MICROPLASTIC POLLUTION IN FISH FROM THE XIANGJIANG RIVER BASIN

In order to investigate microplastic contamination in fish from the Xiangjiang River basin in Hunan Province, the digestive tracts and gills of 128 fish from 13 sampling sites in the mainstem and tributaries of the river were collected. The results showed that 646 microplastics were detected in 120 fish, with a detection rate of 93.52% and an average abundance of (5.05±2.29) terms/tail, rangeing from 0 to 17 terms/tail. Microplastics were not detected in only 8 fish, distributed in two sampling points CL and WC. Meanwhile, the highest average abundance of microplastics was found at site GY (8.13±3.24 per/tail) and the lowest at site YX (3.06±0.67 per/tail). Microplastics abundance in the gills (2.79±1.59) terms/tail was higher than that in the digestive tracts (2.26±0.96) terms/tail. Among the detected microplastics, the highest percentage of particle size ≤2 mm (73.84%), and more than 67% were blue or black, predominantly fibrous (64.70%). The proportion of fibrous microplastics in the gills (72.43%) was significantly higher than that in the digestive tract (59.67%, P<0.05). Among the collected fish, the highest abundance of microplastics was found in Hemiculter leucisculus (8.42±4.22 per/tail), which was significantly higher than that of Culter alburnus (4.40±2.48 per/tail). In addition, benthic fish had higher microplastic content than pelagic fish. Fourier transform infrared analysis identified nine different polymer types, with polyethylene (PE) and polypropylene (PP) being the most common, accounting for 45.00% and 18.75%, respectively. This study reports on the microplastic contamination and characteristics in fish from the Xiangjiang River basin, providing essential data for the management and control of microplastic pollution in Xiangjiang River basin.