Australia’s Tropical Northern Seas encompass a region of rich oceanographic complexity and ecological diversity. IMOS observations extend from Ningaloo Reef in the west, the resource rich North West Shelf to Darwin and along Queensland’s Great Barrier Reef (GBR).
One of the primary objectives of the Australian Government NCRIS funded IMOS arrays is to monitor boundary currents comprising of the Leeuwin, Holloway, Gulf of Papua and the East Australian Currents and their associated eddies. In addition cross-shelf exhanges are also observed through processes such as internal waves and subsurface cold water intrusions.
Observations from satellite observations to in situ fixed and roving platforms reveal a rich amount of detail of the boundary currents which have a strong seasonal variation. Shelf waters exhibit a transition from well-mixed in winter to a strongly thermally stratified water column from spring-time warming through summer. Internal tides can then are able propagate into the shallower shelf water. Along the GBR there are periods of sustained cold and nutrient rich intrusions across the shelf through the reef matrix. In this paper a number of examples are provided across the tropical north showing how the environmental conditions can influence fish behaviour and feeding grounds.