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Water Quality Report: Goodbye red tide (for now)

WGCU
After months of red tide blooms offshore of Southwest Florida the waters of the Gulf of Mexico are all clear

WATER QUALITY REPORT FOR JUNE 4, 2023

After a fall, winter, and half the spring with red tides blooms -- on-and-off, on-and-off, on-and-off -- from Tampa Bay south to Marco Island, what you’re going to read next is nothing short of amazing:

Last week there was no red tide anywhere in Southwest Florida.

No respiratory irritation due to red tide.

No smelly dead fish carcasses washed up on the beach en masse.

Just clean, clear, Gulf of Mexico water.

Even the Great Atlantic Sargassum Belt is staying away as you well know, I’m sure, because you read my last Water Quality Report and know the late-for-the-date seaweed was the topic.

Red tides off Sarasota, Charlotte, Lee, and Collier counties were a near-constant fixture since the foot of rain that was produced by Hurricane Ian washed tons of nutrients into the Gulf of Mexico last September.

Much of the nutrient pollution is nitrogen and phosphorus for fertilizers used on front lawns and in agriculture, which don’t create a red tide but do feed it and allow it to perhaps become stronger and last longer than it otherwise would.

Red tides decreased in frequency in the spring, and now, with this week’s Water Quality Report, we know that Hurricane Ian’s bloom doom is over.

RED TIDE:

Florida Fish and Wildlife Conservation Commission reports the red tide organism, Karenia brevis, was detected at background concentrations in one sample, which in one way doesn’t count because K. brevis is endemic in the oceans so it’s always at background levels, just less than background levels if that makes any sense.

No samples above background levels were observed. In Southwest Florida over the past week, K. brevis was observed at background concentrations in one sample from Lee County.

No reports of fish kills suspected to be related to red tide were received over the past week.

Respiratory irritation was not reported in Florida over the past week.

And that, is that.

What is red tide?

Red tide is one type of harmful algal bloom caused by high concentrations of the toxic dinoflagellate K. brevis, which is a type of microscopic algae found in the Gulf of Mexico. Red tide typically forms naturally offshore, commonly in late summer or early fall, and is carried into coastal waters by winds and currents. Once inshore, these opportunistic organisms can use nearshore nutrient sources to fuel their growth. Blooms typically last into winter or spring, but in some cases, can endure for more than one year.

Is red tide harmful?

K. brevis produces potent neurotoxins (brevetoxins) that can be harmful to the health of both wildlife and people. Wind and wave action can break open K. brevis cells and release toxins into the air. This is why you should monitor conditions and stay away from beaches where red tide is in bloom. People in coastal areas can experience varying degrees of eye, nose and throat irritation during a red tide bloom. Some individuals with chronic respiratory conditions like asthma or chronic lung disease might experience more severe symptoms. Red tide toxins can also affect the central nervous system of fish and other marine life, which can lead to fish kills.

What causes red tide?

A red tide bloom develops naturally, but recent studies have discovered mankind's infusion of other nutrients into the mix can make the red tide last longer or get stronger. But biology (the organisms), chemistry (natural or man-made nutrients for growth) and physics (concentrating and transport mechanisms) interact to produce the algal bloom. No one factor causes the development of a red tide bloom.

BLUE-GREEN ALGAE

The National Oceanic and Atmospheric Administration, which has a satellite pointed at Lake Okeechobee that can detect harmful algae blooms found large groups of blue-green algae in the east-center of the lake.

Strong winds from Category 3 Hurricane Irma in 2017 churned up nutrient pollution from the depths of Lake Okeechobee, which helped feed a blue-green algae outbreak that covered 95 percent of the lake’s surface during the summer of 2018.

The much stronger Category 4 Hurricane Ian last September churned up Lake Okeechobee even more, so fears are that this summer will bring a blue-green algae outbreak even worse than the devastating one in 2018.

What is blue-green algae?

Blue-green algae, also known as cyanobacteria, are a group of organisms that can live in freshwater, saltwater or brackish water. Large concentrations, called blooms, can change the water color to blue, green, brown, orange or red. Some cyanobacterial blooms can look like foam, scum, or mats on the surface of freshwater lakes and ponds. As algae in a cyanobacterial bloom die, the water may smell bad

Is blue-green algae harmful?

Different types of blue-green algal bloom species can look different and have different impacts. However, regardless of species, many types of blue-green algae can produce toxins that can make you or your pets sick if swallowed or possibly cause skin and eye irritation. The Florida department of Environmental Protection advises staying out of water where algae is visibly present as specks or mats or where water is discolored. Pets or livestock should not come into contact with algal bloom-impacted water or with algal bloom material or fish on the shoreline. If they do, wash the animals immediately.

What causes blue-green algae?

Blue-green algae blooms occur when the algae that are normally present grow in numbers more than normal. Within a few days, a bloom can cause clear water to become cloudy. Winds tend to push some floating blooms to the shore where they become more noticeable. Cyanobacterial blooms can form in warm, slow-moving waters that are rich in nutrients. Blooms can occur at any time, but most often occur in late summer or early fall.

If any major type of water quality alert is issued, you can find the details here in WGCU’s Water Quality Report.

Environmental reporting for WGCU is funded in part by VoLo Foundation, a non-profit with a mission to accelerate change and global impact by supporting science-based climate solutions, enhancing education, and improving health. 

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