Temporal variations analyses and predictive modeling of microbiological seawater quality

Area of Science:

• Environmental Science
• Public Health
• Microbiology

Background:

• Bathing water quality is crucial for public health and tourism.
• Current EU methods yield results after 2.2 days, providing outdated information.
• Beach assessment is affected by sampling, environmental factors, and differing water standards.

Purpose of the Study:

• Examine daily temporal variations in microbiological parameters.
• Investigate the influence of sampling time on beach management decisions.
• Evaluate different water quality criteria and identify reasons for exceeding standards.

Main Methods:

• Analyzed fecal indicators (E. coli, enterococci, C. perfringens) and non-fecal parameters (S. aureus, P. aeruginosa).
• Compared national (Croatian), EU, and U.S. EPA evaluation criteria.
• Developed a predictive statistical model incorporating environmental parameters.

Main Results:

• Highest fecal indicator concentrations were observed early in the morning (6 AM).
• Escherichia coli criteria are more sensitive to fecal pollution than enterococci.
• Croatian national criteria are stricter than EU and U.S. EPA standards.

Conclusions:

• Predictive models show significant potential for recreational water monitoring.
• Solar radiation and precipitation are key environmental factors influencing water quality.
• Further model development can enhance public health protection in bathing areas.