The effects of trophic transfer and environmental factors on microplastic uptake by plaice, Pleuronectes plastessa, and spider crab, Maja squinado

Abstract

Microplastic pollution is apparent throughout the marine environment from deep ocean sediments to coastal habitats. Most of this is believed to originate on land, although marine activities, such as fishing and shipping, also contribute to the release and redistribution of microplastic. The relative importance of these maritime plastic sources, the manner by which they are distributed in the environment, and their effect on uptake by marine organisms are yet to be fully quantified. In this study, the relative impact of fishing activities on microplastic uptake by demersal fish and crustaceans was explored. Local fishing intensity, proximity to land and mean water velocity are compared to microplastic uptake in plaice, Pleuronectes platessa, and spider crab, Maja squinado, from the Celtic Sea. Observations were also made of microplastic contamination in ingested sand eels, Ammodytes tobianus, to establish a potential route of trophic transfer. This study is the first to identify microplastic contamination in spider crab and to document trophic transfer in the wild. Individuals were sampled from sites of varied fishing intensity in the Celtic Sea, and their stomach contents examined for the presence of microplastic. Contamination was observed in 50% of P. platessa, 42.4% of M. squinado, and 44.4% of A. tobianus. Locations of highest plastic abundance varied between P. platessa and M. squinado, indicating that different factors influence the uptake of microplastic in these two taxa. No significant link was observed between fishing effort and microplastic abundance; however, proximity to land was linked to increased abundance in M. squinado and Observations of whole prey demonstrate ongoing trophic transfer from A. tobianus to P. platessa. The lack of significant difference in microplastic abundance between predator and prey suggests that microplastic is not retained by P. platessa.

Natural history matters: Plastics in estuarine fish and sediments at the mouth of an urban watershed

“…These fish may, in turn, be important vectors for transferring small plastics and contaminants to the broader coastal food web given their abundance, their roles in connecting intertidal with both subtidal and terrestrial ecosystems, and their roles as forage fish for many species [92][93][94][95]. While examples of the transfer of plastics between trophic levels are on the rise [30][31][32][33], needed is a better understanding of the mechanisms underlying the pathways of…”

“…Furthermore, microplastics can sorb toxins such as metals, PCBs, PAHs, and DDT from the aquatic environment [23], and transmit these toxins to organisms [24], causing stress to internal organs, disruptions in normal bodily functions (e.g., enzyme inhibition, endocrine disruption), and reductions in organisms' abilities to defend themselves against predators and other threats [4,21,[25][26][27][28][29]. Microplastics have been found to transfer between trophic levels [30][31][32][33], and thus may pose health risks to humans via consumption of contaminated seafood (e.g., [34,35], though the impacts of microplastics on human health remain largely unknown [21,36].…”

Understanding How Microplastics Affect Marine Biota on the Cellular Level Is Important for Assessing Ecosystem Function: A Review

“…Observations of whole prey demonstrate trophic transfer from sand eels (Ammodytes tobianus) to plaice (Pleuronectes plastessa) in the wild. The lack of significant difference in microplastic abundance between predator and prey however suggests that microplastic is not retained by P. platessa (Welden et al 2018). The likelihood of secondary ingestion is limited, as retention times and transit of particles through the gut of a prey organism can be relatively fast.…”

Toward an Improved Understanding of the Ingestion and Trophic Transfer of Microplastic Particles: Critical Review and Implications for Future Research

“…Nevertheless, in the absence of tools applicable to assessment of the bioaccumulation of poorly soluble particulates, concerns regarding their ingestion and potential to bioaccumulate, particularly for microplastic particles, have recently been growing. For instance, both laboratory‐ and field‐based studies have aimed directly at assessing the extent and mechanisms related to the ingestion and trophic transfer of microplastic particles (Farrell and Nelson 2013; Santana et al 2017; Chae et al 2018; Chagnon et al 2018; Macali et al 2018; Nelms et al 2018; Welden et al 2018; Zhao et al 2018). These studies have demonstrated that organisms at lower trophic levels, such as macrozooplankton, are capable of ingesting microplastic particles either indirectly or directly as a consequence of mistaking the particles for food, and are then themselves ingested by organisms at higher trophic levels, suggesting a potential mechanism that might support arguments for the bioaccumulation and biomagnification of microplastic particles.…”