Sahyadria chalakkudiensis, the endemic barb inhabiting rivers of Western Ghats, S. India has been supporting considerable aquarium trade and is known to dwell in upstream areas of these rivers. A concerted study on its feeding biology from 730 fishes has revealed consistent occurrence of microplastics in their guts, pointing to serious plastic pollution affecting riverine ecosystem. This fish has omnivorous feeding habit as evident from percentage index of relative indices of various prey items as animal matter (62%), filamentous algae (26%), sand particles (4%) and other matter (8%). Among other matter, microplastic fibres were consistently encountered in 86 guts (11.8% of total guts examined) collected in all months except September. The monthly occurrence of guts containing microplastic fibres showed significant correlation to guts containing filamentous algae (r=0.95, p<0.05). Further, the mean s.d of frequency occurrence of guts with microplastic fibres differed significantly between seasons being lowest in pre-monsoon (3 1guts) and highest in post monsoon (11 5 guts). However, the occurrence of microplastic fibres was not influenced by feeding intensity which indicated that the fish consumed these microplastic fibres inadvertently. The number of microplastic fibres encountered in each gut varied from 1 to 4, however, guts with one fibre only outnumbered others in all seasons. The present results indicated possibility of micro-litter ingestion during feeding from sediments and from shallow stagnant areas in rivers. The paper discusses challenges of aquatic pollution by plastic litter caused by anthropogenic interventions in protected forest areas and suggests mitigation strategies.
