Algal Bloom Observed at the Confluence of Flagler’s Dead Lake and Bull Creek

St. Johns River Water Management District scientists conducting routine monthly water sampling in the Lower St. Johns River Basin observed last week an algal bloom at the confluence of Dead Lake and Bull Creek in Flagler County. Samples were collected by the district and sent to the Florida Department of Environmental Protection for species identification.

An algal bloom is a rapid increase in the density of algae in an aquatic system. Algal blooms sometimes are natural phenomena, but their frequency, duration and intensity are increased by nutrient pollution. Algae can multiply quickly in waterways with an overabundance of nitrogen and phosphorus, particularly when the water is warm and the weather is calm. Reduction in nutrients can help to reduce the occurrence and intensity of harmful algal blooms. Algal blooms damage the environment, according to the Florida Fish and Wildlife Conservation Commission, because they replace vital food sources, clog fish gills, prevent sunlight from reaching seagrass and contribute to low oxygen “dead-zones” when they degrade. Some HAB species produce potent toxins that can persist in the water and enter the food chain. These toxins can be harmful to humans and animals.

District scientists routinely collect water and algae samples, particularly during periods when conditions are right for algal blooms. When an algal bloom is observed, samples are collected and additional tests are conducted to determine the algal species and whether algal toxins are present.

The District, DEP, local governments and utilities strive to reduce nutrient pollution entering water bodies. Since 2009, the District, DEP, the Florida Department of Health (which is responsible for sharing information with county health units) and the Florida Fish and Wildlife Conservation Commission have operated under a coordinated plan to respond to potentially harmful algal blooms.

For information about human health issues associated with algal blooms, contact your local health department. To report a fish kill or for information about potential impacts to wildlife, contact the Florida Fish and Wildlife Conservation Commission. For results of the lab analysis, subscribe to DEP’s algal bloom email updates here.