Monday, September 10, 2018

Florida: Red Tide Persists in Southwest

A bloom of the Florida red tide organism, Karenia brevis, persists in Southwest Florida and extends from Pinellas to northern Collier counties along ~120 miles of coastline. Observations of >1,000,000 K. brevis cells per liter (“high” concentrations) occurred in samples collected in or offshore of Sarasota, Charlotte, and Lee counties only. Relative to last week, multiple locations in Sarasota and Collier counties showed decreased cell concentrations. An aerial survey conducted on 9/6 as well as recent water sampling and chlorophyll satellite imagery indicate that the bloom of K. brevis likely extends offshore (10 miles or more) in some areas of the bloom region. Patchy accumulations of the marine cyanobacterium Trichodesmium were also observed ~10 miles offshore of Manatee and Sarasota counties. Persistent surface currents—prior to, during, and after the passage of Tropical Storm Gordon—likely played a role in transporting cells of K. brevis to the northwest. More specific details are provided below and at http://myfwc.com/redtidestatus.

In Southwest Florida over the past week, K. brevis was observed at background to medium concentrations in or offshore of Pinellas County, background to medium concentrations in Manatee County, background to high concentrations in Sarasota County, very low to high concentrations in or offshore of Charlotte County, background to high concentrations in or offshore of Lee County, and medium concentrations in Collier County.

In Northwest Florida over the past week, K. brevis was observed at very low concentrations in one sample collected from Bay County.

Additional samples collected throughout Florida over the past week did not contain K. brevis.

We continue to receive reports of fish kills in Southwest Florida. Over the past week, reports were received for multiple locations in Pinellas, Manatee, Sarasota, and Lee counties. More detailed information is available athttp://myfwc.com/fishkill.

Respiratory irritation was reported over the past week in Manatee, Sarasota, and Lee counties.

Forecasts by the USF-FWC Collaboration for Prediction of Red Tides for Pinellas to northern Monroe counties predict net northwestern movement of surface waters for most areas and net southeastern transport of subsurface waters over the next three days. A change from northwestern to southeastern surface transport is predicted to occur towards the end of this period.

This information, including maps and reports with additional details, is also available on the FWRI Red Tide website. The website also provides links to additional information related to the topic of Florida red tide including satellite imagery, experimental red tide forecasts, shellfish harvesting areas, the FWC Fish Kill Hotline, the Florida Poison Information Center (to report human health effects related to exposure to red tide), and other wildlife related hotlines.

To learn more about various organisms that have been known to cause algal blooms in Florida waters, see the FWRI Red Tide Flickr page. Archived status maps can also be found on Flickr.

The FWRI HAB group in conjunction with Mote Marine Laboratory now have a Facebook page. Please like our page and learn interesting facts concerning red tide and other harmful algal blooms in Florida.

Additional information regarding the current status of algal blooms in South Florida is being consolidated and posted on the Florida Department of Environmental Protection’s website: https://floridadep.gov/dear/algal-bloom.