A Preliminary Investigation of Microplastic Levels in a Commercially Important Clariid Fish Species from Ikpoba River, Benin City, Nigeria

Abstract

Microplastics (MPs) in natural water resources and their inclusion in food webs has become a critical issue globally. The paucity of risk assessment data on the levels of MPs in Ikpoba River, Benin City, Nigeria, warranted this research, which was conducted using Fourier Transform Infrared (FTIR) Spectroscopy. The mean levels of MPs in Clarias gariepinus (mean total length 32.74 ± 1.58 cm, mean weight 885 ± 1.76 g) according to stations ranged from 0.37 in June at station 1 to 5.23 in August at station 3, with a total ranging from 2.97 at station 2 to 6.18 at station 3. Significant differences (P < 0.05) were observed in the mean levels of MPs between the months across stations 1 and 3. The mean plastic load in C. gariepinus according to stations ranged from 0.31 in June at station 1 to 6.34 in August at station 3, with a total ranging from 3.22 at station 2 to 7.41 at station 3. Significant differences (P < 0.05) were observed in the mean plastic load between the months across stations 1 and 3. The dominant types of MP particles found in C. gariepinus were fragments and filaments of Polyethylene. The estimated daily intake (EDI) for MPs (No./person/day) ranged from 0.00154 at station 2 to 0.00321 at station 3. C. gariepinus must therefore be consumed with caution in order to avert health problems associated with polymer pollution in the long run.