Red Tide Prediction and Tracking on the West Florida Shelf - Southeast Coastal Ocean Observing Regional Association
Original (non-English) name
Acronym
Red Tide Prediction and Tracking on the West Florida Shelf - SECOORA
Citation
Abstract
The College of Marine Science, University of South Florida (CMS-USF) provides seasonal predictions of major red tide events and short-term tracking of red tide once an event occurs. Seasonal prediction follows from the recognition that Karenia brevis red tide, of offshore origin, thrives under the low nutrient conditions generally found in the middle of the west Florida continental shelf (WFS). Conditions in successive years are generally not alike. When deeper ocean currents influence the WFS in certain ways, nutrients may be upwelled onto the WFS and carried toward the shore. If this occurs in spring to summer months, when K. brevis blooms tend to form offshore, other faster growing microscopic plants can prevail over the slower growing K. brevis, thereby suppressing red tide bloom development. By keeping track of Gulf of Mexico currents, we can account for the occurrence or lack of major red tide blooms for 20 out of 25 years in which concurrent ocean currents and red tide data are available. As examples, 2010 experienced no red tide, 2012 was severe, whereas 2013 was only nominal. All subsequent years experienced major blooms, although 2016 provided an outlier, a year when we thought that there would not be a major bloom when one indeed occurred.
Once a bloom occurs, the Florida Wildlife Research Institute (FWRI) conducts K. brevis sampling and provides cell count observations to the CMS-USF team. The USF team then inputs these into an ocean circulation model to forecast where these cells may go over the next 4.5 days. With the cell counts a day old when received, the forecast consists of a 1-day hindcast followed by a 3.5-day forecast using our daily, automated West Florida Coastal Ocean Model (WFCOM). The "X" represents the starting point where each sample was collected. The lines show the 3.5 day trajectory for each sample. The color represents the red tide concentration for each sample. Black lines are not indicative of red tide; instead, they show where the current would take a simulated buoyant particle. These may be useful for search and rescue, or for tracking hazardous spills. The short-term red tide trajectory forecast products (uppper and lower water columns) are updated daily in the early morning. Similar products have been developed for the Tampa Bay region using high resolution ocean circulation model.
Given the short-term forecasts and the recognition that the spatial sampling is limited, blooms may be patchy, and trajectory forecasts include errors, we further produce a more general and user-friendly map to show where a red tide bloom may occur along the coast over the next several days. This product is updated every Wednesday and Friday.