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Experimental Evaluation of Seaweeds as a Vector for Microplastics into Marine Food Webs
journal contribution
posted on 2016-01-19, 00:00 authored by Lars Gutow, Antonia Eckerlebe, Luis Giménez, Reinhard SaborowskiThe ingestion of microplastics has
been shown for a great variety
of marine organisms. However, benthic marine mesoherbivores such as the common periwinkle Littorina littorea have been largely disregarded
in studies about the effects of microplastics on the marine biota,
probably because the pathway for microplastics to this functional
group of organisms was not obvious. In laboratory experiments we showed
that the seaweed Fucus vesiculosus retains
suspended microplastics on its surface. The numbers of microplastics
that adhered to the algae correlated with the concentrations of suspended
particles in the water. In choice feeding assays L.
littorea did not distinguish between algae with adherent
microplastics and clean algae without microplastics, indicating that
the snails do not recognize solid nonfood particles in the submillimeter
size range as deleterious. In periwinkles that were feeding on contaminated
algae, microplastics were found in the stomach and in the gut. However,
no microplastics were found in the midgut gland, which is the principle
digestive organ of gastropods. Microplastics in the fecal pellets
of the periwinkles indicate that the particles do not accumulate rapidly
inside the animals but are mostly released with the feces. Our results
provide the first evidence that seaweeds may represent an efficient
pathway for microplastics from the water to marine benthic herbivores.