Are blue-green algal blooms polluting your ponds?

Posted 2/11/21

Some stormwater ponds, have developed excessive amounts of blue-green algae, also known as cyanobacteria, blooming with toxins, and appearing as surface mats or scums.

You must be a member to read this story.

Join our family of readers for as little as $5 per month and support local, unbiased journalism.

Already have an account? Log in to continue. Otherwise, follow the link below to join.

Please log in to continue

Log in
I am anchor

Are blue-green algal blooms polluting your ponds?



For decades, stormwater ponds have served master-planned communities and commerce parks with environmental and aesthetic benefits. In some cases, these same stormwater ponds, have developed excessive amounts of blue-green algae, also known as cyanobacteria, blooming with toxins, and appearing as surface mats or scums. These ponds become unpleasant to see and potentially dangerous for wildlife.

It is a common problem in communities that is escalating.

Researchers and Extension agents at University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) have just released a guide, Best Management Practices for Blue-Green Algal (cyanobacterial) Blooms in your Stormwater Pond. The guide is a step-by-step fact sheet designed to empower residents with answers and resources for these man-made ponds that can become harmful if left unmanaged.

“This guide was created with the intent to raise awareness of the need for action and to determine what to do when these potentially harmful algae invade a stormwater pond,” said co-author Abbey Tyrna, a water resources agent with UF/IFAS Extension Sarasota County. “There are over 76,000 stormwater ponds throughout the state of Florida and right now there is no guidance on what to do, and no establishment of a threshold for when to act. We hope this manual fills that gap.”

“This fact sheet will help residents and property owners recognize discolorations in the water that can be indicative of algal blooms to prevent potential exposure, provide information on who they can contact to help identify the algae present and their toxins, while providing some common treatment methods for algal management,” said co-author Dail Laughinghouse, assistant professor of applied phycology at the UF/IFAS Ft. Lauderdale Research and Education Center.

Stormwater ponds are designed to serve as a filter and temporary reservoir to prevent pollution from seeping into our waterways while prevent flooding during the Sunshine State’s rainy season. When rainwater lands on parking lots, driveways, rooftops, and other hard surfaces, the rainfall that does not soak into the ground is known as stormwater runoff. This stormwater runoff flows into a man-made neighborhood stormwater pond through grates, pipes, shallow swales, or ditches.

Stormwater ponds, Florida’s most common method for stormwater management, are specifically designed to prevent flooding and protect downstream waters from pollutants. Stormwater ponds also serve as aesthetic bodies of water situated in the center of communities increasing the number of surrounding homes with water views and creating high value for visual enjoyment but not recommended for swimming.

The problem lies in that stormwater pond water quality is not regulated or managed by state or county agencies, despite vast implementation for most developments since the 1980s to meet stormwater management rules required under Chapter 62-25 of the Florida Administrative Code, said Tyrna. .

This fact sheet walks communities and property owners through the steps and the resources needed to properly identify and manage potentially harmful algae living and blooming in their backyard waters. By increasing awareness, we hope to protect Floridians and their pets from preventable harm.

The 4-page best practices guide is intended to assist Floridians living, recreating, and working around stormwater ponds with answering the following questions:

• How do you recognize the visual presence of potentially toxic algae?
• When should you place publication notification?
• When and how often should you sample the water?

• Where to send those samples at UF/IFAS?
• When is it safe to take down signage notifications?
• How to treat the algae if you choose to try to get rid of it?
• How to determine potential causes and consider pond enhancement projects.

Additional resources on the fact sheet provide direction and insight on why stormwater ponds are needed, how to manage them to keep them healthy, along with suggested plant directories that are beneficial for ponds, and more. The guide is available online from the UF/IFAS Extension Sarasota County Water Resources website at

UF/IFAS, algae, algal blooms, blue-green