The storm will have a short term & long term impact on red tide along the Gulf Coast. The onshore winds will bring dead fish & respiratory irritation to some beaches in southern Tampa Bay & Fort Myers area.
➡️ Hurricane Ian set the stage for red tide to start developing about a month ago off the coast of hard hit Fort Myers & Sanibel. An abundance of nutrients (nitrogen, phosphorus, etc) were washed into the Gulf via storm runoff. Karenia brevis (aka red tide) feeds on these nutrients has been expanding in recent weeks.
➡️ The mainly offshore bloom has nearly doubled in size over the past 10 days.
➡️ There have been reports of dead fish washing ashore in southern Sarasota & Charlotte counties.
➡️ Predominantly easterly winds over the past few weeks have kept the majority of the red tide bloom & dead fish offshore.
SATELLITE IMAGE:
➡️ The satellite image in this post shows solar stimulated chlorophyll-a fluorescence, which when combined with water samples, we know to show karenia brevis (red tide).
➡️ Where you see red in the Gulf of Mexico, then fish are likely dead. The red & yellow represent medium to high levels of karenia brevis. How lethal the bloom is to marine life depends on the concentration & depth of red tide.
SHORT TERM:
➡️ Winds circulating counterclockwise around #Nicole will bring an onshore fetch (aka westerly wind) to the Gulf Coast.
➡️ Westerly winds will push the surface red tide bloom toward the nearby beaches.
➡️ The bloom is fairly large offshore of Southern Sarasota, Charlotte & northern Lee Counties, so you can expect considerable respiratory irritation & dead fish washing ashore on Thursday & Friday in this vicinity (mainly between Sanibel & Sarasota).
➡️ The bloom may also migrate north & have an impact on northern Sarasota (& possibly Manatee) County beaches.
➡️ Winds will continue to blow onshore through the weekend due to the impact from Nicole & then a cold front.
LONG TERM:
➡️ Rain with Nicole will not be as heavy as it was with Ian, but it will add additional nutrient laden runoff in the days following Nicole.
➡️ Red tide could INCREASE over the coming weeks/month... because the additional nutrients will provide "food" for karenia brevis to proliferate & spread.
➡️ Red tide could DECREASE over the coming weeks/month.. because the rough seas with Nicole will mix & dilute the karenia brevis dinoflagellates. Fresh water runoff could reduce Gulf salinity making it a less favorable environment for red tide.
➡️ So, the status of red tide in the Gulf in early December will depend on whether the increased nutrients or diluted water provides a more hospitable environment for the harmful algae bloom.
➡️ As we move into January, the Gulf temperature will drop & runoff will be reduced due to less rainfall. This combination could help reduce or eradicate a potential bloom.
➡️ Stay tuned. Forecasting red tide is a complex science. So, I'll continue to monitor & provide updated satellite images once the storm has passed.
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