The quantitative model that is being developed for the estuarine ecosystem of the Peel-Harvey Estuary will be used to explore how environmental change due to both anthropogenic and non-anthropogenic factors is likely to affect the ecosystem and to assess the potential for management action to ameliorate adverse impacts. The study is part of a broader ecosystem modelling study, initiated by WAMSI, that includes the development of qualitative models of the ecosystems of the Swan River Estuary, the Peel-Harvey Estuary and the Leschenault Estuary.
Statement: The estuarine ecosystem is represented by an Ecopath model, i.e. a mass-balance model, which describes the trophic interactions among the different functional groups into which the biota of the estuarine ecosystem have been classified. The dynamics of the resulting model may be explored using Ecosim, while Ecospace may be used to explore aspects of the system's behaviour that relate to the spatial distribution of the functional groups within the Estuary, which are determined by the distribution of different habitat types within the system. The estimates of biomass, production, and consumption and the composition of the diets of the various functional groups have been determined by undertaking an extensive review of the scientific literature and reports of studies relating to the estuary and its catchment, and by conducting workshops with stakeholders, managers, community representatives and scientists. The information obtained from this data gathering exercise is collated and synthesised to produce the data that are input to Ecopath. Where data from the Peel-Harvey Estuary are not available, data from the same or similar functional groups in other ecosystems are used to provide the values that are input to the model. After balancing and tuning, and extension to describe the distribution of the functional groups with respect to habitat, the resulting Ecosim and Ecospace models provide tools to explore the consequences of changes to the ecosystem.
Hector Lozano: Commonwealth Scientific and Industrial Research Organisation (CSIRO)