The bivalve mollusk includes several economically important relevant for Chilean marine industry. Several of these species have aquaculture potential as Chilean clam (Venus antiqua) and Chorus mussel (Choromytilus chorus) or have been farmed, generating a relevant industry as Chilean mussel (Mytilus chilensis). However, these species remain in marine ecosystems, therefore, are exposed to different environmental stressors and pollutants. One of these pollutants are microplastics, which are abundant in marine environments. Due to its geographical location and biological characteristics, these species could be exposed to marine pollution, specially microplastics. This study aimed to evaluate the prevalence of microplastic in bivalve mollusks including Chilean clam (Venus antiqua), Chorus mussel (Choromytilus chorus) and Chilean mussel (Mytilus chilensis) from the coast of Chile.
These species of bivalve mollusks were sampled in central and south localities of the Chilean coast registering length, weight, and the tissue of the animals. The tissue was digested in KOH and then filtered using Whatman glass microfiber and analyzed using a high-resolution optical microscope. We found microplastic presence in the Chilean clam population of the central coast, with fiber as the most represented type of microplastic in this species. In the case of Chilean mussels, we also found the presence of microplastics in the sampled locations. Finally, in the Chorus mussel, the biggest species of the tree evaluated, we found important contamination with microplastic in the intestine (Fig 1A), while in gills, microplastic contamination was present but in a low level (Fig 1B), showing that exist a differential pattern of pollution according to tissue. Additionally, we observe that does not exist any direct correlation between the weight and length of the individual with microplastic contamination. This information is evidence that microplastic pollution level is a relevant issue for Chilean bivalve mollusks, and that could be influenced by species and location, requiring more studies to determine its effect at the physiological level on these species. Funding: Programa de Inserción Académica PIA 82510015.