Distribution of microplastics in Lusi Island, Sidoarjo, Indonesia

Abstract Lusi Island, situated downstream of the Brantas River, is anticipated to harbour significant microplastics from Brantas River runoff. Consequently, a thorough analysis of the microplastic presence on Lusi Island is crucial for effective pollution mitigation. Despite the critical need for such investigations, more studies must report the abundance of microplastics in this locale. This study aims to fill this gap by examining the abundance of microplastics in the downstream area of the Brantas River, specifically Lusi Island. The research not only delves into the prevalence of microplastics but also investigates various water quality parameters, including dissolved oxygen, pH, temperature, turbidity, and total dissolved oxygen. The study reveals that the abundance of microplastics in Lusi Island ranges from 597 to 787 particles per litre in surface water samples. Three distinct types of microplastics—fragments, fibres, and film—were identified on the island. Notably, microplastic fragments dominate in number compared to other forms. Despite the favourable water quality parameters suggesting a healthy aquatic environment, the study underscores the necessity of implementing mitigation measures to address microplastic pollution effectively.