Researchers have been looking into the possibility of using biocontrol methods to deal with the North Pacific sea star, which threatens the shellfish industry as it eats mussels. The species, native to Japanese and Alaskan waters, has been found in Tasmanian waters since 1986 and is believed to have arrived as larvae in ballast water.
Physical removal of the starfish may be the only viable solution, but it may be possible to introduce a disease agent for biocontrol. This could be the Japanese ciliate (a single-celled organism) Orchitophyra sp., which disables the host's reproduction. But further research is needed on possible effects on other native echinodermata (sea stars, sea urchins, sea cucumbers).
In 1997, Australia's Quarantine Inspection Service (AQIS) estimated that more than 170 species had been introduced to Australian waters, mostly through ballast water. Each year around 150 million tonnes of ships' ballast water are discharged into Australia's 64 international ports by 10,000 vessels from 300 overseas ports. In addition, some 34 million tonnes of ballast water is moved by domestic shipping each year from one Australian port to another. The Australian Ballast Water Program includes the Australian Ballast Water Management Advisory Council (ABWMAC) and its Research Advisory Group (RAG), administered by AQIS in Canberra.
Further Reading: AQIS Ballast Water Program: Web site: http://www.aqis.gov.au/ballastwater
E-Mail: ballast.water@dpie.gov.au
Address: Ballast Water Program; AQIS; GPO Box 858; Canberra ACT 2601 FAX: 61 2 6272 3036
Invasion of the Great Lakes
The invasion of the Great Lakes by alien species in ballast water probably dates back to the opening of the St Lawrence Seaway in 1959, when ocean-going ships began entering the Lakes in large numbers. By 1996, more than 130 alien species had been identified.
One trans-Atlantic invader is the European zebra mussel (Dreissena polymorpha), believed to have been introduced to the Great Lakes in the 1980s. Native to the Capsian and Black Seas, it spread throughout Europe in the 19th century.
In 1990, the United States federal government pledged US$11 per year to fight the zebra mussels, which were causing problems by swarming round 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.
