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Beach-goer behavior during a retrospectively detected algal bloom at a Great Lakes beach
Citation:
Hilborn, E, W. Krueger, B. Schaeffer, R. Stumpf, E. Sams, AND Tim Wade. Beach-goer behavior during a retrospectively detected algal bloom at a Great Lakes beach. 2016 Recreational Water Conference, New Orleans, LA, April 12 - 15, 2016.
Impact/Purpose:
Algal blooms are more commonly reported at recreational beaches in the US. The Office of Water is actively working to develop recreational water guidelines for algal bloom toxins to guide beach managers. This suggests that people do not necessarily avoid bloom exposure during recreational activities.
Description:
Algal blooms occur among nutrient rich, warm surface waters and may adversely impact recreational beaches. During July – September 2003, a prospective study of beachgoers was conducted on weekends at a public beach on a Great Lake in the United States. We measured each beachgoer’s activity at the start and end of their beach visit and the environmental factors: water and air temperature, wind speed and wave height at the study site each day. At the time, there was no notification of algal blooms; we retrospectively evaluated the presence of algal blooms using MERIS data from the Envisat-1 satellite. A total of 2840 people participated in the study over 16 study days. The majority (55%) were female, and 751 (26%) were < 18 years of age. An algal bloom was detected retrospectively by remotely sensed satellite imagery during August 16 – 24. This peak bloom period (PB) included 4 study days. During PB study days, more study participants 226/742 (31%) reported body contact with the water compared to contact 531/2098 (25%) on non-peak days. During the 4 PB days, of the environmental factors, only mean water temperature was significantly different, 250 C vs. 230 C (p<0.05) from other days.These results suggest that beachgoer body contact with water was not deterred by the presence of an algal bloom, and that interventions to actively discourage water contact during a bloom are needed to reduce exposure to blooms. This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.