Sal and Terekhol estuaries polluted with microplastic, poses risks: Study

SHWETA KAMAT MAHATME | JANUARY 29, 2025, 01:08 AM IST

PANAJI
Increasing human activities like fishing, discharge of raw sewage and disposal of plastic waste has turned Sal and Terekhol river estuaries highly contaminated with microplastic (MP) thus posing possible human and ecological risk. A study by Goa University, underscores a need for immediate attention to this environmental issue.

A comprehensive study of MP under “Comparative assessment of microplastic pollution in Terekhol and Sal estuaries, Goa, India” by Niyati Kalangutkar, Shritesh Mhapsekar and Parvathy Rajagopal, reveals concerning levels of MP abundance in both the estuaries.

“Overall, while both estuaries face challenges related to MP pollution, the situation in Sal estuary is exacerbated by more significant anthropogenic pressures, such as the presence of the fishing jetty, untreated sewage discharge, and contaminated tributaries, leading to its slightly higher prevalence of MPs. The Terekhol estuary, although not immune to these issues, appears to be less severely impacted, with its MP sources being somewhat less intense or widespread,” the study stated.

According to the Varsity, both estuaries are characterised by a predominance of MPs within the 5–1 mm size range, with white MPs being the most prevalent in colour. The MPs study revealed that both estuaries are polluted with MPs at all studied locations. The abundance of MPs in Terekhol estuary ranged from 0.01 to 0.85 particles/L, with an average of 0.25 particles/L, whereas in Sal estuary it ranged from 0.01 to 0.59 particles/L, with an average of 0.30 particles/L.

While fibres are more prevalent in Terekhol, whereas Sal estuary is dominated by fragmented MPs. Polyethylene (PE), polypropylene (PP), and polyamide (PA) are the dominant polymers in both Terekhol and Sal estuaries, with polyolefins (PE and PP) highlighting the extensive use and environmental impact of these plastics.

“Key sources of MPs in these estuarine systems appear to include human activities such as fishing (e.g., fishing nets), everyday plastic products, sewage discharge, packaging, and ropes,” it said adding that the findings suggest that river inflows and fishing-related activities are likely the primary contributors to pollution caused by MPs in these estuaries.

The researchers have recommended that for effective management of MP pollution, it is critical to build a system for continuous monitoring of MP in these estuaries in order to better understand pollution sources.

“Policy interventions focused on reducing single-use plastics, improving waste management systems, and enhancing public awareness are crucial to mitigating MP inputs in these coastal ecosystems. Additionally, future research should include comprehensive eco-toxicological assessments to evaluate the potential impact of MP-bound metals and polymers on local aquatic fauna,” they said.

According to them, the goal of reducing MP pollution and protecting the ecological integrity of Goa’s estuarine environments can be achieved more effectively through a combined approach of regulatory actions and research initiatives.

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