The Vasse Wonnerup wetlands in south-western Australia are a Ramsar-listed, shallow barrier wetland that has been highly modified with the construction of floodgates to reduce seawater input. Within the community, it is perceived that reoccurring algal blooms and fish kill events are caused by eutrophication and opening the floodgates will dilute the water body, thereby reducing their occurrence. While nutrients fuel algal blooms, research has shown that other factors such as light penetration and stratification may be the key drivers that trigger a particular bloom. This study will determine what combinations of physiochemical variables are most likely to promote algal blooms or fish kill events. This will be done by measuring a suite of physiochemical profiles of the water column during summer, before and after the floodgates have been opened and relating it to chlorophyll a measurements, phytoplankton community species composition and fish kill events. This will inform the development of different scenarios of combinations of physiochemical variables, which will be tested in a structural equation model. These scenarios can be used to inform managers of the conditions that promote algal blooms and when it is appropriate to open the floodgates.