Tuesday, November 30, 2021

When Did Red Tide Start? How Does it Affect Us and Our Wildlife Friends?

Rumination from the Rock and Beyond


For the last several years, we’ve all heard the warnings about Red Tide and the consequences from exposure, but the one thing I’ve wondered is when did Red Tide begin? What started it? And what is the prognosis for the future of Florida? With those questions in mind, I started researching to find the answers, which I’ll share with you as it’s very interesting.  

Photos by Jory Westberry | The majority of the fish I checked were catfish, but there were also redfish.

Historically, fish kills near Tampa Bay were mentioned in the records of Spanish explorers as early as the 1500s and documented in the 1700’s, again near Tampa Bay. There were also reports of dead fish along Floridas Gulf Coast into the 1840’s. Red tide is not a unique occurrence. It seems unique to all the recent residents and visitors to SW Florida, but the phenomena really goes back many years. During Hurricane Katrina in 2005, the red tide was followed or pushed up into the Panhandle.  

In the last few years, there have been many alerts about red tide, some very alarming/dramatic and some not, but the question still remains: What is it and how does it affect us and the marine life that surrounds us? Sadly, the duration of the algae bloom can last weeks or (shudder) years and can come and go. It actually appears in reddish patches or stream-like swathes in the Gulf waters, hence the name Red Tide. 

The algae will bloom at certain unpredictable times and intermittently. The Karenia brevis algae produce neurotoxins that can affect persons with respiratory issues such as asthma or COPD, and they may encounter a scratchy throat, coughing, sneezing and watery eyes when near the source of the algae. The side effects from red tide can cause eye and lung irritation, especially with persons with respiratory issues. It’s recommended that people with these concerns should stay away from the coastlines and water sports during the bloom.



Usually a lovely place to dine with a great view in the Villages at Venetian Bay, but…

Another factor to consider with red tide is the danger of eating shellfish that are harvested from identified, restricted areas during a red tide bloom. Because they may have been contaminated by the micro-algae of red tide, eating oysters, mussels or clams can cause NSP or Neurotoxic Shellfish Poisoning, which has nasty symptoms including trouble walking, diarrhea, difficulty breathing, and vomiting (no thank you)The Florida Department of Agriculture and Consumer Services is a great resource because they monitor and test shellfish beds and close those areas identified as unsafe. 

Luckily there are other resources to help. Signs are posted at beach entrances that warn the public when red tide is identified along with advice to those with respiratory sensitivities. Also, the Florida Fish and Wildlife Conservation Commission’s red tide status website iresource. 

Recently, red tide killed off huge numbers of fish up and down the southwest coast. It was particularly smelly on the Isles of Capri with the high tide bringing the dead fish into the mangroves and canals and leaving them there until the next high tide either takes them back out or adds more to the piles. The smell almost knocks you off your feet. The Isles has a large community of walkers and bikers, but during an outbreak like this, you would have to mask up and put a clothespin on your nose! 

Occasionally, I’d see a very dead fish that looked like a bird took a bite out of it, but it was only one bite. This made me question whether the fish tasted nasty or did the red tide also affect the bird? What are the ramifications if our local birds are affected? What about our resident dolphinsmanatees and sea turtles? There have been reports of their susceptibility to red tide and their corpses have washed up on the beaches. 

There doesn’t seem to be a strategy to predict, limit or treat the algae bloom called red tide, but research continues. It’s healthy to know about it so you can take the precautions needed to prevent the side-effects which, for our older population, can be quite worse and long-lasting. Stay safe. 



2 responses to “When Did Red Tide Start? How Does it Affect Us and Our Wildlife Friends?”

  1. You ought to read A Toxic Inconvenience: Red Tide and Blue-Green Algae on Florida’s Coast. It’s a complete history of red tide with some thoughts about how to deal with it – available at Amazon.com in Kindle or paperback.

  2. Carol says:

    Does your history of red tide show that March will have red tide at Marco Island too? Are there any months where the chance of red tide is very low, especially at Marco Island?

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