Summary

Caulerpa taxifolia was first discovered in NSW estuaries in 2000 and has now been found in 10 lakes or estuaries throughout the state. Considerable resources have been devoted to controlling the spread of the seaweed to new estuaries. The primary approach has been to focus on estuaries already infested and to limit the dispersal of Caulerpa from these places. To help do this, it would be useful to predict where new outbreaks might occur so that search efforts can be targeted. Further, to help inform control efforts and gain a better understanding of the magnitude of potential problems caused by Caulerpa, there is a need to predict the spread of the seaweed over time within an estuary.

This project was an initial attempt to model the spread of Caulerpa in Lake Conjola, where the extent of the seaweed has been mapped regularly by divers over the last few years. We tested how well a very simple model (based primarily on mathematical formulae, but little biological information) could describe changes in the coverage of Caulerpa over time. The results were encouraging in that the preliminary model could describe known changes in the coverage of Caulerpa quite well. The next step is to refine the model by incorporating other biological data and environmental information, and to extend the model to other lakes and estuaries in NSW.