Model assists in estuarine susceptibility classifcation

The susceptibility of estuaries to nutrient loading is an important issue that cuts across a range of management needs. Scavia and Liu (2009) used a theory-driven but data-tested simple model to assist classifying estuaries according to their susceptibility to nutrients. This simple nutrient-driven phytoplankton model is based on fundamental principles of mass balance and empirical response functions for a wide variety of estuaries in the United States. Analysis on the efficiency factor suggests that estuaries with the ratio of river inflow to estuarine volume (Q/V) greater than 2.0 per year are less susceptible to nutrient loads, those with Q/V between 0.3 and 2.0 per year are moderately susceptible.  This simple model analysis provides a first-order screening tool for estuarine susceptibility classification. The paper is available at http://sitemaker.umich.edu/scavia/files/scavia_and_liu_2009.pdf