Introduced Marine Species

Marine pest incursions have been recognized as a major concern in Australia in recent years. With its proximity to Asia, Darwin Harbour may be particularly at risk. Of particular concern are those species that are transported though ballast water and on fouled hulls. These organisms are a major threat to a wide range of industries (including mariculture) and the environment. These organisms have several characteristics that allow them to outcompete native flora and fauna, such as a short reproduction period; large number of offspring per adult; rapid growth; and a wide tolerance to salinity, oxygen and pollution levels.

Although new incursions are unavoidable, the success of eradication is highly dependent on early detection. A prime example is the Black Striped Mussel incursion in 1999. By chance, a National Port Survey Program was conducting a baseline study for the Port of Darwin. During the Dry Season no pests were encountered, however, during Wet Season sampling, MAGNT and CRIMP staff encountered the Black Striped Mussel in Cullen Bay marina.

Further surveys found that other marinas also contained the pest. As the mussel was confined to a few marinas and was not encountered in open waters, the early detection was a key aspect in the successful eradication of the mussel from the marinas.

Besides the Black Striped Mussel, the CRIMP survey did not find any other listed marine pests. Follow up surveys by Fisheries (DBIRD) have encountered and eradicated small numbers of marine pests from Darwin Harbour. The marine pests of most concern are Taxafolia, a marine macroalgae that is currently a major pest in southern Australia, but has not yet Known from the NT; the Black Striped Mussel; and the Asian Green Lip Mussel.

Proceeding of the Darwin Harbour Public Presentation - February 2003
http://www.ipe.nt.gov.au/divisions/dhac/pres/pdf/pres_section2.pdf