Overview of global status of plastic presence in marine vertebrates

Abstract

The presence of plastic in the environment is generating impacts on all habitats and has become a major global problem in marine megafauna. Macroplastics can cause entanglement, ingestion and loss of suitable habitats. In addition to entanglement problems, there is evidence that plastics are entering the food web through ingestion by marine organisms, which could ultimately be affecting humans. Much of the available information on the impact of plastic in biota is scattered and disconnected due to the use of different methodologies. Here, we review the variety of approaches and protocols followed to assess macro‐ and microplastic ingestion in marine vertebrates such as sea turtles, cetaceans and fishes in order to offer a global overview of their current status. The analysis of 112 studies indicates the highest plastic ingestion in organisms collected in the Mediterranean and Northeast Indian Ocean with significant differences among plastic types ingested by different groups of animals, including differences in colour and the type of prevalent polymers. In sea turtles, the most prevalent types of plastics are white plastics (66.60%), fibres (54.54%) and LDPE polymer (39.09%); in cetaceans, white macro‐ and microplastics (38.31%), fibres (79.95%) and PA polymer (49.60%); and in fishes, transparent plastics (45.97%), fibres (66.71%) and polyester polymer (36.20%). Overall, clear fibre microplastics are likely the most predominant types ingested by marine megafauna around the globe.

Microplastics and anthropogenic fibre concentrations in lakes reflect surrounding land use

“…First, the small size and wide distribution of microparticles-often defined in surface waters as particles between 300 μm and 5 mm [3]-makes them easily ingested by microscopic to large animals, posing distinct toxic hazards [4][5][6]. Fibre microparticles are, for example, the most common size class of anthropogenic debris reported to be ingested by marine vertebrates [7]. Microparticles can also support denser biofilm colonies than larger debris and become aggregated with microbial cells [8].…”

Impact of Plastic Debris on the Gut Microbiota of Caretta caretta From Northwestern Adriatic Sea

“…The present study explored the plastic debris (PD) amount in the feces of wild captured loggerhead sea turtles (C. caretta), dwelling in the Northwestern Adriatic Sea, collected after their arrival at a local rescue center for their rehabilitation. Large marine vertebrates, such as cetaceans and sea turtles, are ideal sentinels to monitor plastic pollution in marine environment but, thus far, data on the impact of plastic ingestion on such wild species have been necessarily provided mostly through sampling of gastrointestinal contents from dead animals (López-Martínez et al, 2020). By employing fecal samples, our approach attempts to assess the actual distribution of PD in the gastrointestinal tract of live animals at different life stages, although it is challenging to compare our results with the available literature.…”

“…Once plastics are ingested by sea turtles, either actively (i.e., by mistaking plastic residues for pray), indirectly (feeding on animals which previously ingested plastics), or accidentally (Schuyler et al, 2016;Nelms et al, 2018), they mainly accumulate within the gastrointestinal tract, due to the inability of the animal to regurgitate items (Matiddi et al, 2017;Wilcox et al, 2018;Santos et al, 2020). Several studies have already investigated the presence of plastic pollution in different species of sea turtles, but the vast majority of them were performed on gastric contents taken from dead animals (Caron et al, 2018;Duncan et al, 2019;Digka et al, 2020;López-Martínez et al, 2020). Besides leaving a considerable gap of knowledge in monitoring the actual plastic contamination of live animals, it has been pointed out that the sole observation of the upper part of the intestinal tract, taken during necroscopy, can underestimate the real magnitude of plastic ingestion by the animal (Bjorndal et al, 1994;Pham et al, 2017).…”

Seafood Processing, Preservation, and Analytical Techniques in the Age of Industry 4.0

“…Microplastics in marine ecosystems are those small plastic fragments that can be consumed by aquatic species (e.g., fish, shellfish, marine invertebrates) and transferred along the food chain to human beings [112][113][114][115]. To detect and identify microplastics, several approaches have been developed, ranging from the simple visual inspection to more advanced techniques, such as chromatography coupled with mass spectrometry and spectroscopic techniques [114,[116][117][118][119].…”