Abundance and characteristics of microplastics in gastrointestinal tracts and gills of croaker fish (Johnius dussumieri) from off Mumbai coastal waters of India.

The present study was conducted to establish the intensity of microplastic pollution in demersal fish species, Johnius dussumieri, from the north eastern coastal waters of the Arabian sea. MP recovered were analysed for size, morphology, colour, and polymer type. The study results indicated that the GI tract and gills of individual fishes had 6.6 ± 1.7 and 6.2 ± 1.7 items, respectively. The microplastics having a size of <100 µm consisting of beads were found to be most predominant. Black and blue were the most present colours of microplastic in the tissues. Among the different studied months, a higher number of MP incidence was observed in the post monsoon period. There is no significant correlation observed between the microplastic numbers in gills and guts tissue. The present study shows that there is a potential risk of microplastic bioaccumulation in the fish body and subsequent risk to the consumers and organisms sharing the food chain.

Baseline health risk assessment of trace metals in bivalve shellfish from commercial growing areas in the estuaries of Ashtamudi and Vembanad (Kerala, India).

Trace metal concentrations were monitored in the yellow clam (Paphia malabarica), green mussel (Perna viridis) and edible oyster (Crassostrea madrasensis) from growing areas in the Ashtamudi and Vembanad estuaries, Kerala. Samples of shellfish (clams n=26, mussels n=18, oysters n=36) and environmental parameters (salinity, temperature, pH and rainfall) were measured in these growing areas from July 2012 to December 2014. Ranges of mean annual concentrations (mg/kg) were Ni (0.46-0.65); Co (2.87-3.49); Fe (80.0-119.4); Mn (3.88-9.38); Zn (40.8-76.2); Pb (1.28-2.00); and Cu (1.59-4.38). In Ashtamudi, clams had higher mean concentrations of Ni, Co, Fe, Mn and Pb than oysters. Mean concentrations of Ni, Pb (in all species), Zn (in clams and mussels) and Cu (in mussels) did not exceed maximum permissible limits mandated by the Food Safety and Standards Authority of India. Mean Mn concentrations exceeded the World Health Organization guideline (1 mg/kg) in the three species while mean Fe concentrations in clams and oysters did not exceed the guideline (100 mg/kg). Target hazard quotients were generally ≤ 1, except for a few Pb results in clams and mussels. Although results suggest no health risk to consumers for the reference doses, daily intakes and elements considered, regular monitoring of trace metals is recommended to maintain consumer protection given increasing anthropogenic and climatic pressures on the shellfish growing areas.