Officials have identified blooms of blue-green algae (also called cyanobacteria) in Hancock County, Mississippi. The confirmation of this algae triggered Mississippi beach closures beginning in June. At this point, officials closed all beaches along the Mississippi coast. While the blooms are 120 miles away from the Alabama coast, officials are monitoring waters for the harmful algal blooms (HAB).
P.J. Waters, an Alabama Extension specialist and interim director of the Auburn University Marine Extension and Research Center, said historic flooding and the opening of the Bonnet Carre spillway has resulted in unusually low salinities in the Mississippi Sound. Low salinity is a known contributor to environmental conditions surrounding blue-green algae.
Blue-green Algal Blooms
Alan Wilson, an associate professor in Auburn University’s School of Fisheries, Aquaculture and Aquatic Sciences said blue-green algae includes more than 1,000 microscopic species. While they can be found across the globe, including deserts and oceans, the majority of them are found in freshwater.
Some blue-green algal species can produce liver and/or neurological toxins that can be harmful to animals, including humans. Algal blooms occur when there are rapid increases in the amount of algae in the water. Specific environmental conditions must be present to produce a blue-green algal bloom and red tide.
Blue-green algae, like plants that photosynthesize, need resources to thrive. These include water, carbon dioxide, sunlight and nutrients. Blooms will occur as long as the conditions are right for the blooming species to thrive. Warm temperature and low salinity can promote faster growth.
Freshwater a Factor
Wilson said elevated salinity is likely one of the reasons conditions are not typically conducive for freshwater blue-green algae on the Gulf coast.
“Cyanobacterial blooms happen frequently in inland, freshwater systems,” Wilson said. “They are less common in coastal areas. On the coast, red tides tend to happen, but they are dinoflagellates, not cyanobacteria.”
Waters said an increase in freshwater in the Mississippi Sound has been a factor.
“In two of the last three years, freshwater has been an issue for shellfish in the Mississippi Sound,” Waters said. “Excessive rainfall in June 2016 was one of the main contributors of freshwater in the Sound.”
Contact with contaminated water can cause rashes. Swallowing water—even accidentally or in small amounts—can cause serious health conditions if toxins are present. Children, adults and pets should not be allowed near the water to prevent touching or swallowing.
Body parts exposed to contaminated water should be washed thoroughly with soap and water immediately.
Do not consume seafood harvested in waters closed to fishing. A wide range of symptoms can be experienced when one consumes contaminated seafood. Seafood sold at markets and in restaurants is safe to eat during a HAB event because seafood must be harvested from waters open to fishing in order to be sold. Symptoms depend on the amount and type of toxin(s) and may include:
• abdominal pain
Learn more about the health concerns associated with HABs from the Environmental Protection Agency.
The Alabama Department of Public Health’s (ADPH) Seafood Division is responsible for testing water quality as well as opening and closing waters to protect consumers with enforcement provided by the Alabama Department of Conservation and Natural Resources’ Marine Resources Division.
Waters said the ADPH Seafood Division conducts routine tests to monitor water quality, including the presence of harmful algal blooms. The Mississippi Department of Marine Resources does the same job in their state.
Check for beach closures by visiting the Alabama Department of Environmental Management online and the Alabama Department of Public Health (ADPH). Look for signage to indicate beach closures. There are 26 beach access sites, as well as additional water sites, monitored in Alabama.
Lori Wheeler is County Extension Coordinator.