Enterococcus exceedances related to environmental variability at New Jersey ocean beaches

Area of Science:

• Environmental Science
• Public Health
• Microbiology

Background:

• Microbial pollution at beaches is a global concern, worsened by rainfall, especially near urban areas.
• Enterococcus bacteria are indicators of fecal contamination and potential health risks at recreational waters.
• Previous studies acknowledge rain as a predictor of Enterococcus, but a direct link at specific NJ beaches was unexamined.

Purpose of the Study:

• To investigate the relationship between rainfall and Enterococcus levels at five Monmouth County, NJ beaches.
• To determine if Enterococcus levels differ significantly between beaches and across seasons.
• To develop a predictive model for Enterococcus exceedances using environmental parameters.

Main Methods:

• Collected water samples for Enterococcus analysis and water quality parameters at five NJ beaches during dry and wet conditions.
• Employed statistical analyses to compare Enterococcus levels across sites and seasons.
• Utilized multiple linear regression and hindcast modeling with environmental data (rainfall, temperature, water level).

Main Results:

• Significant differences in median Enterococcus levels were observed among the studied beaches.
• Elevated Enterococcus levels were detected across a range of water temperatures (6.5–22.2°C).
• Rainfall, water temperature, and water level were identified as significant factors influencing Enterococcus concentrations.

Conclusions:

• Environmental factors, particularly rainfall, play a crucial role in Enterococcus contamination at NJ beaches.
• Predictive models based on environmental data can enhance current Enterococcus monitoring strategies.
• Optimized monitoring, potentially year-round or using predictive models, can improve the detection of exceedance events.