Occurrence of Microplastics in the Gastrointestinal Tract and Gills of Fish from Guangdong, South China

Abstract

Microplastic pollution has become a major global concern. Coastal areas are densely populated with human activity, commercial enterprises, and fishing, resulting in high incidences of fish microplastic pollution. It has been shown that microplastics exist in commercial fish in coastal areas of Guangdong, China. Most of the microplastics were less than 1 mm, white and blue fibers. The abundance, type, shape and color of microplastics in gills and in the gastrointestinal tract (GIT) of eight species of commercial fish in the coastal waters of central and western Guangdong Province were analyzed. The overall abundance of microplastic particles in fish was 6.6 items/individual, with an average of 2.2 particles in gills and 4.4 in the GIT. The GIT of carnivorous fish was less likely to ingest microplastics than that of herbivores or omnivores. Middle-water fish, on the other hand, are less likely to have their gills contaminated with microplastics. These results revealed the degree of microplastic pollution in fish tissues from the central and western coastal areas of Guangdong province. The quantity of microplastics in the GIT of fish in the Pearl River Delta was the highest compared with the surrounding areas.

Microplastics found in the World Heritage Site Cocos Island National Park, Costa Rica

“…The majority (63%) of the MPs found in organisms were classified as microfibers, this result is consistent with those of Celik (2021), Makhdoumi et al (2021) andPan et al (2021). According to the literature, microfibers are considered as the major marine pollutant throughout the world.…”

Microplastic prevalence in marine fish from onshore Beibu Gulf, South China Sea

“…Zhang et al (2021) KK found that the microplastic abundance in fish from the mangrove wetland of Beibu Gulf was 0.72-5.39 items per individual, and the count was also high in GITs than in gills. Of the 80 fish studied, only three had no microplastics, and the average quantity was 6.6 items per individual in fish bodies from central and western coastal areas of Guangdong Province (Pan et al, 2021). Moreover, the average abundance of 584 fish individuals was 2.14 items per individual from Bohai Sea, China (Wang et al, 2021).…”

Characteristics of Microplastic in Commercial Aquatic Organisms

“…The morphology, color, and size of the microplastics present in the body of the biota vary with different point sources and non-point sources of microplastics as a result of human activities. Most of the studies have demonstrated that microplastics within biota are commonly found in the gastrointestinal tract and guts of fish and crustaceans and in the tissues of bivalve species [56][57][58][59]. The accumulation of microplastics can have an ecotoxicological impact on these living organisms, affecting their growth and reproduction [60][61].…”

“…A lower concentration of microplastics is discovered in herbivorous fish, which is around 3.56 microplastics per 100 grams compared to carnivorous, omnivorous, and insectivorous fish due to their accidental or indirect consumption of microplastics [33]. However, because herbivorous fish consume more food and have a higher tendency for microplastic accumulation in the gastrointestinal tract from plants, microplastic accumulation in herbivorous fish is much higher than in carnivorous fish [57].…”

“…The study by Pan et al also showed that there is a higher abundance of microplastics in the gastrointestinal tract of fish compared to the gills, where 351 and 177 microplastics are found in the GI tract and gills, respectively. Pan et al observed the dominance of fibrous microplastic particles smaller than 1 mm in fish gills, which is associated with the gill structure similar to a comb, allowing for more fiber retention at their gills [57].…”