Selection of parameters in the design of beach coastal water quality monitoring programs

Abstract

Water quality analyses form an important part of a beach monitoring program in order to ensure the water’s recreational adequacy, aesthetic value, and ecosystem health. While the inclusion of multiple water quality parameters in the program’s design allows for comprehensive analyses, limiting the number of parameters included may be beneficial to balance costs and permit sufficient spatio-temporal sampling. In order to inform decision-making with regards to the selection of parameters, this study presents an analysis of the relationships between 16 water quality parameters, based on data collected from 61 beaches of the Caribbean and Pacific coasts of Colombia between 2001 and 2011. Correlation coefficients show moderate to very strong relationships among parameters related to water clarity (turbidity, transparency, total suspended solids) and among microbiological parameters, suggesting that the number of these parameters selected for monitoring could be reduced. In consideration of these results as well as other factors such as costs, technical complexity of analyses, and the identification of established reference values, it is recommended that a beach water quality monitoring program include as a minimum, the basic in situ arameters (temperature, salinity, pH and dissolved oxygen), one parameter related to water clarity (turbidity), and at least one microbiological parameter (Enterococos o Escherichia coli). Selection of the specific parameters to be included will depend largely on the technical capacity to measure each parameter, the reference values identified or comparison, available financial resources, as well as the specific priorities and local characteristics of each beach.