Microplastic ecology: Testing the influence of ecological traits and urbanization in microplastic ingestion by sandy beach fauna

Sandy beaches are sources and sinks of plastics, and multiple species with different individual traits coexist. Thus, this ecosystem can be considered ideal model for comparative studies on MP ingestion by organisms from different ecological guilds. We aimed to investigate whether the suspected microplastic (SMP) concentration and richness (number of SMP morphotypes and colors) in beach macroinvertebrates and fishes vary according to urbanization, feeding modes and habitat. Among macroinvertebrates, the highest abundance of SMP was found in deposit-feeder species, in the supralittoral zone, and in high-urbanized beaches. However, the highest SMP richness was observed in carnivorous species from surf zones. Among fish, the highest abundance of SMP was found in pelagic planktivores. The proportion of SMP morphotypes varied significantly between abiotic and biotic compartments, suggesting selectivity in particle ingestion or excretion. Our results support the use of deposit-feeder macroinvertebrates from the supralittoral as indicator of MP pollution in sandy beaches.

Automated summary

Sandy beaches are ideal models for comparative studies on MP ingestion because they are both sources and sinks of plastics, while accommodating multiple species with different traits. The concentration and richness of suspected microplastics (SMP) in beach macroinvertebrates and fishes vary according to urbanization, feeding modes, and habitat. Our results suggest that deposit-feeder macroinvertebrates from the supralittoral can be used as indicators of microplastic pollution in sandy beaches.