Assessing the State of Microplastics Pollution Levels in Fishes and Fishing Grounds in Cabo Verde using Microscopy and Hyperspectral Imaging System Technique

Abstract

Microplastics (MP) have been extensively studied for their detrimental environment effects. This study investigates the occurrence and distribution of MP in selected fish species and fishing grounds near São Vicente, Cabo Verde, utilizing microscopy and hyperspectral imaging (HSI). The results demonstrated a prevalent presence of MP particles, with fibers being the most abundant shape and a significant proportion of MP appearing black. MP distribution patterns in shape and color were similar across all stations, indicating no specific aggregation. While Mindelo 1, São Pedro, and Calhau fishing grounds exhibited comparable MP concentrations, Mindelo 2 had higher levels. Approximately 51% of fish samples showed MP ingestion, with Caranx crysos exhibiting the highest abundance. Fish did not demonstrate selectivity based on shape or color, suggesting ingestion based on availability. No significant adverse effects on fish growth conditions were observed despite MP ingestion. Polymer analysis revealed two prominent groups, Polyethylene (PE) and Polypropylene (PP), indicating potential sources from inadequate waste management by individuals as well as fishing activities. However, limitations of the study include the HSI system's inability to analyze black and white samples. Further research without such limitations is necessary to comprehensively understand MP pollution in the study region.