Size selection in sampling nets leads to underestimation of microplastic pollution.

Microplastic (MP) contamination in marine environments is a growing concern; however, the selectivity of sampling nets can introduce significant biases in MP pollution monitoring and assessments, particularly for smaller MPs, leading to an underestimation of their presence and complicating data comparability across studies. This study addresses this challenge by developing a new selectivity model that accounts for the biases in assessments. Further, it provides a robust framework for correcting MP concentration data.