Abstract:

Microplastic pollution is ubiquitous in lakes and rivers. Most studies look at contamination in the pelagic waters and animals. Exploring the interaction between macrophytes and plastic pollution represents a novel and emerging field of investigation. Moreover, researchers are trying to understand how shorelines are reservoirs for microplastics. The primary objective of this study is to examine the entrainment and accumulation of microplastic on shorelines, including in macrophytes and other relevant matrices. This research is part of the pELAstic project – a multiyear whole ecosystem experiment assessing the fate, transport, and effects of polyethylene (PE), polystyrene (PS) and polyethylene terephthalate (PET) microplastics in a remote boreal lake. In Summer 2023, we sampled microplastics from rock rings, the surface water surrounding macrophytes, and the macrophytes themselves along the littoral shoreline of L378 at the International Institute for Sustainable Development’s Experimental Lakes Area (IISD-ELA). Our investigation focuses on two distinct types of macrophytes, floating macrophytes and emergent macrophytes. In each matrix, we quantified and characterized microplastics in each matrix at six stations across the lake. There are relatively large amounts of microplastics on the shoreline, with more in locations that align with where the wind blows onto the shore. Moreover, the plastic that is visible on the shoreline is predominantly PE, a buoyant plastic. Within the macrophytes we are seeing large amounts of accumulation. By observing the amount accumulated at each station within each matrix we can understand the fate of microplastics on the littoral shoreline and how they may accumulate in each matrix. This study will contribute valuable insights into the dynamics of microplastic fate and their interaction with macrophytes and other littoral shoreline matrices in aquatic ecosystems.