Microplastic contamination of the drilling bivalve Hiatella arctica in Arctic rhodolith beds

Sebastian Teichert,Christian Schulbert,Marlene Mordek,Max Wisshak,Martin G J Löder,Ines Pyko,Christian Laforsch

doi:10.1038/s41598-021-93668-w

Sebastian Teichert, Christian Schulbert + Show 5 more

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https://doi.org/10.1038/s41598-021-93668-w

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Abstract

There is an increasing number of studies reporting microplastic (MP) contamination in the Arctic environment. We analysed MP abundance in samples from a marine Arctic ecosystem that has not been investigated in this context and that features a high biodiversity: hollow rhodoliths gouged by the bivalve Hiatella arctica. This bivalve is a filter feeder that potentially accumulates MPs and may therefore reflect MP contamination of the rhodolith ecosystem at northern Svalbard. Our analyses revealed that 100% of the examined specimens were contaminated with MP, ranging between one and 184 MP particles per bivalve in samples from two water depths. Polymer composition and abundance differed strongly between both water depths: samples from 40 m water depth showed a generally higher concentration of MPs and were clearly dominated by polystyrene, samples from 27 m water depth were more balanced in composition, mainly consisting of polyethylene, polyethylene terephthalate, and polypropylene. Long-term consequences of MP contamination in the investigated bivalve species and for the rhodolith bed ecosystem are yet unclear. However, the uptake of MPs may potentially impact H. arctica and consequently its functioning as ecosystem engineers in Arctic rhodolith beds.

Highlights

There is an increasing number of studies reporting microplastic (MP) contamination in the Arctic environment
Following the criteria developed by the US National Oceanic and Atmospheric Administration (NOAA), MPs refer to plastic items smaller than 5 m m10 and comprise a very heterogeneous group of particles that vary in polymer composition, additive content, size, shape, colour, origin, ageing state, and their physicochemical properties[11]
In the Arctic, rhodolith beds are especially prominent around the Svalbard archipelago[37,38], where they are built by coralline red algae mainly of the species Lithothamnion glaciale Kjellman, 1883. Many of those beds are dominated by hollow rhodoliths, which are generated by boring bivalves of the species Hiatella arctica (Linnaeus, 1767) that drill burrows into the rhodoliths which serves as protection against predators[39]

Summary

Introduction

There is an increasing number of studies reporting microplastic (MP) contamination in the Arctic environment. We analysed MP abundance in samples from a marine Arctic ecosystem that has not been investigated in this context and that features a high biodiversity: hollow rhodoliths gouged by the bivalve Hiatella arctica. This bivalve is a filter feeder that potentially accumulates MPs and may reflect MP contamination of the rhodolith ecosystem at northern Svalbard. Kamenos et al.[44] stated that due to the richness of food, rhodolith beds probably have a high holding capacity for juvenile gadoids, and are an important part of the inshore nursery system for commercial gadoid species like cod (Gadus morhua), saithe [Pollachius virens (Linnaeus, 1758)], and pollack [Pollachius pollachius (Linnaeus, 1758)] This renders the rhodolith beds potentially economically significant. Negative effects evoked by anthropogenic stressors on the bivalve-modified rhodolith microhabitat would imply negative consequences for a wide range of associated species

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