Microplastics contamination of fish from the creeks along the Kenya coast, Western Indian Ocean (WIO)

Abstract

Microplastics (MPs) are a global threat to marine life, but information available on the extent of pollution along the Kenya Indian ocean coast is absent. Ingestion of MPs by five common pelagic fish from the region was investigated in this study. Fish tissues were digested in 10% potassium Hydroxide (KOH) at 60°C for 14 h and the MPs separated by floatation method using supersaturated Sodium Chloride (NaCl) solution. The benthic fish studied (Acanthopagrus berda with a mean of 0.48 ± 0.06 MPs per gram (g-1) tissue, Gerres oyena 0.20 ± 0.02, Terapon jarbua 0.20 ± 0.06) had higher MPs contamination compared to the pelagic (Rastrelliger kanagurta 0.054 ± 0.011) and reef fish (Leptoscarus vaigiensis 0.038 ± 0.009) reflecting the influence of habits and habitat on MPs contamination in fish. Fish caught in the second sampling had higher MPs contamination compared to the first and fish from Mida Creek had higher MPs contamination compared to those from Tudor and Port-Reitz probably because they were mainly benthic fish. Gut and gills of all species contained significantly higher concentrations of MPs than the flesh. Thus, we recommend that fish be gutted and thoroughly clean the gills before cooking to reduce MPs contamination. There is need for further research to evaluate the risk posed to humans by the consumption of marine water fish that ingested MPs.

Keywords

• microplastic contamination
• fish
• creeks
• western indian ocean kenya coast