Red Tide Update: Robots Help Researchers, Forecasters Monitor Bloom

Underwater robots “Waldo” from Mote Marine Laboratory and “Bass” from the University of South Florida (USF) have been hard at work monitoring the offshore bloom of Florida red tide and surrounding ocean conditions since they were deployed on Aug. 1. Their results are helping shape short-term bloom forecasts.

The bloom was recently reported to be 80 miles long and 50 miles wide, reaching from Dixie County to southern Pasco County, according to the Florida Fish and Wildlife Conservation Commission’s (FWC) statewide update on Aug. 1.

Robot results:
During the past few days, the robots have reported:

  • Waldo: At 40 miles from the Pasco/Hernando border, red tide was detected at the surface and to depths of about 25 meters (82 feet) in areas where it was indicated by satellites.
  • Bass: At the outer edge of the bloom, elevated chlorophyll associated with the red tide was present in waters as deep as 40 meters (131 feet).
  • Both: The bloom water is “stratified” (layered) with denser, cooler water below and lighter, warmer water on top.

Waldo will complete his mission this week or early next, while Bass will finish in two to three weeks.

The robots’ data are feeding into short-term forecasts of the red tide bloom developed by the Collaboration for Prediction of Red Tides, a partnership effort between the Florida Fish and Wildlife Conservation Commission (FWC) and USF.

Forecast findings:
The latest three-day forecasts from USF and FWC, informed in part by the Mote-USF robot missions, show:

  • The surface water in the bloom region is expected to move slightly south, but move little overall.
  • The deep water in the bloom region is expected to move southeast slowly.
  • These south and southeast movements could bring the bloom close to southwest Florida’s coast in the coming weeks. However, there are many variables. For instance, large weather systems passing through can break up blooms.
  • According to the National Oceanic and Atmospheric Administration, no respiratory irritation is expected at southwest Florida beaches through Aug. 11.
  • At this time, Mote scientists encourage Florida residents and visitors to remain informed and follow scientific findings closely. (Scroll down for red tide links and resources.)

Other updates from scientists in the field:

  • FWC cruise with Mote and USF scientists on board: FWC, Mote and USF scientists have been collecting many kinds of data about the bloom during an FWC-led research cruise aboard the R/V Bellows, wrapping up today, Aug. 6 The goal is to construct a 3-D picture of the red tide by measuring concentrations of red tide algae in surface and deep waters offshore of Pinellas, Pasco, and Hernando counties.

    Mote scientists on board are using state-of-the-art technology — including a Mote-developed red tide detector called an optical phytoplankton discriminator, nicknamed "BreveBuster" — to learn more about the red tide alga Karenia brevis and its relationship to the dynamic community of other microscopic algae found in Gulf waters. The Mote researchers are studying phytoplankton pigments to study other species in addition to K. brevis. FWC is defining the nutrients present, and studying DNA and the phytoplankton community. USF scientists are studying optical properties of the bloom: ways that algae reflect the light. This is important for ground-truthing satellite images.
  • Results from Mote’s water samples on July 31: Mote’s water sampling trip last Thursday, July 31, helped document red tide presence and intensity for FWC’s statewide report on Aug. 1. Mote samples revealed medium concentrations of red tide algae at some sites offshore of Pasco and Hernando counties — a region in the thick of the bloom. Mote also sampled waters between Sarasota and the bloom’s southern edge, finding that many sites lacked red tide or only had background concentrations. However, sampling confirmed low and very low concentrations of red tide algae about 33 miles west of Caladesi Island in Pinellas County. (For definitions of bloom concentrations, scroll to the bottom of FWC’s report.)

    It’s important to note that sampling is tricky: Red tide blooms can be very patchy, and areas with few red tide cells can be close to areas with lots of cells. The cells can even swim and clump together. That means scientists must take multiple samples to get the best possible understanding of bloom intensity.

Partnership efforts: 
Mote, USF and FWC’s Fish and Wildlife Research Institute and others who study Florida red tide are partners in a major environmental monitoring collaboration called GCOOS – the Gulf of Mexico Coastal Ocean Observing System. GCOOS provides timely information about the environment of the U.S. portion of the Gulf of Mexico and its estuaries for use by decision-makers, including researchers, government managers, industry, the military, educators, emergency responders and the general public. Both gliders are reporting data to GCOOS’s Data Portal ( in support of these efforts.

Red tide resources:
Statewide red tide updates and info from FWC
Statewide updates in the HAB Bulletin from NOAA
Red tide information from Mote, including FAQs and the Beach Conditions Report: a monitoring system for red tide impacts on multiple Florida beaches
Follow robots Waldo and Bass. The public can see Waldo’s position by clicking “Glider Operations”
Learn about red tide on Facebook from this FWC-Mote page about Florida’s harmful algal bloom
Latest model forecasts from USF-FWC Collaboration for Prediction of Red Tides