The success of many marine mollusk species is strongly dependent upon hydrodynamic conditions that retain or transport larvae to favorable settling grounds.To effectively manage these fisheries, it is therefore essential to understand the dominant circulation and mixing processes in these regions.In Shark Bay, a large inverse estuary in the arid northwest of Australia (Figure 1) the saucer scallop (Amusium balloti) trawl fishery has experienced dramatic inter-annual variability in catch, with actual catch levels often much lower than predicted (Figure 2).One possible explanation for this is that changing environmental conditions such as currents or temperature drive variability in recruitment from year-to-year.At present however, a lack of knowledge of the hydrodynamic processes limits our ability to understand the recruitment dynamics of this region.