Red tide predictions for weekend: Low

The FWC is now offering daily updates of its red tide water samples.

Low concentrations of red tide are predicted in Island waters from Oct. 13-15 by NOAA and the University of South Florida/Florida Fish and Wildlife Conservation Commission Collaboration for Prediction of Red Tides.

Today’s report from the FWC shows that red tide had decreased in waters off Anna Maria Island before Hurricane Michael passed by on Oct. 10.

Wildlife affected by red tide


At least 172 manatees have died during the red tide bloom that has plagued Southwest Florida since October 2017, and which reached Anna Maria Island on Aug. 3.

To date, 67 dead manatees tested positive for red tide, and red tide is suspected in 105 manatee deaths, according to the FWC.

Nine manatee deaths have been recorded in Manatee County so far this year, three in Anna Maria Sound; none are confirmed from red tide.

So far this year, 676 manatees have died in state waters, compared to 538 in all of 2017.

Sea turtles

Since the red tide began locally in August, the Mote Marine Laboratory Stranding Investigations Program, serving Sarasota County and part of Manatee County, has taken in 216 sea turtles, only 14 of which were alive, with many of the deaths due to red tide exposure. Anna Maria Island Turtle Watch and Shorebird Monitoring has recorded 36 sea turtle strandings.


Mote has recorded 21 deceased bottlenose dolphins, 10 from red tide exposure. In all, 66 dolphins have stranded during the red tide as of Oct. 11, according to NOAA. No new strandings have been reported since Sept. 27.


Wildlife Education and Rehabilitation Inc. in Bradenton Beach has taken in between 60-70 birds sick from eating fish contaminated with red tide, mostly cormorants and laughing gulls.

The Oct. 12 report shows that Manatee County water samples with medium or high levels of red tide decreased from 5 percent to 25 percent from the previous week.

Low concentrations of red tide were found in water samples on Oct. 8 at Longboat Pass, with very low concentrations at the Rod & Reel Pier in Anna Maria and background concentrations at Cortez Beach in Bradenton Beach, with none at the Palma Sola Bay bridge.

Red tide foam
Foam washed up on Anna Maria Island’s beaches after Hurricane Michael passed Wednesday. Scientists warn that foam has high concentrations of red tide and should not be touched. – Cindy Lane | Sun

Background concentrations of red tide cause no anticipated effects. Low levels can cause respiratory irritation, shellfish harvesting closures and possible fish kills. Medium levels can cause respiratory irritation, shellfish harvesting closures and probable fish kills. High levels can cause all of the above, plus water discoloration.

Respiratory irritation was reported on Oct. 4, and from Oct. 6-8 and Oct. 10-11 at Coquina Beach (Bradenton Beach), and Oct. 5-7 and Oct. 10-11 at Manatee Beach (Holmes Beach).

Fish kills also were reported in Manatee County over the past week.

Red tide fish kill
Dead fish killed by red tide washed up on the beach.  Manatee County crews rake the beaches daily. – Cindy Lane | Sun

Red tide is a type of algae that emits a neurotoxin when it blooms. Deadly to fish, sea turtles, marine mammals and shorebirds that feed on affected fish, red tide makes shellfish unfit to eat, and can cause respiratory irritation in people, especially those with asthma, COPD or other respiratory diseases.

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