Modelling the effects of ‘coastal’ acidification on copper speciation

• Published in: Ecological Modelling
• Main Authors: Richards, Russell, Chaloupka, Milani, Sano, Marcello, Tomlinson, Rodger
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2011
• Subjects: Ocean acidification; Copper speciation; Stochastic model; Coastal waters; Moreton Bay; 2302 Ecological Modelling; Moreton
• Online Access: https://espace.library.uq.edu.au/view/UQ:706664

We present here a copper speciation model that accounts for the long-term ('coastal-acidification') and short-term (daily and seasonal variation) variability in water pH and water temperature. The developed model is applied to a sub-tropical estuary (Moreton Bay, Australia) at a one hundred year time scale so that outputs are consistent with climate change projections. The model predicts that the mean cupric ion concentration (Cu) in the estuary will increase by 115% over the next 100 years as a result of the projected decrease in pH and increase in water temperature. Through calibration, the estimated concentration of copper-complexing dissolved organic matter (DOM) in the estuary is found to be 22.5nM. An increase in the concentration of Cu, which is the most toxic and bioavailable form of copper, has implications for ecosystem health and may have a negative effect on the detoxifying capacity of DOM. Models that provide a framework for coupling biological, chemical and physical processes are important for providing a holistic perspective of coastal systems, especially for better understanding a system within the context of climatic and non-climatic drivers.