The relatively high catch of invertebrate species in Western Australia compared to finfish is in sharp contrast to other regions of the world where finfish production usually dominates. This low level of finfish production is primarily due to the Leeuwin Current which brings warm, low nutrient waters southward along the edge of the continental shelf of the Western Australian coast. By contrast, the other eastern boundary currents in the Southern Hemisphere (the Humboldt and Benguela Currents off the west coasts of South America and southern Africa respectively) are associated with upwelling of cool, nutrient-rich waters flowing northward, resulting in high rates of primary production and a correspondingly large finfish production.

There is an increasing awareness of the importance of oceanic processes such as advection, water temperature, etc. for recruitment to both pelagic and benthic fisheries. Previous studies off Western Australia have demonstrated that the Leeuwin Current and winds both play a key role in the settlement of rock lobster pueruli, with important consequences for the fishery 3 to 4 years later, and there are also indications of environmental influences on many other commercial fisheries.

his project has compiled the first comprehensive set of environmental data off Western Australia to enable these relationships to be further examined: satellite-derived sea-surface temperatures (SST), local in situ temperatures and salinities, coastal sea levels, the Southern Oscillation Index, and winds. In the absence of direct current measurements, monthly and annual coastal sea levels are used as an approximate "index" of the strength of the Leeuwin Current. SST gradients from both global-scale (the Reynolds dataset) and locally-received satellite data have also been derived as potential complementary indices of the thermal structure of Western Australian waters, but difficulties with adequate cloud-clearing have hampered work with the local data.