A Quantitative Analysis of Microplastics in the Gastrointestinal Tracts of Odontocetes in the Southeast Region of the United States.

This article focuses on the characterization and quantification of microplastics—plastic particles less than 5 millimeters in diameter—in the gastrointestinal (GI) tracts of odontocetes (toothed whales) stranded in the southeastern United States and Puerto Rico. Analyzing 30 deceased individuals from six odontocete species, including 24 bottlenose dolphins (Tursiops truncatus), the study found microplastics in 28 specimens, with fibers, white-colored items, and polyester being the most common morphology, color, and polymer type, respectively. The average number of microplastics per stomach was 5.6, while total microparticles (including nonplastic synthetic and natural items) averaged 47.6 per stomach. This research provides baseline data on microplastic exposure in marine mammal apex predators, highlighting the need for standardized methodologies and further investigation into the ecological and toxicological impacts of microplastic ingestion in odontocetes and related marine ecosystems.