Bioavailability of Microplastics to Marine Zooplankton: Effect of Shape and Infochemicals.

Zara L R Botterell,Frances E Hopkins,Michael Steinke,Richard C Thompson,Nicola Beaumont,Penelope K Lindeque,Matthew Cole

doi:10.1021/acs.est.0c02715

Zara L R Botterell, Frances E Hopkins + Show 5 more

Open Access

https://doi.org/10.1021/acs.est.0c02715

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Abstract

The underlying mechanisms that influence microplastic ingestion in marine zooplankton remain poorly understood. Here, we investigate how microplastics of a variety of shapes (bead, fiber, and fragment), in combination with the algal-derived infochemicals dimethyl sulfide (DMS) and dimethylsulfoniopropionate (DMSP), affect the ingestion rate of microplastics in three species of zooplankton, the copepods Calanus helgolandicus and Acartia tonsa and larvae of the European lobster Homarus gammarus. We show that shape affects microplastic bioavailability to different species of zooplankton, with each species ingesting significantly more of a certain shape: C. helgolandicus-fragments (P < 0.05); A. tonsa-fibers (P < 0.01); H. gammarus larvae-beads (P < 0.05). Thus, different feeding strategies between species may affect shape selectivity. Our results also showed significantly increased ingestion rates by C. helgolandicus on all microplastics that were infused with DMS (P < 0.01) and by H. gammarus larvae and A. tonsa on DMS-infused fibers and fragments (P < 0.05). By using a range of more environmentally relevant microplastics, our findings highlight how the feeding strategies of different zooplankton species may influence their susceptibility to microplastic ingestion. Furthermore, our novel study suggests that species reliant on chemosensory cues to locate their prey may be at an increased risk of ingesting aged microplastics in the marine environment.

Highlights

Microplastic is abundant and widespread in the marine environment and has been identified as a contaminant of global environmental and economic concern.[1−3] The risks that larger plastic debris presents to marine organisms have been well documented,[4−7] yet there still remain knowledge gaps regarding the impact of microplastics.[1]
We investigate the effect of microplastic shape and the presence of the infochemicals DMSP and dimethyl sulfide (DMS) on microplastic ingestion by three species of zooplankton: the widely distributed suspension feeder C. helgolandicus, a temperate calanoid copepod and dominant mesozooplankton species in the North Atlantic; the globally distributed calanoid copepod Acartia tonsa, an ambush and suspension feeder; and the ambush feeder larvae of Homarus gammarus (European lobster) a species of both economic and social importance in the U.K
Our study reveals that both shape and the infusion of infochemicals can affect the ingestion rate of microplastics in

Summary

Introduction

Microplastic (microscopic plastic, 1 μm to 5 mm) is abundant and widespread in the marine environment and has been identified as a contaminant of global environmental and economic concern.[1−3] The risks that larger plastic debris presents to marine organisms have been well documented,[4−7] yet there still remain knowledge gaps regarding the impact of microplastics.[1]. Ingestion of microplastics has been recorded in many marine species including cetaceans,[13,14] seabirds,[15] molluscs,[16] and zooplankton.[17,18] In species at lower trophic levels, such as zooplankton, ingested microplastics have been shown to cause several detrimental effects, including reduced feeding behavior, growth, and fecundity.[19−21]

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