Microplastics have been found in the gastrointestinal (GI) fluid of bottlenose dolphins (Tursiops truncatus), inhabiting Sarasota Bay, FL, suggesting exposure by ingestion, possibly via contaminated fish. To better understand the potential for trophic transfer, muscle and GI tissues from 11 species of dolphin prey fish collected from Sarasota Bay were screened for microplastics (particles <5 mm diameter). Suspected microplastics were found in 82% of muscle samples (n=89), and 97% of GI samples (n=86). Particle abundance and shapes varied by species (p<0.05) and foraging habit (omnivore vs. carnivore, p<0.05). Pinfish (Lagodon rhomboides) had the highest particle abundance for both tissue types (muscle: 0.38 particles/g; GI: 15.20 particles/g), which has implications for dolphins as they are a common prey item. Findings from this study support research demonstrating the ubiquity of estuarine plastic contamination and underscore the risks of ingestion exposure for wildlife and potentially seafood consumers.
Keywords: One Health; bottlenose dolphin; contaminant; plastic pollution; trophic transfer.