What Is Going On With Red Tide On Florida’s Coast? – Part 3 From Rose Lipke
At this point we know our water quality in Florida has been declining for some time, both inland and along our coasts. Just in my lifetime I have seen the bays and Gulf waters change slowly over time. I have watched our seagrass beds shrink and completely disappear in some places. I have watched our mangrove fringed shoreline be replaced with houses and condos and businesses. Where once there were thriving scallop populations, today they are all but gone. It’s the same story for clams and good oyster beds, leopard and spotted eagle rays just to name a few. The water in the bay used to only get murky in the deep summer months, when the shallower grasses naturally die off from the rising water temperatures and decay, adding their nutrients to the natural rhythm of the bay. And then there is red tide.
When you live near the water you know it well. Blooms come and go driven by winds and tides. Some years were worse than others, some years your stretch of paradise was spared. About one year in 10 there would be a particularly bad outbreak. I remember one in the 70’s that hung around so long that my aunt and I went and stayed in a hotel in town, since she suffered from asthma and I have always been particularly sensitive to the airborne toxins. The bloom of 2001/2002 was another memorable outbreak. The fish stacked up in marinas and canals so thick it seemed you could walk across them. What I don’t remember from any of those blooms were mammal deaths. You never found a washed up dolphin, manatee or sea turtle. Surface breathing mammals suffer from the same respiratory symptoms that you and I do. By and large they move away from the areas where the bloom is present and go along their merry way. If you did find a fatality there would most likely be a contributing factor, such as injury or illness already present. This has not been the case in the past 6 or 7 years. Every year the number of deaths in these populations rise, from just a few each year, to absolutely staggering numbers in 2018.
So what is so different now?
Karenia brevis, the organism responsible for red tide blooms, feeds on the same thing all algal species do. Phosphates and nitrates, present in high concentrations in agricultural, stormwater and urban runoff are the perfect food. The more food present in the environment, the larger, stronger and longer the blooms become. Study after study have been done regarding this correlation with consistent and reliable results.
THE PERFECT STORM
A persistent low level red tide bloom had been floating off the coast of southwest Florida since November of 2017. It would blow in to shore occasionally causing minor fish kills and move back off. Pretty typical for a red tide bloom. In late June and early July, as the rainy season hit, so began the annual discharges from Lake Okeechobee into the Atlantic and Gulf coastal waters. At the same time toxic blue-green algae was amassing in canals and tributaries along the Caloosahatchee River, causing fish kills of their own. The dark plume of nutrient laden lakewater made its way into the Gulf of Mexico and right into the arms of the awaiting red tide. Within a few short days the bloom exploded, with concentrations reaching a staggering 5 million cells per liter. Fish kills happen when concentrations of red tide reach just 10,000 cells per liter.
The islands of Sanibel & Captiva near the mouth of the Caloosahatchee, Boca Grande to the north and Ft. Meyers beach to the south became covered with dead sea life. Giant goliath groupers, dolphins, sea turtles, even a small whale shark washed up with each incoming tide. One member of the Caloosa Waterkeepers described it as as a biological explosion, killing everything in its path. It didn’t end there. The bloom grew in size without losing any of its toxicity, south into Collier County and the Naples area, and north into Charlotte Harbor where one manatee was rescued after being found in a state of paralysis, clearly a neurological reaction to the high concentration of potent collection of neurotoxins produced by red tide collectively called brevetoxins. And it kept growing. Further north into Sarasota county, Manasota Beach, Venice and Casperson’s beach lay covered with dead, rotting marine life. Bays and canals filled with dead fish large and small. Bait fish, sand eels and game fish, even seabirds began collecting in canals and the backside of the barrier islands.It steadily moved north to Turtle Beach and Siesta Key, closing Siesta beach for the first time that I can remember. Driving up Longboat Key to Sarasota on Sunday, the Key was a ghost town and the smell of red tide and rotting fish on Lido Key and St.Armand’s Circle was unbearable.
Today the bloom stretches over 100 miles from the north end of Anna Maria Island in Manatee County and extends into the Gulf over 10 miles in some places. A prevailing east wind over the past week has abated it somewhat in some areas, moving it offshore a bit, but levels are still in the medium to high ranges in most places. A shift in the wind can change that at any moment, and since we are still in the rainy season the possibility of more discharges is ever present. The forecast from the FWC (Florida Fish and Wildlife Commission) is for more northwestern movement of the surface waters, possibly affecting Pinellas County beaches in the coming week. To date sea turtle deaths have reached a staggering record of over 400 and rising. The previous record was set in just 2014. Manatee deaths attributed to red tide have reached 189, with 109 of them occurring in Lee County alone. I have been unable to find reliable numbers on dolphin deaths, yet as I was researching a live news alert hit my phone that Venice Marine Patrol were removing two dolphins, both suspected red tide deaths, from the boat ramp at the Venice jetty. One was an adult, the other a juvenile.
The FWC (Florida Fish and Wildlife Commission) also predicts this bloom can stay with us right into 2019. That would make this single bloom over a year old.
One thing is for certain, this is not our parents red tide anymore.
Photos courtesy of Erin Brockovich FB page, Google earth, and Wikipedia