Keith Hayes, CSIRO Mathematics, Informatics and Statistics

Ecological indicators reduce the complexity of real-world systems to a small set of key characteristics that are useful for management and communication purposes. 

Reducing the complicated dynamics of natural ecosystems to a small number of indicators, however, represents a significant scientific challenge.  This challenge can be approached empirically or theoretically, but empirical approaches cannot currently be used in many of Australia’s marine regions due to, inter alia, a lack of a nationally consistent data set.

Modern theoretical approaches are usually couched within a conceptual framework known as the Driver-Pressure-State-Impact Response (DPSIR) framework. The DPSIR framework implies that the state of ecosystem variables will co-vary with anthropogenic drivers and pressures in predictable ways, but it does not describe how ecosystem variables will respond to drivers or pressures in any given situation - i.e. it does not identify indicators. Many theoretical methods for identifying indicators, such as unstructured lists, objective-indicators matrices, cartoons and influence diagrams cannot realistically predict the behaviour of ecological indicators in complex ecosystems subject to multiple simultaneous pressures. Qualitative and quantitative models provide the most realistic solution to this problem.

CSIRO and the Department of the Environment, Water, Heritage and the Arts (DEWHA) are currently working on a national approach to identify indicators based on the following components (see “Finding the ASX200 for marine ecosystems” earlier in this newsletter):

a) a set of key ecological features or values, that we wish to preserve, together with an analysis of the drivers and pressures that threaten these values; 

b) mapping of values and pressures to identify trends and patterns of co-occurrence (this is where the Marine Biodiversity Hub’s new data sets are proving valuable); 

c) qualitative modelling to identify potential ecological indicators amongst the ecological features that are exposed to threatening processes; and, 

d) indicator selection criteria to identify suitable indicators from a list of potential indicators.

This is a two-year project which follows on from the successful completion of a pilot project in the South-West Marine Region.

Contact:  keith.hayes@csiro.au