title: Microplastics Affect the Ecological Functioning of an Important Biogenic Habitat.
abstract: Biological effects of microplastics on the health of bivalves have been demonstrated elsewhere, but ecological impacts on the biodiversity and ecosystem functioning of bivalve-dominated habitats are unknown. Thus, we exposed intact sediment cores containing European flat oysters (Ostrea edulis) or blue mussels (Mytilus edulis) in seawater to two different densities (2.5 or 25 μg L-1) of biodegradable or conventional microplastics in outdoor mesocosms. We hypothesized that filtration rates of the bivalves, inorganic nitrogen cycling, primary productivity of sediment dwelling microphytobenthos, and the structure of invertebrate benthic assemblages would be influenced by microplastics. After 50 days, filtration by M. edulis was significantly less when exposed to 25 μg L-1of either type of microplastics, but there were no effects on ecosystem functioning or the associated invertebrate assemblages. Contrastingly, filtration by O. edulis significantly increased when exposed to 2.5 or 25 μg L-1of microplastics, and porewater ammonium and biomass of benthic cyanobacteria decreased. Additionally the associated infaunal invertebrate assemblages differed, with significantly less polychaetes and more oligochaetes in treatments exposed to microplastics. These findings highlight the potential of microplastics to impact the functioning and structure of sedimentary habitats and show that such effects may depend on the dominant bivalve present.
authors.affiliation: Department of Life Sciences, Anglia Ruskin University , Cambridge, United Kingdom , CB11PT.|School of Life Sciences, Gibbet Hill Campus, University of Warwick , Coventry, United Kingdom , CV47AL.|Biogeochemistry Research Group, Geography Department, School of Natural Sciences, Trinity College Dublin , Dublin 2, Ireland.
authors.forename: Dannielle Senga
authors.identifier: 0000-0002-9122-8160
authors.initials: DS
authors.lastname: Green
authors.affiliation: School of Life Sciences, Gibbet Hill Campus, University of Warwick , Coventry, United Kingdom , CV47AL.
authors.forename: Bas
authors.initials: B
authors.lastname: Boots
authors.affiliation: Queen's University Marine Laboratory, Portaferry, Northern Ireland, United Kingdom.|School of Biological Sciences, Queen's University Belfast , Northern Ireland, United Kingdom , BT71NN.
authors.forename: Nessa E
authors.initials: NE
authors.lastname: O'Connor
authors.affiliation: School of Marine Science and Engineering, Plymouth University , Plymouth, Devon, United Kingdom , PL48AA.
authors.forename: Richard
authors.initials: R
authors.lastname: Thompson
mesh_terms: D000818:Animals; D044822:Biodiversity; D004463:Ecology; D017753:Ecosystem; D049880:Mytilus edulis; D012623:Seawater / Q000737:chemistry