Estuary Chlorophyll Response-based Classification

One of the most widely used classification schemes for estuaries in NSW is that of Roy et al (2001) which is based on geology and geomorphology. Other schemes have used one or more of geomorphology, salinity and hydrology. A classification scheme has been developed that groups estuaries by their phytoplankton response to nutrient loading, specifically Total Nitrogen. The two factors used are the initial dilution of the load and the rate of subsequent flushing by tidal exchange through the estuary mouth. Three major classes, labelled by the dominant geomorphic type - lake, river and lagoon - were found to best explain the variation in phytoplankton populations expressed as chlorophyll a concentrations.; ; The classification scheme was used to stratify estuaries in NSW for the development of reference conditions and the design of a sampling program of chlorophyll a, turbidity and associated water quality parameters to assess estuary health.