Temporal variability of microplastics in shrimp (Litopenaeus vannamei), feed, water and sediments of coastal and inland culture ponds

Aquaculture, particularly shrimp farming, is crucial for global food security. However, the increasing presence of microplastics (MPs) in marine environments, shrimp feeds, and atmospheric particles has made MP contamination in shrimp tissues inevitable. This study systematically investigates the abundance, characteristics, and temporal trends (from 15th to the 120th day of culture) of MPs contamination in Litopenaeus vannamei, along with associated feed, water, and sediment across 12 shrimp ponds of two major shrimp-producing regions of India. MPs were detected in 93.7 % of shrimp samples and all environmental matrices, with the highest abundance recorded in coastal culture ponds. The overall average MPs abundance in shrimp was 4.07 items/individual (1.24 MPs items/g). MP sizes ranged from 8 μm to 4.22 mm, with MPs smaller than 100 μm being predominant in shrimp samples, though their prevalence decreased over the culture period. Fragments and fibers were the dominant morphotypes across all matrices, with a shift towards larger MPs and an increased proportion of fibers and films over time. Micro FTIR analyses revealed polyethylene (PE) and polypropylene (PP) were the most common polymers detected, indicating their widespread environmental distribution. Feed was identified as the primary source of MPs contamination in shrimp. The presence of MPs in shrimp raises significant concerns for consumer health, food safety, and trade, as shrimp are among the most widely consumed aquatic food products. This study underscores the dynamics of MP contamination in shrimp aquaculture and highlights the urgent need for targeted strategies to mitigate contamination, ensuring consumer safety and industry sustainability.