How will the key science questions be addressed?

Quantify the daily to decadal variation of planktonic communities in relation to oceanographic and climate-driven changes in physical and chemical ocean properties.

The current time series of plankton observations/samples in the East Australian Current (EAC) (1997 to 2009 archive) is too short to reliably detect a climate change signal from natural patterns of climate variability.  However, by examining the physical and biological responses to contemporary climate variations, we will determine responses that may be indicative of future climate change.  We will address temporal variability by making high-frequency measurements of phytoplankton using the ANMN, ANFOG and AUV facilities.  Additionally we will use the SOOP-CPR data from Brisbane-Sydney-Melbourne, and the corresponding bio-acoustic transect. To assess spatial dynamics, we will use a multi-faceted approach: synoptic views of ocean colour using the SRS facility, quasi-synoptic assessments of chl-a fluorescence and particle backscatter using ocean gliders, and the development of a regional ocean model so that single-point observations such as those at moorings can be placed into a spatial context.

Quantify rocky reef biota variables (kelp distribution and abundance) associated with climate variability, at deep reefs along the NSW to Tasmanian coast.

We will use the AUV facility to document changes in kelp among depths and among latitudes throughout the distribution of kelp in NSW.  On each dive, associated AUV-based measurements of temperature, light levels and samples for nitrate analysis will enable interpretation of the biological signal in the context of local environmental conditions.  Observations in NSW will form part of a set of sites on the east coast, where reefs will be monitored in SE Qld, NSW, Victoria and Tasmania using AUV technology.

Relationship of the EAC, its eddies and oceanographic conditions on fisheries, and movements by fish and sharks.

Observations are designed as a set of cross-shelf receivers to ensure that data on fish movement covers the necessary geographic extents and ranges of conditions and is overlaid by oceanographic monitoring.  The observations across a broad spectrum of conditions will give new insight into role of ocean dynamics on movements, habitat use and site fidelity for predatory fish in the coastal zone.  Simultaneous and sustained monitoring will indicate links between hydrography and fish migration, facilitated by observations from the ocean moorings, coastal radar, BLUElink, SOOP, and cross shelf data collected via proposed fine scale temperature recorders positioned on the bottom and surface of existing AATAMS line mooring arrays.  

Quantify the seasonal and yearly variation of upper-predator (fish and marine mammal) communities.

Passive acoustic observatories will capture vocalisations of great whales and nearby fish at scales of km’s (fish) to many tens of km’s (great whales).  The passive acoustic array was designed specifically to allow source tracking for sources which arrive coherently on all receivers.  This will not only record the presence of cetaceans and fish in the absence of visual detection but will also allow us to track animal movements, seasonal occurrence, distribution, and behaviour, including dive and migratory patterns, particularly for cetaceans.  These trends can then be related to larger scale physical features for elucidation of how the physical environment impacts on the respective animal population.