Effect of Beach Management Policies on Recreational Water Quality

摘要

When beach water monitoring programs identify poor water quality, the causes are frequently unknown. We hypothesize that management policies play an important role in the frequency of fecal indicator bacteria (FIB) spikes (enterococci and fecal coliform) at recreational beach sites. To test this hypothesis we implemented an innovative approach utilizing large amounts of data (n > 150,000 per FIB) to determine associations between the frequency of contaminant spikes and beach management. The large FIB database was augmented with results from a survey designed to document management policies for 316 beaches throughout the state of Florida. The association between FIB and survey data was analyzed using t-tests, ANOVA, factor analysis, and linear regression. Results show that beach geomorphology (beach type) was highly associated with exceedance of regulatory standards. Low enterococci exceedances were associated with open coast beaches (n=211) that have sparse human densities, no homeless populations, low densities of dogs and birds, bird management policies, low densities of seaweed, beach renourishment, charge access fees, employ lifeguards, without nearby marinas, and those that manage storm water. Factor analysis and a linear regression confirmed beach type as the predominant factor with secondary influences from grooming activities (including seaweed densities and beach renourishment) and beach access (including charging fees, employing lifeguards, and without nearby marinas). Our results were observable primarily because of the very large FIB databases available for analyses. Given the availability of these databases, a similar approach can be used to assess the associations between beach management policies and FIB levels within other parts of the U.S. and abroad.