title: Microplastics Alter the Properties and Sinking Rates of Zooplankton Faecal Pellets.
abstract: Plastic debris is a widespread contaminant, prevalent in aquatic ecosystems across the globe. Zooplankton readily ingest microscopic plastic (microplastic, < 1 mm), which are later egested within their faecal pellets. These pellets are a source of food for marine organisms, and contribute to the oceanic vertical flux of particulate organic matter as part of the biological pump. The effects of microplastics on faecal pellet properties are currently unknown. Here we test the hypotheses that (1) faecal pellets are a vector for transport of microplastics, (2) polystyrene microplastics can alter the properties and sinking rates of zooplankton egests and, (3) faecal pellets can facilitate the transfer of plastics to coprophagous biota. Following exposure to 20.6 μm polystyrene microplastics (1000 microplastics mL(-1)) and natural prey (∼1650 algae mL(-1)) the copepod Calanus helgolandicus egested faecal pellets with significantly (P < 0.001) reduced densities, a 2.25-fold reduction in sinking rates, and a higher propensity for fragmentation. We further show that microplastics, encapsulated within egests of the copepod Centropages typicus, could be transferred to C. helgolandicus via coprophagy. Our results support the proposal that sinking faecal matter represents a mechanism by which floating plastics can be vertically transported away from surface waters.
authors.affiliation: College of Life and Environmental Sciences, University of Exeter , Exeter EX4 4QD, United Kingdom.|Plymouth Marine Laboratory , Plymouth PL1 3DH, United Kingdom.
authors.forename: Matthew
authors.initials: M
authors.lastname: Cole
authors.affiliation: Plymouth Marine Laboratory , Plymouth PL1 3DH, United Kingdom.
authors.forename: Penelope K
authors.initials: PK
authors.lastname: Lindeque
authors.affiliation: Plymouth Marine Laboratory , Plymouth PL1 3DH, United Kingdom.
authors.forename: Elaine
authors.initials: E
authors.lastname: Fileman
authors.affiliation: College of Life and Environmental Sciences, University of Exeter , Exeter EX4 4QD, United Kingdom.|Plymouth Marine Laboratory , Plymouth PL1 3DH, United Kingdom.
authors.forename: James
authors.initials: J
authors.lastname: Clark
authors.affiliation: College of Life and Environmental Sciences, University of Exeter , Exeter EX4 4QD, United Kingdom.
authors.forename: Ceri
authors.initials: C
authors.lastname: Lewis
authors.affiliation: Akvaplan-niva AS, FRAM -High North Research Centre for Climate and the Environment, N-9296 Tromsø, Norway.
authors.forename: Claudia
authors.initials: C
authors.lastname: Halsband
authors.affiliation: College of Life and Environmental Sciences, University of Exeter , Exeter EX4 4QD, United Kingdom.
authors.forename: Tamara S
authors.initials: TS
authors.lastname: Galloway
mesh_terms: D000818:Animals; D059001:Aquatic Organisms; D033342:Copepoda / Q000187:drug effects* / Q000378:metabolism; D003303:Coprophagia; D017753:Ecosystem; D005243:Feces / Q000737:chemistry*; D010969:Plastics / Q000737:chemistry / Q000493:pharmacokinetics*; D011137:Polystyrenes / Q000493:pharmacokinetics; D014874:Water Pollutants, Chemical / Q000493:pharmacokinetics*; D015048:Zooplankton / Q000187:drug effects*
chemical_list: D010969:Plastics; D011137:Polystyrenes; D014874:Water Pollutants, Chemical