Seasonal ice encapsulation: the pivotal influence on microplastic transport and fate in cold regions

Owing to their small size and stability, MPs have been found to be present in different media all over the world, even in the most remote regions such as the Arctic and Antarctic. The presence of MPs in the waters of the Arctic and Antarctic regions has been widely documented for decades, but the phenomenon of MPs becoming concentrated in sea ice was first reported only ten years ago. The successive reduction in the Arctic sea ice extent during the summer months in recent years could lead to a significant release of MPs that have accumulated over the past decades, potentially yielding unforeseen impacts on the ecosystems of cold regions. However, there has been limited research on the mechanisms and physical processes that govern the incorporation of MPs into the growing ice matrix. The incorporation of MPs during the ice formation process is influenced by polymer properties and prevailing environmental conditions. Therefore, it is becoming increasingly important to investigate the effects of freezing on MP behavior in aquatic environments, especially considering the potential release of accumulated MPs as sea ice continues to diminish.