A recent study published in the journal ‘Heliyon’ by the Wildlife Institute of India reveals that Gangetic dolphins are being exposed to harmful endocrine-disrupting chemicals (EDCs) through their diet. Researchers assessed the dietary risk from 39 EDCs present in fish species commonly consumed by these freshwater mammals.
The study found significant bioaccumulation of industrial chemicals like di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) in the dolphins’ prey. Additionally, traces of banned pesticides such as DDT and Lindane (γ-HCH) were detected, highlighting weak enforcement of environmental laws in the Ganga basin.
The Gangetic dolphin population has dropped by over 50 per cent since 1957, and their habitat range has decreased by nearly 25 per cent, despite their status as India’s national aquatic animal. With only five species of river dolphins remaining worldwide, the study warned that India could risk a repeat of the Yangtze River tragedy, where a similar species went extinct due to unchecked human activities.
The study identifies multiple sources of chemical contamination affecting Gangetic dolphins, including agricultural runoff, untreated effluents from the textile industry, vehicular emissions, inadequate solid waste management, and increasing tourism in ecologically sensitive zones.
Endocrine-disrupting chemicals (EDCs) are of particular concern due to their potential to interfere with hormone systems and reproductive health in mammals, while also remaining in ecosystems for extended periods, reported by PTI
Although standard toxicity risk assessments showed low threat levels, analysis using the more accurate reference dose method revealed that Gangetic dolphins face high exposure risks from seven major pollutants: DEHP, DnBP, DDT, arsenic, mercury, cadmium, and polychlorinated biphenyls (PCBs).
The researchers urged immediate inclusion of these substances in dolphin conservation and monitoring efforts. They also called for the creation of a scientifically robust national framework to evaluate and regulate chemical pollution in rivers.
Despite being listed under Schedule I of the Wildlife Protection Act, 1972, the study argues that legal protection must be backed by concrete policy action and stricter pollution control measures to ensure the survival of the species.
The research conducted from last year was one of the important documents that was published on a portal launched by the ministry of Jal Shakti to promote ecological data and conservation.
(With inputs from PTI)
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