SREL Reprint #3816

Surface texture of macroplastic pollution in streams alters the physical structure and diversity of biofilm communities

Fabiola Lopez Avila1,2, Krista A. Capps1,2, and Raven L. Bier2

1Odum School of Ecology, University of Georgia, Athens, Georgia, USA
2Savannah River Ecology Laboratory, University of Georgia, Aiken, South Carolina, USA

Abstract: Biofilms can develop on nearly any surface, and in aquatic ecosystems they are essential components of biogeochemical cycles and food webs. Plastic waste in waterways is a new type of surface for biofilm colonisation. To analyse the influence of plastic pollution on the development and diversity of microbial freshwater biofilms that colonised them, we incubated 388 cm2 veneers of high-density polyethylene (HDPE) with two veneer textures, smooth and rough, and tulip tree wood (Liriodendron tulipifera), in three rural headwater streams at the Savannah River Site (Aiken, SC, USA). We collected biofilms from veneers after 14, 28 and 56 days of incubation and analysed 16S rRNA genes and biofilm properties. We found that plastic negatively affected species richness of biofilms compared with wood, but that evenness was greatest on rough textured HDPE. Beta diversity was primarily influenced by stream site. Beta diversity differed more between wood and plastic veneers than with plastic surface texture and became more different over time. Wood had nine times more biomass than rough HDPE and 40 times more biomass than smooth HDPE. Given the projected increase of macroplastic pollution in aquatic ecosystems, our findings emphasise the need to further understand its effects on biofilm characteristics.

Keywords: freshwater biofilms, macroplastic, microbial biofilms, plastic pollution

SREL Reprint #3816

Lopez Avila, F., K. A. Capps, and R. L. Bier. 2025. Surface texture of macroplastic pollution in streams alters the physical structure and diversity of biofilm communities. Environmental Microbiology Reports 17(e70068).

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).