If you have been to the Florida Gulf coast you have heard of Red Tide. The harmful algal bloom is the rapid growth of microscopic algae. It generally occurs in late summer or early fall. Along the Gulf coast of Florida and Texas, the algae species Karenia brevis produces toxins that have harmful effects on people, fish, marine mammals and birds. It can result in large fish kills and discolored water. These brevetoxins can become airborne when wave action breaks the cells and can cause severe respiratory irritation in people.
Luckily, Anna Maria Island has not seen severe outbreaks on a yearly basis. Oftentimes the blooms occur in the South Western Gulf of Mexico and don’t travel all the way into our region.
Research of Red Tide
Biologists have documented the occurrence and abundance of K. brevis for more than 50 years, during which detection and monitoring technologies have changed dramatically. The local Mote Marine Laboratory and Aquarium in Sarasota is involved in the Red Tide research program.
Prior to 1970s Florida red tides were believed to originate inshore. Blooms and respiratory irritation were most often observed first around passes and barrier islands. It is now determined that red tides begin in nutrient-poor water 111 to 46 miles offshore. There are 4 stages of a bloom. First is accumulation and spreading into an area. During the second stage growth occurs. The population steadily increases and within a few weeks, K. brevis concentrations may be high enough to kill fish. In the third stage wind and currents control the bloom’s movement. If the algae moves inshore, nutrient runoff from land may promote bloom expansion. A bloom can linger in coastal areas for days, weeks or even months. During the last stage wind and currents disperse the cells. New water introduction reduces the concentration of K. brevis cells.
Scientists are now able to better forecast red tides and their movements. Besides water sampling and enumeration (cell counts), molecular tools and toxin analysis the detection with satellite imagery is a helpful tool. The collected data can be used in predictive models of bloom movement.
The Florida Fish and Wildlife Conservation Commission (FWC) publishes reports on the current status of Karenia brevis blooms using tables, static maps, and interactive Google Earth maps. Please click on more information here. Mote’s Beach Conditions Reporting System provides shoreline observations for public beaches like Manatee County Beach and Coquina Beach on Anna Maria Island. The information is updated as often as twice daily at visitbeaches.org.
The National Oceanic and Atmospheric Administration (NOAA) also issues bulletins that contain an analysis of ocean color satellite imagery, field observations, models, public health reports and buoy data.
Manatee County is also updating daily at mymanatee.org/redtide.
Please contact Team Duncan for more information on this topic. Our office is open Monday through Saturday. We are looking forward to your call at 941 779 0304 or send us a quick message here.