Near-Shore Bacteria Monitoring for Health Protection: Case Study of Data from Selected Florida Beaches

Fecal indicator organisms (FIOs) have been monitored in public near-shore Florida waters by Florida Department of Health (FDOH). This research used publicly-available FDOH data to characterize the incidences when FIOs exceeded federal health guidelines for 17 beaches, in nine counties distributed along Florida’s coast, collected weekly over about nine years (January 2004–October 2012). The research selected, in each county, two beaches with the greatest number of exceedances—not representative of the Florida coastline, but those where the presence of FIOs appears to have been most frequent. The objective was to determine whether, in Florida’s most-impacted waters, sampling strategies can be judged sufficient to reliably detect exceedances in time to warn beachgoers of potentially unhealthful conditions. Results showed great variation among beaches: 5 of 17 analyzed beaches showed exceedances in fewer than 8% of all weeks sampled; 3 others showed exceedances in more than 30% of weeks sampled. Most (9) were in the 10–20% range. For a few beaches, data allowed assessment of duration of high-FIO episodes, suggesting most (>60%) persist for two days or less. Conclusions suggest that, during this 9-year period, sampling may have failed to detect a substantial number of incidences when FIO concentration exceeded health-based guidelines.