Paradise under pressure: Microplastics threaten Florida's Gulf Coast waters

Tiny pieces of plastic are turning up across Gulf Coast waters, raising concerns among scientists and wildlife experts about the growing threat microplastics pose to marine life and human health.

Capt. Colleen Gill, who runs wildlife tours through Florida Adventures, sees the impact firsthand every day on the water.

"I consider myself to be one of the luckiest people in the world to be able to do this every day," said Gill, who runs wildlife tours through Florida Adventures.

Out on the water, Gill recognizes dolphins the way neighbors recognize familiar faces. There's "Flat Top," a dolphin she says knows her boat well, and "Penny," identified by a notch in her fin.

"These guys are like my little free-range cousins," Gill said. "These are all my family right here."

Gill says the dolphins even recognize the sound she makes using the trim on her boat motor — often swimming directly toward her vessel after hearing it.

But amid the beauty of Southwest Florida's coastline, Gill sees a growing problem every day: pollution.

"One thing I hate to say, but it's true, is so many of these animals, like manatees and dolphins, don't really have many natural predators," Gill said. "Humans have become one of their biggest predators."

Scientists say the most dangerous pollution is often invisible.

Microplastics — tiny plastic particles created when larger plastics break down — are now found in oceans around the world.

"There are microplastics all around us," Gill said. "Not a single mile of ocean does not have plastic anywhere worldwide."

To see how widespread the problem is along Florida's Gulf Coast, we collected water samples from several beaches and had them analyzed at a Florida Gulf Coast University lab led by researcher and professor Dr. Pupsa Adhikari.

Students filtered the water samples before examining them under a microscope, counting individual plastic particles one grid at a time.

The results that FGCU students Lauren Shea and Isabel Kacprowski found showed microplastics in every sample tested.

Researchers found 67 microplastics in one liter of water collected at Fort Myers Beach, 32 in Englewood, and 17 on Marco Island.

The highest concentration came from Sanibel Island, where nearly 250 microplastics were found in a single liter of water.

Adhikari said many of the particles appeared to come from synthetic clothing fibers released during washing.

"It looks like it is mostly either from laundry or clothing," Adhikari said.

Microplastics are increasingly being detected not only in oceans, but also in food, drinking water and even the air.

"The nanoplastics are even in the human brain, which is definitely scary," Adhikari said.

Research has shown that the average person may consume the equivalent of a credit card's worth of plastic each year through food and water.

And once microplastics enter the environment, removing them becomes nearly impossible.

"The problem with microplastics is once they are in water, it's almost impossible to get out," Adhikari said. "To clean our ocean is almost impossible. So reducing microplastics produced at the source is the best way."

Gill said the effects are already changing the natural world.

While on a tour, she found a discarded plastic cup covered in egg casings from whelks, a type of sea snail.

"It was really sad to see that they're actually now utilizing things like this as a way to attach their eggs," Gill said.

For Gill, this is exactly why she continues taking people out on the water every day.

"Our goal in these tours is to make people fall in love with this ecosystem," she said. "Because if you fall in love with something, you're going to want to protect it."

Analyzing the data

Water samples from various parts of Southwest Florida beaches reveal that microplastic pollution is widespread across the region, with microplastic particles detected in all the samples, including Sanibel, Fort Myers Beach, Englewood Beach, and Marco Island.

Counts ranged from as low as ~10 particles at some sites to over 250 at others, with fibers making up nearly three-quarters (~73%) of all microplastics, pointing to common sources such as laundry, clothing, and wastewater.

Smaller contributions came from beads (~14%) and fragments (~12%). Notably, Sanibel showed the highest concentrations, with Fort Myers Beach also exhibiting elevated levels.

These findings highlight that microplastic contamination is not confined to isolated areas but is a pervasive environmental issue along the Southwest Florida coastline, raising concerns about impacts on marine ecosystems and potential human exposure.

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