
Native Floridians have struggled adapting to life as the timeless quality and charm of old Florida are being lost as a result of overdevelopment. That same overdevelopment contributes to the factors that support red tide’s continual growth. Many of us suffer from climate change grief — in particular, the loss of something in nature in the places we have lived so long.
Red tide was once only a rare and brief inconvenience in Florida. While red tide is natural, Boomers remember when natural red tide blooms were barely a blip in the overall Florida experience, compared to what seems to be an ever-present nuisance these days. My maritime friend, like myself, remembers those decades before. She has made a living in the waters of the Gulf. She tells me it may be here all summer this year — and why. It is a much more frequent encounter caused phosphate mining runoff, inflows of nitrogen, and man-made fertilizer feeding the blooms. These problems have arrived concurrent with ocean acidification and all kinds of toxic runoff (from overdevelopment) into the beautiful Gulf of Mexico, including the effects of last year’s major hurricane.
The Great Atlantic Sargassum Belt

The jet stream changing, along with the corruption of the her once pristine gulf waters, yet old Florida’s beauty is protected on my dear friend’s watch
Now, along with other crises, Floridians are watching the Great Atlantic Sargassum Belt, with its 5,000-miles reach, as it engulfs the waters around Miami and Key West, the most quintessential of old Florida, and extends into the Gulf of Mexico.
NPR reports that the algae known as sargassum “is leaving stinky brown carpets over what was once prime tourist sand.” And it is the largest amount that sargassum researchers have tracked this early in the year. The tangled web is woven throughout the ocean from Africa to Miami, but its thickening webs have gotten much more dense as the oceans have warmed — though, seemingly not because of the oceans warming. There are connections, however.

Too much sargassum can present challenges for marine life, and particularly becomes a problem when it collects along coastlines and rots, as shown here in Cancun in 2015. Photo credit: Michael Owen, courtesy of NASA.
Last summer, the The Smithsonian Institution’sDanielle Hall questioned, “Why the sudden increase of sargassum?” They reported: “Scientists suspect it is a combination of changing ocean currents due to climate change and an increase in nutrient input from Amazon deforestation that is causing the perplexing explosion of growth.”
The algae does benefit birds, some ecosystems, and marine life in the open ocean. Sargassum provides habitat for turtles, crabs, fish, and birds, and by producing oxygen via photosynthesis. However, when it reaches shores, its tangled dark webs have a negative effect on crucial ecosystems such as those of bays, gulfs, and shores.
Hall continues: “Normally, sargassum is a considered a nursery habitat for juvenile sea turtles and fishery species like gray triggerfish, amberjack, and Mahi when it is in the open waters.” Once simply an oasis for ocean life, though, “now it is a nuisance.”
“Too Much of a Good Thing—the Atlantic Sargassum Belt” depicts the Amazon River’s severe flooding in 2009 as one cause, as it deposited the most nutrients into the ocean in 30 years. (And flooding is a cause that keeps on coming.)

The Great Atlantic Sargassum Belt, July 2011–July 2018. Image courtesy of NASA.
Smithsonian’s Hall continues: “Is this the new norm? According to scientists, due to changes happening to the climate the Sargassum blooms are likely to stay. The Amazon River is a powerful force that effects the ocean and it is changing due to human activity. At the turn of the century extreme flooding of the Amazon River occurred every 20 years—now it happens on average every four. From 2009 to 2015 severe flooding happened every single year. Additionally, deforestation is adding to excess nutrients flowing into the ocean. When forests are chopped down and burned the nutrients and the soil are flushed into the ocean. The farms that take the place of the forests add nutrients as fertilizer runoff. ”
Sargassum Patch This Year
Video by Ellen Park © Woods Hole Oceanographic Institution, via YouTube
Earlier in March, PBS NewsHour quoted Chuanmin Hu, a professor of oceanography at the University of South Florida: “Some sargassum has already reached beaches in Key West, Hu said, But most of it will arrive in the summer. ‘What is unusual this year compared to previous years is it started early,’ Hu said. The algae generally blooms in the spring and summer, but ‘this year, in the winter, we already have a lot.'”
Scientists are working hard to uncover the downsides and possible upsides of the changing patch. Researchers are pushing themselves and must be innovative, and that requires getting inventive with masses (tons) of densely braided, rootless algal blooms. For the moment, ideas are in the early phases, and April’s record could double by July 2023.
A bulletin from the University of South Florida Optical Oceanography Lab shares the outlook for the summer and that the overall belt is growing toward an estimated 13 million tons.