Samples of discolored water and "froth" reported in February 2011 along Okaloosa and Walton county coastlines revealed a bloom of the nontoxic dinoflagellate but no adverse effects.
In late February 2011, the FWC's Fish and Wildlife Research Institute received a report from the National Oceanic and Atmospheric Administration regarding orange discolored water and "froth" offshore from Fort Walton Beach east to Topsail (see Figure 1).
Figure 1. Map of the 2011 Noctiluca scintillans bloom. Orange dots indicate water sample collection sites; orange oval represents aerial survey of the bloom
The Florida Department of Environmental Protection's Northwest District arranged with the Okaloosa County Tourist Development Council to collect water samples at James Lee Park. Volunteers from the FWC's Red Tide Offshore Monitoring Program also located discolored waters two miles off Destin Harbor in Okaloosa County (see Figure 2).
Figure 2. Noctiluca scintillans bloom offshore of Walton County on February 19, 2011
The volunteers described orange tidelines heading offshore with frothy aggregations alongshore. Water samples from both areas were analyzed and found to contain a bloom of Noctiluca scintillans.
Noctiluca scintillans is a large, bloom-forming dinoflagellate found in coastal regions worldwide. N. scintillans cells have a distinctive balloonlike appearance (see Figure 3). A pocket of air inside the cell wall allows this algal species to float and move within the water column of the ocean. The underside of the cell has a groove that houses a flagellum (whiplike appendage), a tooth, and a tentacle. The tooth is a specialized extension of the cell wall, and the prominent tentacle extends to the rear. N. scintillans is omnivorous, gulping organisms and small grains of sand. The photosynthetic organisms it feeds on can cause it to appear orange, red, pink, or green.
Figure 3. Noctiluca scintillans light micrograph
Noctiluca scintillans is nontoxic; however, blooms have been linked to massive fish and marine invertebrate kills from the toxic levels of ammonia that accumulate in surrounding waters. No fish kills or other adverse effects were reported in February or March as a result of the bloom in northwest Florida.
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