Microplastic pollution in Surabaya River Water and Aquatic Biota, Indonesia

Abstract

Microplastics (MPs/MP) have been considered as an emerging environmental threat worldwide. It occurs due to its persistent, ubiquitous presence, and potential ecotoxicological risks to almost all aquatic environments. The MPs could release chemical additives and adsorb persistent organic pollutants. It could also be ingested mistakenly by aquatic biota due to its similarity with their original prey’s size and colour. This situation could impact water resource quality, aquatic biota biodiversity, even human health. Additionally, rivers have been estimated as the main pathway of plastic transport from the land to the ocean. Surabaya River, is the main lower part of the Brantas, which is one of the top 20 plastic polluted rivers globally. The Surabaya River takes essential role in clean water supply for Surabaya City, aquatic biota habitat, and irrigation. This study aimed to investigate the distribution and characteristics of the MPs in water and aquatic biota in Surabaya River. Fish and bivalve were selected as the representative aquatic biota due to their specific habitat, movement, and feeding behavior. Water and biota samples were collected from five sampling sites in the river. The MP abundance in the water ranged from 9.66 ± 8.87 to 21.16 ± 19.35 particles/m 3 . The highest MP abundance (21.16 ± 19.35 particles/m 3 ) was found at Joyoboyo. The MP abundance in the fishes of Oreochromis niloticus, Barbonymus gonionotus, and in the bivalves of Elongaria orientalis were 105.25 ± 45.07 – 155.50 ± 61.96; 62.13 ± 20.33 – 155.00 ± 81.71; and 36.00 ± 13.67 – 76.17 ± 29.46 particles/individual, respectively. The MPs in the water were dominated by film shaped, transparent coloured particles. Meanwhile, the MPs in the fishes and the bivalves were generally found in transparent and black fiber particles. Only small amounts of film particles were discovered in the biota. Moreover, most of the MPs in the water and the biota were in large sized (1 – 5 mm) particles.