Abstract

GOMEZ, Jonatan et al. First experimental approach to the accumulation and deposition of microplastics in lichen. Rev. Int. Contam. Ambient [online]. 2023, vol.39, 54843.  Epub Feb 12, 2024. ISSN 0188-4999.  https://doi.org/10.20937/rica.54843.

One of the most important problems related to plastic waste is the production of microplastics (MPs), whose accumulation in different taxa has been recorded. It was recently found through field sampling that lichens are able to accumulate MPs. The present work aims to experimentally study the accumulation and deposition of MPs in three lichen species of the genera Usnea, Ramalina and Punctelia. We measured the weight, water uptake and fractal dimension of each thallus. Under laboratory conditions, we exposed 12 thalli of each species to three different doses of MPs in aqueous suspension (3, 6, and ≤12 MP/mL) for one week. The accumulated and deposited MPs were extracted and counted. Accumulation was negligible. We modelled deposition with general linear models. The fractal dimension variable was the only one significantly related to deposited MPs. These results suggest that in communities with higher structural complexity, measured by fractal dimension, we will find higher levels of deposited MPs.

Keywords : lichenized fungi; plastics; microspheres; bioaccumulation; pollution.