This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Microplastics are turning up almost everywhere—from oceans and rivers to soils and sediments—yet far less is known about what happens when they enter freshwater wetlands. Often overlooked in favor of marine and coastal environments, wetlands can act as both pathways and traps for microplastics, potentially capturing and retaining pollution.
That knowledge gap is particularly important in small, urban-adjacent wetlands throughout Florida, where stormwater runoff, recreational activity and connections to rivers and other waterways can introduce microplastics. Yet little is known about how these particles move and accumulate within these ecosystems. To help fill these gaps, Florida Atlantic University researchers examined microplastics at Spruce Bluff Preserve, a 97-acre (39-hectare) freshwater wetland along the St.
The study provides the first detailed look at how microplastics are distributed across the preserve and how vegetation, sediment composition and proximity to water influence where particles accumulate. Researchers collected 40 surface sediment samples from eight transects spanning different ecological zones. Samples were collected every 5 meters (16 feet) in December 2024 during the dry season, and researchers recorded each site's distance from water.
They also used infrared spectroscopy to confirm a subset of particles, providing a more accurate estimate of microplastic abundance. Results of the study, published in the journal Evolving Earth, reveal that microplastics were found throughout Spruce Bluff Preserve and were detected in 38 of 40 sediment samples (95%) across every ecological zone. Most of the confirmed particles were tiny—about 88% were smaller than 2.5 millimeters—and nearly half were fibers, suggesting that synthetic textiles and other everyday materials may be contributing to plastic pollution in the preserve.
But the particles were not distributed randomly. The highest concentrations were found along the St. Lucie River and an outlet canal used for flood control, suggesting that water movement is helping transport and concentrate microplastics within the wetland.
"Perhaps the most striking finding is that the microplastics weren't simply scattered randomly across the preserve—they appeared to follow the pathways of water," said Erik N. Johanson, senior author and an associate professor in the Department of Geosciences within FAU's Charles E. Schmidt College of Science.
Extract — continue reading at the source.
