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In late May 2010, the FWC's Fish Kill Hotline began receiving reports of dead and dying fish in the lower St. Johns River (St. Johns and Putnam counties). Water samples indicated high concentrations of a harmful cyanobacterium (blue-green alga) species, Aphanizomenon cf. flos-aquae. Aphanizomenon is found in fresh water bodies throughout Florida, and blooms of this species are common in the St. Johns River. Blooms can appear as blue-green threads in the water column or as surface scum during summer and fall months. Aphanizomenon produces several types of toxins that can affect the human nervous system and liver. High concentrations of cells can deplete dissolved oxygen in surrounding waters, resulting in fish kills.

In late May 2010, the FWC's Fish Kill Hotline began receiving reports of dead and dying fish in the lower St. Johns River (St. Johns and Putnam counties). Water samples indicated high concentrations of a harmful cyanobacterium (blue-green alga) species, Aphanizomenon cf. flos-aquae. Aphanizomenon is found in fresh water bodies throughout Florida, and blooms of this species are common in the St. Johns River. Blooms can appear as blue-green threads in the water column or as surface scum during summer and fall months. Aphanizomenon produces several types of toxins that can affect the human nervous system and liver. High concentrations of cells can deplete dissolved oxygen in surrounding waters, resulting in fish kills.

In May 2011, blooms of Ceratium hircus were identified in portions of the Caloosahatchee River along with blue-green algae blooms that began the previous month. Ceratium belongs to a group of algae known as dinoflagellates. This dinoflagellate is nontoxic but may cause oxygen depletion in the surrounding waters at high cell concentrations. No adverse effects from this bloom were reported. Ceratium can be found in cold and warm waters and from freshwater to saltwater environments worldwide. Some species are bioluminescent, meaning they light up the water with a blue glow at night.

Photo credit: Sanibel-Captiva Conservation Foundation

On May 10, 2010, during an aerial survey to assess the extent of the Deepwater Horizon oil spill in the Gulf of Mexico, staff with the FWC's Fish and Wildlife Research Institute noted discolored water that was not oil-based, but rather appeared to be an algal bloom. Examination of a water sample identified a bloom of Ceratium, a single-celled organism belonging to a group of algae called dinoflagellates. This dinoflagellate is nontoxic but may cause oxygen depletion in the surrounding waters at high cell concentrations. No adverse effects from this bloom were reported. Ceratium can be found in cold and warm waters and from freshwater to saltwater environments worldwide. Some species are bioluminescent, meaning they light up the water with a blue glow at night.

Related article
Deepwater Horizon Oil Spill Response

On May 10, 2010, during an aerial survey to assess the extent of the Deepwater Horizon oil spill in the Gulf of Mexico, staff with the FWC's Fish and Wildlife Research Institute noted discolored water that was not oil-based, but rather appeared to be an algal bloom. Examination of a water sample identified a bloom of Ceratium, a single-celled organism belonging to a group of algae called dinoflagellates. This dinoflagellate is nontoxic but may cause oxygen depletion in the surrounding waters at high cell concentrations. No adverse effects from this bloom were reported. Ceratium can be found in cold and warm waters and from freshwater to saltwater environments worldwide. Some species are bioluminescent, meaning they light up the water with a blue glow at night.

Related article
Deepwater Horizon Oil Spill Response