Is Wild Marine Biota Affected by Microplastics?

Simple Summary Microplastics are ubiquitous particles with dimensions less than 5 mm. In the marine environment, due to their small size, they can be ingested by organisms. The purpose of this review is to describe the negative effects related to the ingestion of microplastics in wild marine organisms. At the moment, few effects caused by the ingestion of microplastics in wild marine organisms are known. The present review provides detailed information on the adverse effects of MPs on wild marine organisms, including tissue damage, fish condition, oxidative stress, immune toxicity, and genotoxicity. A bibliometric analysis was carried out on CiteSpace (version 6.1.R3) (Drexel University, Philadelphia, PA, USA) to verify how many papers studied the effects on wild marine species. The results showed a total of 395 articles, but only 22 really presented data on the effects or impacts on marine biota, and of these, only 12 articles highlighted negative effects. This review shows that the observed effects in wild organisms were less severe and milder than those found in the experimental conditions. The knowledge of negative effects caused by direct ingestion of microplastics in wild animals is still limited; more efforts are necessary to fully understand the role of MPs and the adverse effects on wild marine organisms, the ecosystem, and human health.