The increasing use of biodegradable plastics, derived from both fossil and renewable resources, raises questions about their actual degradation and ecological interactions in aquatic environments. While these materials are designed to be more environmentally friendly, their persistence and the biological communities they host under natural conditions remain poorly understood.

In this study, we investigated the long-term behavior of biodegradable plastic films incubated for over a year in the surface waters and sediments of Lake Maggiore (Northern Italy). We focused on changes in the physical and chemical properties of the materials, as well as the structure of microbial and diatom communities colonizing their surfaces.

Preliminary results suggest measurable degradation of the films over time, evidenced by alterations in spectral and thermal properties, changes in shape and weight, and visible fragmentation. Differences were observed between materials derived from renewable versus fossil sources, with some showing greater structural changes than others.

These findings highlight the complex interactions between biodegradable plastics and freshwater ecosystems, emphasizing the need to evaluate their performance and ecological footprint under realistic environmental conditions. Further analyses are ongoing to characterize the biofilm communities in greater detail and quantify degradation rates.