The Centre For Water Research

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Ingrid Andrea Hillmer

Research Topic

Scales of interactions between physical processes, primary producers and nutrients in aquatic ecosystems

Project Description

Estimating internal biogeochemical fluxes is essential to the understanding of the dynamic of aquatic ecosystems. Different ecological approaches have been used to gain insight into internal cycling, but success has been limited. A critical point is the identification of the characteristic scales of patterns and the underlying processes affecting the behaviour of biological and chemical species. Failing to capture these scales leads to misinterpretations of field and numerical data. In this study, key aspects in the design of ecological surveys were identified to ensure that the internal biogeochemical processes were well represented. In the first part of this study, we defined an approach for the determination of a critical domain size that allows differentiation of the role of local and internal cycling from advective fluxes across the open boundaries in a shallow coastal ecosystem. In the second part, a new Lagrangian experimental design is proposed to quantify biogeochemical rates in situ by removing the effect of transport and mixing. The third part of the study focused on investigating the role of phytoplankton patchiness in modelled productivity, using a 1D and a 3D approach.

Publications

de Vilhena, L. C., Hillmer, I., and Imberger, J., 2010, The role of climate change in the occurrence of algal blooms; Lake Burragorang, Australia, Limnology and Oceanography, 55(3): 1188-1200

Harris, J., Hillmer, I. and Yeates, P., 2009, Lake Burragorang Algal Modelling SCARMS Update, Sydney Catchment Authority

Hillmer, I.A., 2008, The role of spatial variability in the understanding of ecosystem dynamics, 47th Australian Society of Limnology Congress, 29 September-3 October 2008, Mandurah, WA