Liang, Tanner
Abundance and Distribution of Microplastics in Lake Scugog Catchment, Ontario
Plastic pollution is a growing concern, owing to its durability, ubiquity, and potential health impacts. The overall objective of this study was to assess the abundance and distribution of microplastics within Lake Scugog catchment, Ontario. This was fulfilled through two tasks (i) the development of a microplastic particle budget for the lake catchment, and (ii) the determination of the dry deposition of atmospheric microplastics in Port Perry, Ontario. The total input of microplastics into Lake Scugog (atmospheric deposition and stream inflow) was 2491 x106 mp/day, while the output (lake outflow and sedimentation) was 1761 x106 mp/day, suggesting that 29% of inputs were retained in the lake. The dry deposition of microplastics in Port Perry was 1257 mp/m2/day, which was high when compared to bulk deposition (37 mp/m2/day) in the same area. By quantifying the major pathways of microplastics better management techniques can be implemented.
Author Keywords: Catchment, Dry Deposition, Microplastics, Ontario, Particle Budget, Plastic pollution
Hydrochemistry and critical loads of acidity for lakes and ponds in the Canadian Arctic
Threats such as climate change and increased anthropogenic activity such as shipping, are expected to negatively affect the Arctic. Lack of data on Arctic systems restricts our current understanding of these sensitive systems and limits our ability to predict future impacts. Lakes and ponds are a major feature of the Arctic landscape and are recognized as 'sentinels of change', as they integrate processes at a landscape scale. A total of 1300 aquatic sites were assessed for common chemical and physical characteristics. Geology type was found to be the greatest driver of water chemistry for Arctic lakes and ponds. Acid-sensitivity was assessed using the Steady State Water Chemistry model and a subset of 1138 sites from across the Canadian Arctic. A large portion of sites (40.0%, n = 455) were classified as highly sensitive to acidic deposition, which resulted in a median value of 35.8 meq·m―2·yr―1 for the Canadian Arctic. Under modelled sulphur deposition scenarios for the year 2010, exceedances associated with shipping is 12.5% (n = 142) and 12.0% (n = 136) for without shipping, suggesting that impacts of shipping are relatively small.
Author Keywords: Acidic deposition, Arctic lakes, Critical loads, Shipping emissions, Steady-State Water Chemistry Model, Water chemistry