Evaluation of microplastics in marine selective and non-selective suspension-feeding benthic invertebrates

Microplastic (MP) pollution is ubiquitous in marine ecosystems, presenting significant concerns to organisms and fisheries. Suspension-feeding invertebrates are particularly susceptible to encountering and consuming these particles due to their feeding strategy. This meta-analysis assessed MP contamination in selective suspension-feeding (SSF) and non-selective suspension-feeding (NSSF) benthic marine invertebrate species globally. Data reported from 144 peer-reviewed articles, covering as wide of a geographic scope as possible, were extracted and analyzed. In total, 518 independent batches of organisms (i.e. rows in the spreadsheet) were compiled, representing seven Phyla, 12 Classes, 53 Families, and 131 species. In both SSFs and NSSFs, microfibers and fragments were the most common MP shapes found, with polyethylene, polyethylene terephthalate, and polypropylene being the predominant polymer types. While the mean detection frequencies of MPs within individuals of each independent sample batch were similar between SSFs (63 % ± 18 95 %CI) and NSSFs (73 % ± 5 95 %CI), NSSFs had significantly greater MP concentrations than SSFs (i.e. 9.13 MPs ind-1 ±8.87 95 %CI; 138.52.74 MP g ww^-1 ±114.6 95 %CI vs. 6.33 MPs ind-1 ±1.53 95 %CI; 3.45 MP g ww^-1 ±1.19 95 %CI, respectively). Significant differences in the relative abundance of MPs were also found based on taxonomy. Collectively, these results highlight important differences in MP concentrations in suspension-feeding benthic invertebrates globally and may help inform future efforts in determining appropriate sentinel species for future MP surveys.