Why in News ?
- A recent scientific study reported microplastics in all 20 sampled sites in Bhitarkanika National Park, with concentrations up to 50.4 items/kg sediment, signalling pollution ingress even into protected mangrove ecosystems.
Issue in Brief
- India’s second-largest mangrove ecosystem is emerging as a sink for microplastics, with 89% fibre-based particles, raising concerns of toxic accumulation, biodiversity loss, and food-chain contamination.
Relevance
- GS Paper III (Environment)
- Pollution; microplastics; coastal ecosystem degradation
- Importance of wetlands → Bhitarkanika National Park
Practice Question
Q. “Microplastic pollution represents an emerging threat to marine and coastal ecosystems.” Examine its sources, impacts, and policy responses in India. (250 words)
Static Background & Basics
Bhitarkanika Ecosystem (River–Mangrove System)
- Located in Kendrapara district, Odisha, Bhitarkanika is formed by a deltaic network of rivers—Brahmani, Baitarani, Dhamra, and their distributaries, draining into the Bay of Bengal, creating a rich estuarine-mangrove interface.
- It hosts India’s second-largest mangrove forest, after Sundarbans, and is a Ramsar site (wetland of international importance), supporting saltwater crocodiles, migratory birds, and Olive Ridley turtles.
- Mangrove roots act as natural sediment traps and bio-shields, protecting coasts from cyclones, but also function as pollution sinks, accumulating contaminants carried by upstream rivers.
Microplastics: Conceptual Basics
- Microplastics (<5 mm) originate from degradation of plastic waste or synthetic fibres (textiles, fishing nets), entering water systems via runoff, sewage, and riverine transport.
- They are non-biodegradable, persist for decades, and can adsorb heavy metals and toxins, making them more hazardous than bulk plastics.
Overview
- Detection across 100% sampling sites indicates basin-wide pollution, confirming that protected areas like Bhitarkanika are ecologically linked to upstream activities in the Brahmani river basin.
- Dominance of polyamide fibres (89%) points to sources such as synthetic textiles and fishing gear, highlighting urban wastewater and coastal livelihood activities as key drivers.
- Presence of heavy metals (lead, arsenic, cadmium, zinc) attached to microplastics converts them into toxic carriers, significantly increasing ecological and human health risks.
- Mangroves’ filtering function creates a paradox: while they trap pollutants and protect coastlines, they become long-term accumulation zones, intensifying exposure for benthic organisms.
- Bioaccumulation pathway: microplastics ingested by plankton and small marine organisms move up the food chain, affecting fish, birds, and ultimately human consumers.
- Despite moderate particle density compared to urban coasts, risk indices show “high–extreme” ecological risk, indicating that chemical composition (polyamide hazard) matters more than quantity.
- Highlights a classic externality problem, where upstream industrial, agricultural, and urban activities impose environmental costs on downstream ecosystems.
Challenges
- Absence of explicit microplastic standards under environmental laws (EPA, Water Act).
- Weak sewage treatment systems, especially lacking filtration for microfibres.
- Fragmented river basin governance, limiting coordinated pollution control.
- Lack of periodic national monitoring framework for microplastics.
Way Forward
- Adopt river-basin management approach for Brahmani–Baitarani system to control upstream pollution sources.
- Upgrade wastewater treatment plants with microfibre filtration technologies.
- Include microplastics in Environmental Impact Assessment (EIA) norms.
- Promote plastic circular economy: recycling fishing gear, textile innovation, waste reduction.
- Institutionalise regular monitoring (every 1–2 years) through CPCB, SPCBs, and research bodies.
Prelims Pointers
- Bhitarkanika is a Ramsar wetland with mangrove ecosystem.
- Microplastics act as vectors for heavy metals and persistent pollutants.
- Mangroves provide coastal protection, carbon sequestration (blue carbon).
Mains Enrichment
Intro Options
- “The spread of microplastics into protected ecosystems underscores the interconnected nature of environmental degradation.”
- “Mangrove ecosystems, though resilient, are increasingly becoming sinks of anthropogenic pollution.”
Conclusion Frameworks
- “Sustainable conservation requires shifting from site-based protection to basin-level governance.”
- “Preventing pollution at source is more effective than restoring degraded ecosystems, aligning with the precautionary principle.”
