Assessment of Microplastic Contaminations in African Catfish (Clarias gariepinus) From Selected Fish Farms in Awka Metropolis, Anambra State, Nigeria
Abstract
This study assessed microplastic contaminations in African catfish (Clarias gariepinus) and water samples from selected fish farms in Awka Metropolis, Anambra State, Nigeria. It also examined the microplastic abundance, particle length, color, morphology, and polymer composition in different fish tissues (gills, intestines, and muscle) and water samples. Microplastic extraction was done using density separation techniques, and polymer identification was conducted using Fourier Transform Infrared (FTIR) spectroscopy. The study also analyzed the physico-chemical parameters of water, including temperature, pH, biological oxygen demand (BOD), and dissolved oxygen (DO). Samples were collected from three commercial fish farms, designated as PF (Farm 1), UF (Farm 2), and HF (Farm 3). The data generated from the study were subjected to statistical analysis. Results obtained indicated significant (P<0.05) microplastic contaminations in all examined fish tissues, with the highest levels found in HF. Specifically, UF's gills showed the highest microplastic abundance (1.23 ± 0.05 particles/g), while PF had the lowest (0.40 ± 0.05 particles/g). In the intestines, HF exhibited the highest concentration (1.14 ± 0.05 particles/g), while PF had lower levels (0.71 ± 0.03 particles/g). Water samples also revealed significant contamination, with HF having the highest concentration (1.37 ± 0.04 particles/L), surpassing UF (0.79 ± 0.09 particles/L) and PF (0.37 ± 0.04 particles/L). Physico-chemical analysis showed significant difference (p<0.05) in environmental conditions among the farms, particularly with phosphate levels being highest in HF (15.58 ± 0.50 mg/L) compared to UF (9.43 ± 0.33 mg/L) and PF (8.48 ± 0.24 mg/L). Other parameters, including temperature and dissolved oxygen, varied notably, with HF often displaying the most extreme values. The presence of microplastics in muscle tissues raises potential health risks for human consumers. The study concludes that microplastic contamination in fish and water samples poses a critical environmental and public health issue. It is recommended that constant monitoring of fish feed and water sources. Also, proper waste management practices should be carried out on a regular basis