Ballast water exchange in deep sea - as far aspossible from shore.

Non-release of ballast water.

Taking on only “clean” ballast water.

Treating the ballast water en route, such as with heating, chlorine or ultraviolet radiation.

Depositing the ballast water in special reception tanks at the port.

Great LakesInvasion of alien species to the Great Lakes dates back to the opening of St Lawrence Seaway (1959). By 1996, more than 130 alien species had been identified, including the European zebra mussel and the goby fish.

In Japan it is extensively cultivated as a fresh and dried food plant but in Australian coastal waters it is competing with native seaweeds and may significantly alter the feeding habitat of many indigenous Australian marine fish and shellfish species.

Now well established in most southern ports of Australia, its main threat is to southern scallop fisheries and other aquaculture industries.

Efforts to control the spread of this enormously fertile seastar have been unsuccessful and there is evidence of plague proportions threatening the shellfish industry.

Round gobies are aggressive fish and voracious feeders, which will vigorously defend spawning sites, thereby restricting access of other less aggressive species to prime spawning sites.

Because the ruffe grows very fast, has a high reproductive capacity and adapts to a wide variety of environments, it is considered a serious threat to commercial and sport fishing.

Alien invaders - putting a stop to the ballast water hitch-hikersAlien life forms that hitch a ride across the oceans in the ballast water of ships have been creating significant problems for the marine environment, public property and human health. Unlike oil spills and other marine pollution caused by shipping, exotic organism 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.

The International Maritime Organization is working through its Member States to tackle the ballast water problem. Guidelines for the Control and Management of Ships’ Ballast Water to Minimize the Transfer of Harmful Aquatic Organisms and Pathogens were adopted in 1997 (replacing earlier guidelines on the subject initially adopted in 1991) and IMO is now working towards adopting mandatory regulations on the management of ballast water.

It replaces native sea grasses and limits the natural habitat for larval fish and invertebrates. In 1984 it was first recorded covering an area of just one square metre off Monaco, today it covers thousands of hectares along the coasts of France, Spain, Italy and Croatia.

The comb jelly (an organism with similarities to a jellyfish) is a voracious predator on zooplankton, fish eggs and larvae - thereby depriving other species of this source of food. It has been largely responsible for the collapse of the sprat and anchovy fishing industries in the Black Sea.

A particularly hardy predator of marine invertebrates it has the potential to pose a serious threat to aquaculture and marine industries. In northern California, Carcinus maenas has already displaced common red rock crab species Cancer productus and Cancer magister.

AustraliaMore than 170 species have been introduced,

threatening the shellfish industry and altering the feeding habitat for native fish.

Ballast water, probably scooped up and pumped to the ballast tanks in or near the port where the cargo has been delivered, may contain all life stages of aquatic organisms.

Shipping is a crucial element in world trade, transporting more than 90 percent of goods and commodities around the world. Ballasting of ships is a necessary requirement for their safe operation when sailing empty to pick up a cargo, or with a light load, and it has been recognised that currently the only effective way to stop the spread of unwanted organisms is to prevent them being dumped in foreign ports.

Global transfer of ballast water: 10 billion tonnes /year (est.)

Ballast water per ship: Several hundred litres to morethan 100,000 tons, dependingon the size and purpose of thevessel.

Number of species of animalsand plants transported inballast water: 3,000/ day (est.)

In 1990, the United States federal government pledged 11 million US dollars per year to fight the zebra mussels, which were causing problems by swarming near water intake pipes of power plants and factories, in some cases clogging them completely. The zebra mussel also competes with native fish for plankton, affecting native fish populations.

EUROPEAN ZEBRA MUSSEL

ROUND GOBY

RUFFE

EUROPEAN SHORE CRABNORTHERN PACIFIC KELP

AMERICAN CTENOPHORE(Comb jelly)

TROPICAL GREEN ALGAE

GIANT FAN WORM

NORTHERN PACIFICSEASTAR

(Dreissena polymorpha)

Origins: EurasiaIntroduced to: Great LakesFirst sighting: 1980s

(Neogobius melanostomus)

Origins: Caspian and Black SeasIntroduced to: Great LakesFirst sighting: Lake Superior, 1995

(Carcinus maenas)

Origins: EuropeIntroduced to: San Francisco Bay area,

First sighting: West Coast United States: Early 1990s, southern Australia

Australia 1900 (Gymnocephalus cernuus)

Origins: EurasiaIntroduced to: Great LakesFirst sighting: 1980s

Some types of ships require large amounts of ballast water, primarily for journeys when the ship is unladen, including dry bulk carriers, ore carriers, tankers and liquefied gas carriers. Other ships require smaller quantities of ballast in almost all loading conditions, to control stability, trim and heel. They include container ships. ferries, general cargo ships, passenger ships, roll-on, roll-off ferries, fishing ships, fish factory ships and military ships.

(Undaria pinnatifida)

Origins: Northern PacificIntroduced to: Tasmania and

First sighting: 1987Port Philip Bay, Australia

(Sabella spallanzanii)

Origins: MediterraneanIntroduced to: Southern ports of AustraliaFirst sighting: 1980s

(Asterias amurensis)

Origins:

Introduced to:

First sighting: 1986

(Mnemiopsis leidyi)

Origins: East coast of the AmericasIntroduced to: The Black SeaFirst sighting: 1970s

(Caulerpa taxifolia)

Origins:

Introduced to: The MediterraneanFirst sighting: 1980s

Tropical seas, but maybe an exceptional strainused for ornamentalpurposes in aquaria.

IMOIMOIMO

Ballast water facts:

Possible solutions to minimize the risk oftransferring harmful aquatic organisms withballast water:

Japanese andAlaskan waters

Tasmania,Australia

GRAPHIC: Liz Gould; PHOTO CREDITS: Round Goby by David Jude and Ruffe by Gary Cholvek, both courtesy ofUniversity of Minnesota Sea Grant Program; Northern Pacific Seastar and Giant Fan Worm courtesy of CSIRO Marine Research, Australia.