Microplastics in beach sand and potential contamination of planktivorous fish <em>Sardinella gibbosa</em> inhabiting in coastal waters of Negombo, Sri Lanka

Microplastic pollution has become the most significant marine environmental concern. There been a surge of information on microplastic contamination in various environments worldwide. However, level is just begun to understand Sri Lanka. The present study looked at beach sand Pitipana, Catamaran, and Dūwana beaches along coast Negombo, Sampling was conducted bi-monthly from March November 2017. Beach samples were collected surface (0-1cm) subsurface (10-11cm) layers three regions representing low-tide, high-tide, vegetation line each beach. Sand filtered through 5mm 1mm sieve-set, particles greater than discarded since they are not considered microplastics. Particles retained sieve filtrate separately. Microplastics density separated categorized into two size classes as 1-5mm smaller 1mm. size-class fiber, foam, fragment, pellet. <1mm subjected FTIR spectroscopy identified based polymer type. Further, goldstrip sardine, Sardinella gibbosa obtained coastal waters Pitipana tested for possible commercial fishes. Results revealed that highly contaminated with category microplastics reporting mean abundance (±SD) value 7.2±7.66 particles/m3 by number compared other sites. fragment dominant type found Catamaran beaches, while foam predominant pellets recorded any sites sampled. Polyvinyl chloride (PVC) major sand, polyester beaches. spectra presence polyethylene polypropylene gut contents gibbosa, suggesting planktivorous fish potential accumulation trophic chain.