Abstract:
Plastic pollution causes serious ecological risks on biodiversity with toxicological effects
on the biota. The objective of this study was to assess microplastic accumulation in
seasonally common fishery resource: Stolephorus commersonnii (Commerson's Anchovy)
harvested from Madu-ganga estuarine ecosystem. Fifteen matured fish samples (n=15)
were randomly collected from local fishermen from November 2019 to January 2020.
Microplastic particles were extracted from the digestive tract and muscles of anchovies
using the recommended protocol of 10% KOH digestion. Hot needle test and Fourier
Transform Infrared Radiation (FTIR) analysis were used for the confirmation of
microscopically observed microplastics in anchovy samples. Microscopically observed
microplastics were counted and categorized according to the size, color, and shape of
plastics. Results revealed the microplastic accumulation in both the digestive tract and
muscles of anchovies. Microplastics accumulate into the muscles via translocation and
different respiratory modes. The average microplastic accumulation rate of anchovy gut
and muscles were recorded as 301.70±3.58 items/g and 29.33±1.19 items/g respectively.
White/transparent microplastic particles were the most abundant type in both guts
(145.50±2.18 items/g) and muscles (13.55±1.23 items/g) of fish. However, blue
(71.33+0.83 items/g: gut, 9.85+1.13 items/g: muscle), black (37.85+1.07 items/g: gut,
2.49+0.44 items/g: muscle), red (28.31+0.60 items/g: gut, 2.31+0.3 items/g: muscle) and
pink (15.31+0.34 items/g: gut 0.96+0.24 items/g: muscle) microplastic debris were also
recorded from gut and muscle samples. The majority of accumulated plastics in both gut
and muscles were at the size range of 0.50 -1.00 mm. Fiber shape microplastics were
observed in all the samples. FTIR results revealed that polypropylene as the only polymer
type of microplastics in fish muscles and gut. This polymer is a key component of fishing
ropes, netting materials, bottle caps, and packaging materials that enter through
tourism/recreational activities and fishery operations into the estuarine ecosystem.
Therefore, the current study recommends sustainable, integrated fishery management and
eco-tourism programs focusing on plastic pollution control and prevention activities in
Madu-ganga estuarine ecosystem. In conclusion, this study highlights the occurrence of
microplastic contamination in the estuarine biota and the urgent need for plastic wastes
management programs.
Keywords: Coastal fishery resources, Estuarine ecosystem, Integrated fishery
management, Microplastic accumulation rate, Plastic pollution control programmes
