Analysis of microplastics in the estuary lying along the coastal belt of the Arabian Sea

Abstract

The significant impact of microplastics in the marine environment has sparked global concern. These tiny plastic particles travel from land to the estuary through rivers, where they become intricately distributed within the estuarine dynamics. The spatial distribution of plastic debris and sedimentation in the estuary is mainly influenced by the dynamics of the estuary, posing a scientific challenge that demands immediate attention. The main objective of this study is to analyse the microplastic contamination in the water samples collected from the Azhikkal estuary in Kannur, India, subsequent to the establishment of a seaport in the region, using a home assembled micro-Raman spectrometer. This research sheds light on the extensive prevalence of microplastics detected in the vicinity of the estuary’s entrance, with a specific focus on the consequences of seaport construction in the surrounding region. Within the surveyed region, a considerable quantity of 1260 microplastic particles and 1480 anthropogenic particles were identified. The predominant plastic varieties observed in this particular area consist of polystyrene (38 %), polysulfone (5 %), polypropylene (1 %), and polyethylene terephthalate (1 %). The predominant microplastics discovered in this region consisted mainly of fragments (82 %) and fibers (15 %), varying in sizes from 10 to 100 μm (36 %), resulting in a higher surface area to volume ratio. The existence of red and blue pigments, such as copper phthalocyanine and indigo blue, in plastic pollution discovered in this vicinity is causing alarm over the potential harmful consequences on marine organisms that rely on these ecosystems. The identification of these pigments in the estuarine region and aquatic environments across the entire nation has not been adequately pursued. Additionally, this research delves into the spread of microplastics in the murky estuarine setting, considering the significant impact of sea surface wind and alterations in buoyancy following the formation of a biofilm on their surface. This leads to the microplastics acquiring hydrophilic characteristics within the turbid estuarine environment.