Plastic Additives in Two Macroinvertebrate Species of the Ganga River: A Case Study Across the Habitat of the Endangered Gangetic Dolphin

Plastic pollution presents a critical environmental challenge, with plastic waste infiltrating natural ecosystems and posing severe threats to biodiversity and human health. The issue is further amplified by the leaching of plastic additives (PAs) into rivers from inadequately managed terrestrial plastic waste. This study examines the occurrence and bioaccumulation potential of selected PAs in two freshwater macroinvertebrates inhabiting the habitat of the endangered Gangetic Dolphin, within a densely populated, agriculturally intensive, and tourism-driven landscape.
This study focuses on the Lamellidens marginalis (bivalve) and Filopaludina bengalensis (gastropod) to assess their suitability as biological monitors of PA contamination in an effluent-impacted stretch of the Ganga River. Samples were collected along a 25 km stretch of the Middle Ganga Reach, and seven PAs, including Dimethyl phthalate (DMP), Diethyl phthalate (DEP), Di-n-butyl phthalate (DnBP), Butyl benzyl phthalate (BBP), Bis(2-ethylhexyl) phthalate (DEHP), Di-n-octyl phthalate (DnOP), and Bisphenol A, were quantified using UHPLC–MS/MS and GC-MS-MS.
The bioaccumulation patterns observed in both the macroinvertebrate species were DnBP > DEHP > DEP > DMP > BPA, with BBP and DnOP concentrations observed below detection limits. L. marginalis showed particular promise for site-specific assessments due to its sedentary nature, limited mobility, ease of sampling, and longer lifespan, which are advantageous for reflecting localized contamination and understanding long-term trends. Using L. marginalis as biomonitors for PA contamination can provide critical insights into pollutant levels and sources in the Ganga River, enabling targeted remediation efforts, assessing habitat quality, identifying pollution hotspots, and informing conservation strategies.
This study is the first to investigate PAs in wild macroinvertebrates of the Ganga River, providing critical insights that can inform targeted remediation efforts and support conservation strategies for the endangered Gangetic Dolphin by improving habitat quality and reducing pollutant exposure.