Microplastics threaten Goa’s estuarine fisheries, human consumers

Microplastics Threaten Goa’s Estuarine Fisheries and Human Consumers

Context

A new study by the CSIR–National Institute of Oceanography (NIO), Goa, and the Academy of Scientific and Innovative Research, Ghaziabad, has revealed alarming levels of microplastic contamination in Goa’s coastal and estuarine ecosystems. The research identifies contamination in commercially important fish species and its potential risks to fish health, human consumers, and livelihoods.

Key Findings

• Samples Studied: 251 fish from nine species including mackerel, anchovy, sardine, catfish, oyster, clam, and bamboo shark.
• Microplastic Count: 4,871 particles detected; 3,369 identified as plastic polymers (19 types).
• Concentration:
  • Anchovies: 8.8 microplastic particles per individual (pelagic zone).
  • Catfish: 10 particles per individual (benthic zone).
  • Bamboo shark: 3.5 particles per individual.
• Habitat Findings:
  • Benthic zones (sea floor) showed higher contamination than pelagic waters.
  • Fish near contaminated sediments ingested more microplastics.
• Shapes Identified: Fibres (53%), Fragments (29.9%), Films (13.1%), Beads (4%).
• Colours Indicating Sources: Blue (37.6%), Black (24.3%), Red (12%), others—linked to fishing gear, e-waste, packaging, and textiles.

Biological & Human Impacts

• Fish Health: Altered gene expression, oxidative stress, reproductive damage, and stunted growth.
• Human Risks: Consumption of contaminated fish can cause immune dysfunction, brain toxicity, and elevated cancer risks.
• Nutritional Decline: 66 of 71 shellfish showed poor nutritional status due to microplastic ingestion.
• Socio-Economic Concern: Reduced market demand for contaminated fish could impact coastal livelihoods.

Scientific Concepts

• Bioaccumulation: Gradual buildup of microplastics within organisms at successive trophic levels.
• Trophic Transfer: Movement of microplastics up the food chain—from plankton to small fish, to larger predators, and ultimately to humans.

Policy and Environmental Implications

• Highlights the urgent need for regulation of fishing waste management and urban wastewater discharge.
• Reinforces the call for biodegradable materials and circular economy initiatives to limit plastic pollution.
• Suggests that even a “low-risk” categorization can have long-term ecosystemic consequences for estuarine biodiversity.

Relevance for UPSC

Paper: GS Paper III – Environment, Ecology & Biodiversity | GS Paper II – Governance

Themes:

• Marine Pollution and Waste Management
• Biodiversity Conservation
• Sustainable Fisheries and Livelihoods
• Environmental Governance and International Conventions (e.g., MARPOL, UNEP Plastic Treaty)

Analytical Insight

The findings underline how microplastic pollution has permeated every layer of marine ecology, threatening not only aquatic biodiversity but also human food security. Goa’s case reflects a larger global environmental governance challenge, emphasizing the urgency of integrating scientific monitoring, waste regulation, and public awareness in India’s coastal management strategies.

Updated - October 15, 2025 06:30 am | The Hindu