An Ecological Response Model for Botany Bay

Click here to download the final report on Ecological Response Modelling (4 Meg!)

Models are used by scientists to represent the behaviours of complex systems. They summarise known information and processes and help with predictions or explanations of system response. Models can range in complexity from a conceptual level to numerical models that are solved through computer applications. In this project two linked models are used to understand and predict impacts on the health of rivers and bays that may occur as a result of changes that occur in the catchment.

The first model developed by the Department of Environment and Climate Change (DECC) was a numerical model of Botany Bay and its waterways that uses understanding of physical, processes to predict changes in water characteristics under changing environmental conditions and changing catchment landuses. The second model estimated the impacts of changing water characteristics on the biological processes that can lead to the development of algal blooms and loss of seagrasses.

Open estuaries and bays are at all times subject to forces arriving from the ocean and the land. Complex models make it possible for us to capture the complexity of the many physical, chemical and biological parameters that interact and change on a continuous basis in this environment. Our chosen models work at a three-dimensional scale (i.e across the length, width and depth of Botany Bay ) and the results are generated over time.

The models that DECC used for this work have been developed especially for the purpose of examining water movement and biological processes in Australian coastal waters. They are a physical model called ELCOM (Estuary, Lake and Coastal Ocean Model) that uses geographical, oceanographic and meteorological data to compute the hydrodynamics of the Botany Bay waterways. An ecological model called , CAEDYM (Computational Aquatic Ecosystem DYnamics Model ), which concurrently computes the ecological processes. The ecological processes include inputs of sediments, biological particles and chemicals, and the transport, growth and reaction of these materials within the waterways. The two models are coupled together so that information is passed between them freely.

An ecological description of Towra Point

Towra Point, located on the southern shoreline of Botany Bay , is a Ramsar listed wetland of international importance. The DECC has prepared an ecological character description (ECD) of Towa Point, in which the key ecological components, processes and services of the wetland were identified. An ECD aims to provide qualitative benchmarks from which changes in ecosystem ecology can then be assessed. This report is being published by DECC and when it is available electronically it will be posted on this site.

Who we are

Alicia Loveless (Environmental Scientist - Modelling)
Kirsty Bennan (Environmental Scientist - Towra Point ECD)
Tyler Creese (Environmental Technician)
Geoff Coade (Project Manager)
Dr. Peter Scanes (Unit Leader)