Echo sounder, sonar and radar operators and navigation course

Most Australian abalone fisheries are fully exploited and a comparison of the total catch of blacklip abalone, Haliotis ruber, in the three south-eastern states indicates a decline in population size from south to north. The catch distribution from New South Wales parallels that trend. This decline...

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...