Red tide bloom continues offshore at Manatee, Anna Maria Island. What we know

The harmful red tide algal bloom continues to linger at significant levels in waters around coastal Manatee County this week, but the beaches have been spared.

Karenia brevis, the organism that causes red tide, was detected at “medium” levels in waters up and down Anna Maria Island and Longboat Key on Monday, according to the Florida Fish and Wildlife Conservation Commission. At medium levels, or more than 100,000 cells of K. brevis per liter of sea water, red tide is considered to be at bloom strength. At bloom strength, the algae is more likely to cause fish kills and irritation in people, including coughing, scratchy throat and watery eyes.

However, local beach conditions have remained relatively pleasant in many areas this week as the worst of the patchy blooms keep offshore. Satellite imagery compiled by the National Oceanic and Atmospheric Administration shows that the most intense areas of red tide are several miles off of Anna Maria Island’s Gulf coast.

Slight respiratory irritation was reported in Holmes Beach on Monday, according to Mote Marine Laboratory’s beach conditions tracker, but it has not been observed since. Beach visitors also posted to social media about experiencing varying degrees of respiratory irritation elsewhere around the island over the last week. However, most people reported still being able to enjoy their time in the sand.

Large, red tide-related fish kills near the shore have not been as prevalent recently as they were over the summer, though smaller amounts continue to be reported. Some dead fish were present on Coquina Beach on Wednesday morning, according to Mote’s beach conditions tracker. FWC also received fish kill reports over the last week from around Holmes Beach and Longboat Key.

Red tide conditions have also improved to the north and south of Manatee County over the last week. In Pinellas County, which had been experiencing high levels of red tide along its Gulf coast beaches, only low to medium levels were observed this week. Very low to medium levels were observed in Sarasota County waters, with the highest concentration of blooms around Longboat and Lido keys.

Red tide weekend forecast

Visitors and residents should expect red tide to linger at bloom strength around Anna Maria Island and Longboat Key over the coming days, according to a forecast produced by the University of South Florida and the Florida Wildlife Research Institute.

Medium algae levels could persist around Anna Maria, Bradenton Beach and Longboat Key, according to the forecast, while conditions may be better in the middle of AMI around Holmes Beach. “Very low” levels are possible along Palma Sola Bay, according to the forecast, and “low” levels of red tide algae could also impact portions of northern Manatee’s coastline.

A respiratory forecast produced by NOAA predicts that respiratory irritation should remain very low around Anna Maria Island and Longboat Key.

This story was originally published October 20, 2021 at 4:10 PM.