Ships' ballast water was sampled on 28 occasions in four ports between November, 1976, and October, 1978.

A 100.,u plankton net was hand hauled vertically 5 times in each tank. Eight non indigenous species were obtained: 6 copepods, 
1 mysid and 1 amphipod. A further 14 species of copepod and 4 non­copepod taxa were found which have an Indopacific distribution. Twenty one copepods and twenty noncoepods could not be identified to species level which meant their zoogeographic affinities were undeterminable. The role of factors such as amount of water imported, _hull position, port of loading, voyage duration, mid ocean exchange, pumping survival and salinity and temperature shock was briefly examined.

Sediments in the bottom of ballast water tanks were examined on 9 occasions. Eight non indigenous species, 8 cosmopolitan species and twenty seven other taxa were found indicating a new potential vector for the dissemination of aquatic biota.

No evidence was obtained to indicate successful colonisation had taken place via either ballast water or ballast mud. However, because the identification and distribution of indigenous fauna are so poorly known it is equally impossible to conclude that successful colonisation has not taken place. The need to protect local species from predators, competitors and parasites requires that a sterilization policy be adopted. Preliminary estimates of the amount of sodium hypochlorite (liquid) and calcium hypochlorite (solid) required to kill animals in ballast tanks were made.