Algae bloom confirmed in Old Tampa Bay

Pinellas County Environmental Management has confirmed a bloom of algae in Old Tampa Bay stretching from Safety Harbor to the south end of the Bayside Bridge this week following reports of discolored water and strong odor.

The bloom of the organism Pyrodinium bahamense became visible last week and was confirmed with testing. Fish kills have also been reported in the area. Residents may experience an odor due to the algae bloom and fish kill.

Pyrodinium bahamense blooms typically occur in the summer months in Old Tampa Bay. It is not the organism known as Florida red tide, although blooms can have a reddish-brown tint.

Algae blooms can kill fish by decreasing levels of dissolved oxygen in the water. During nighttime and cloudy weather, low sunlight causes algae to switch from producing oxygen to consuming the oxygen needed by fish. During severe events, fish can suffocate from low oxygen levels.

The growth of algae like this species is fueled by nutrients, including those in fertilizers, sediment, yard waste and animal waste. These nutrients are carried into Tampa Bay and other local water bodies through stormwater runoff. Warm water temperatures and sunny weather after heavy rainfall also contribute to the blooms.

Pinellas County residents can help by remembering the slogan “Only rain down the drain” and properly disposing of grass clippings and other yard waste, pet waste and chemicals. Residents should also continue to follow the summer fertilizer ban, which prohibits the application of nitrogen or phosphorous to lawn and landscape plants from June through September.

If residents observe fish kills, they should call the Florida Fish and Wildlife Conservation Commission’s Fish Kill Hotline at (800) 636-0511 or visit MyFWC.com/FishKill to report them.