Composition and relative abundance of plastic debris along Manora and Sandspit beaches, Karachi, Pakistan

Abstract

The surge in plastic debris poses a critical global concern, driven by escalated consumption, accumulation, and enduring persistence in the environment. This study sought to evaluate the composition and relative abundance of plastic debris on Manora and Sandpit beaches in Karachi, Pakistan. Employing 24 transects, each with a fixed length of 100 m and a variable width of 25 m (corresponding to beach width at the sampling site) during the lowest tides, the sampling sites were determined using GPS coordinates. Plastics exceeding 2.5 cm were meticulously collected, then subjected to thorough cleansing, washing, and drying processes. Subsequently, adhering to the OSPAR Guideline for Monitoring Marine Litter on Beaches (2010), the plastics were sorted, enumerated, and categorized into ten predetermined waste categories. The designated transects carried 57.5 ± 44.17 plastic items 100 m^-1 and weighed 568.37 ± 432.76 g 100 m^-1. Notably, branded plastic items predominated in terms of quantity, typically falling within the size range of 2.5 to 10 cm. The primary source of plastic pollution at these beaches stems from land-based littering, notably from local communities and beach visitors engaged in recreational activities. Contrary to the trend observed in heavily frequented global beaches, the present study unveils relatively low plastic debris on the designated Karachi beaches To safeguard Pakistan’s coastal and marine resources, the study advocates for the adoption of effective waste management practices in the area.