How will the key science questions be addressed?

How does the large-scale circulation control the links between the physical, chemical and biology environment?

The main circulation patterns are obtained from the Argo network. Oxygen equipped floats provide inferences of biological connections. These data will inform temporal and spatial distributions of species obtained from CPR and bioacoustics.  Investigating the linkages between Oceanographic data (salinity, water temperature) and biological response: of apex predators facilitated by animal borne monitoring; for lower trophic levels, physical-chemical measurements collected concurrently with CPR; for mid trophic levels ipso facto.  The SOTS mooring will acquire a high resolution time series of integrated observations of physical, biological and chemical properties in the Sub-Antarctic Zone southwest of Tasmania.

What controls the temporal variation in biogeochemical fluxes of the ocean and how will they respond to climate variability?

This will be addressed initially using Ocean Colour observations.  The SOTS mooring provides the only Southern Ocean set of measurements to resolve the temporal variability of biogeochemical fluxes.  When time series of underway nutrients become available they will be integrated with complementary physical measurements to determine forcing mechanisms.  Existing datasets from individual coastal moorings, research cruises (not within IMOS) will be assimilated into biogeochemical models.

Are we able to determine the spatial and temporal variability of the main biological resources?

Variability in nutrient distribution will be assessed by nutrient mapping from SOOP vessels (when available), fluctuations in lower trophic levels (productivity) will be monitored using SRS and long-term CPR records, variability at mid-trophic levels will be measured using bio-acoustic data, alterations in foraging activity in response to variability at lower trophic levels by apex predators will be assessed by monitoring foraging behaviour at sea and long-term changes in demographics.  The SOTS mooring provides integrated high-res data from a single Southern Ocean location.

What is the relationship of rapid mixed-layer dynamics in the Southern Ocean on plankton production and carbon transports?

The suite of observations collected from the SOTS mooring is aimed to determine this relationship.

How do the different trophic levels respond to climate variability and climate change?

Variability in nutrient availability with changes in upwelling and current flows will be assessed by nutrient mapping from SOOP vessels, fluctuations in lower trophic levels (productivity) will be monitored using SRS and long-term CPR records, alterations at mid-trophic levels will be measured using bio-acoustic data, alterations in foraging activity by apex predators will be assessed by monitoring foraging behaviour at sea and long-term changes in demographics.

Can we determine a more complete understanding of trophic connectivity and how it might be altered under a changing climate?

Sustained observations of trophic level interactions through CPR, Bio-Acoustics and MAPSO will be used to integrate information from multiple trophic levels with available information on ecosystem structure and oceanography to identify Areas of Ecological Significance.

What are the affects of climate change on:

• The structure and functioning (energy, water and nutrient cycling) of ecosystems
• The processes and phases of life cycles

Observations from all of the trophic levels obtained from CPR, bioacoustics, MAPSO will be related to the background forcing provide by the physical properties (Argo, XBT, gliders, SRS).

Can we determine indices for assessing ecosystem health and for fisheries management?

To incorporate key physical and biological information into spatial models that can be used to inform management strategies for the region we will need to statistically examine the relationship between physical features (ARGO, SOOP, SOSS) and spatial and temporal patterns in biological communities (CPR, bio-acoustics, MAPSO).

How do the changes in boundary currents (EAC and LC) influence ecosystem productivity?

All of the current meter arrays, glider transects, XBT sections, Argo floats, satellite observations will be used with the information from the CPR, bioacoustics, coastal moorings to determine the interrelationships.

How do cross-shelf exchange processes (boundary currents and shelf regions) influence coastal productivity and ecosystem connectivity?

This aim is primarily the responsibility of the regional nodes and will involve the combination of high resolution glider data, coastal moorings, NRS, SRS data, coastal radar.

How do changes in ocean acidification influence key vulnerable ecosystems such as the Southern Ocean, coral reefs and the continental shelves?

Measurements of CO₂ fluxes from the underway systems on the research vessels (particularly the Auroa Australis and L' Astrolabe) and the coastal stations will provide inputs to understand the acidification influence in these regions. The SOTS mooring provides an integrated set of observations to resolve ecosystem responses that effect carbon cycling, and marine responses to ocean acidification in the Southern Ocean.