogens.

The development of the draft mandatory instrument has been continuing since then.

The top most unwanted "alien invaders" include:

Native to
Introduced to
Vibrio cholerae (various strains)
Various strains with broad ranges South America, Gulf of Mexico and other areas Some cholera epidemics appear to be directly associated with ballast water
Cladoceran Water Flea
Cercopagis pengoi
Black and Caspian Seas Baltic Sea Reproduces to form very large populations that dominate the zooplankton community and clog fishing nets and trawls, with associated economic impacts
Mitten Crab
Eiocheir sinensis
Northern Asia Western Europe, Baltic Sea and West Coast North America Undergoes mass migrations for reproductive purposes. Burrows into river banks and dykes causing erosion and siltation. Preys on native fish and invertebrate species, causing local extinctions during population outbreaks. Interferes with fishing activities
Toxic Algae(Red/Brown/ Green Tides)
Various species
Various species with broad ranges Several species have been transferred to new areas in ships' ballast water May form Harmful Algae Blooms. Depending on the species, can cause massive kills of marine life through oxygen depletion, release of toxins and/or mucus. Can foul beaches and impact on tourism and recreation. Some species may contaminate filter-feeding shellfish and cause fisheries to be closed. Consumption of contaminated shellfish by humans may cause severe illness and death
Round Goby
Neogobius melanostomus

Black, Asov and Caspian Seas

Baltic Sea and North America Highly adaptable and invasive. Increases in
numbers and spreads quickly. Competes for food and habitat with native fishes including commercially important species, and preys on their eggs and young. Spawns multiple
times per season and survives in poor water quality
North American Comb Jelly
Mnemiopsis leidyi
Eastern Seaboard of the Americas Black, Azov and Caspian Seas Reproduces rapidly (self fertilising hermaphrodite) under favourable conditions. Feeds excessively on zooplankton. Depletes zooplankton stocks; altering food web and ecosystem function. Contributed significantly to collapse of Black and Asov Sea fisheries in 1990s, with massive economic and social impact. Now threatens similar impact in Caspian Sea.
North Pacific Seastar
Asterias amurensis

Northern Pacific Southern Australia Reproduces in large numbers, reaching 'plague' proportions rapidly in invaded environments. Feeds on shellfish,
including commercially valuable scallop,
oyster and clam species
Zebra Mussel
Dreissena polymorpha
Eastern Europe (Black Sea) Introduced to:
Western and northern Europe, including Ireland and Baltic Sea;eastern half of North America
Fouls all available hard surfaces in mass numbers. Displaces native aquatic life. Alters habitat, ecosystem and food web. Causes severe fouling problems on infrastructure and vessels. Blocks water intake pipes, sluices and irrigation ditches. Economic costs to USA alone of around
US$750 million to $1 billion between 1989 and 2000
Asian Kelp
Undaria pinnatifida
Northern Asia Southern Australia,
New Zealand, West Coast of the United States, Europe and Argentina
Grows and spreads rapidly, both vegetatively and through dispersal of spores. Displaces native algae and marine life. Alters habitat, ecosystem and food web. May affect commercial shellfish stocks through space competition and alteration of habitat
European Green Crab
Carcinus maenus
European Atlantic Coast Southern Australia, South Africa, the United States and Japan Highly adaptable and invasive. Resistant to predation due to hard shell. Competes with and displaces native crabs and becomes a dominant species in invaded areas. Consumes and depletes wide range of prey species. Alters inter-tidal rocky shore ecosystem



IMO - the International Maritime Organization - is the United Nations specialized agency with responsibility for the safety and security of shipping and the prevention of marine pollution by ships.

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For further information please contact:
Lee Adamson, Senior External Relations Officer on 020 7587 3153 ( or
Natasha Brown, External Relations Officer on 020 7587 3274 (