Marine pollution from plastic waste is increasing all over the world, and it is expected that by 2050, the amount of plastic waste in the world's oceans will be higher than that of fish.In particular, "microplastics" with a particle size of 5 mm or less are taken up by all living things, so there are concerns about their impact on the marine ecosystem.
Marine animals not only take up microplastics directly from seawater, but also indirectly take them up by eating prey organisms that have microplastics in their bodies.We now find that in carnivorous fish, the indirect route through prey organisms takes up much more microplastics than the direct route from water.
In a group study of Hokkaido University, the carnivorous fish sculpin (hereinafter, sculpin) and its prey, Neomysis awats (hereinafter, mysidacea), were bred in a direct route from water and an indirect route via prey organisms. A comparison of microplastic intakes was made.As a result, the amount of microplastic ingested by sculpin by eating mysidacea was 3 to 11 times as much as the amount ingested from water.In addition, since the microplastic is atomized in the process of being taken up by the sculpin, the particle size of the microplastic taken into the sculpin by the indirect route is smaller than that taken by the direct route.
It has been pointed out that finely divided microplastics migrate from the digestive tract to internal tissues and have an adverse effect on the living body.Furthermore, since plastics contain toxic chemicals, there are concerns about the impact on higher consumers by concentrating them through the food chain.
In the future, it is hoped that the overall picture of the serious impact of microplastics on marine ecosystems through the food chain will be clarified.
Paper information:[Environmental Pollution] Trophy transfer of microplastics from mysids to fish greatly exceeds direct ingestion from the water column
