Microplastics pollution threatens Goa’s estuarine fisheries, human consumers, Pg2

Key Highlights:

• A study identified 4,871 polluting particles in 251 fishes of nine species off the Goan coast [mackerel, anchovy, oyster, clam, catfish, sardine].
• 3,369 particles were plastic polymers of 19 types, mainly from degraded fishing material and wastewater.
• Fish are suffering from disrupted gene expression, oxidative stress, reproductive damage, and lower growth.
• Human consumption of contaminated fish could lead to immune dysfunction, higher risk of cancer, and brain toxicity.

Detailed Insights:

• The study focused on the Mandovi estuarine system, which contributes to 97% of Goa’s fish output, using the bamboo shark as a focal species.
• Anchovies had the highest microplastic concentration among pelagic species (8.8 MP/in), while catfish led the benthic realm (over 10 MP/in).
• Fish with habitats closer to contaminated sediments ingested more microplastics, with the digestive tract being the primary ingestion pathway.
• The study categorized the region as low-risk but placed benthic life at more risk, noting that 11 of the 19 polymer types identified were highly toxic.
• Microplastics can indirectly affect coastal populations by lowering fish nutritional quality and threatening livelihoods due to decreased market demand.

Key Concepts Involved:

• Bioaccumulation: The accumulation of substances, such as microplastics, in an organism.
• Trophic transfer: The process by which microplastics move up the food chain.
• Estuaries: Ecologically critical zones that nourish young fish and serve as feeding grounds.