title: Toxic effects of polyethylene terephthalate microparticles and Di(2-ethylhexyl)phthalate on the calanoid copepod, Parvocalanus crassirostris.
abstract: Large amounts of plastic end up in the oceans every year where they fragment into microplastics over time. During this process, microplastics and their associated plasticizers become available for ingestion by different organisms. This study assessed the effects of microplastics (Polyethylene terephthalate; PET) and one plasticizer (Di(2-ethylhexyl)phthalate; DEHP) on mortality, productivity, population sizes and gene expression of the calanoid copepod Parvocalanus crassirostris. Copepods were exposed to DEHP for 48h to assess toxicity. Adults were very healthy following chemical exposure (up to 5120µg L-1), whereas nauplii were severely affected at very low concentrations (48h LC50value of 1.04 ng L-1). Adults exposed to sub-lethal concentrations of DEHP (0.1-0.3µg L-1) or microplastics (10,000-80,000 particles mL-1) exhibited substantial reductions in egg production. Populations were exposed to either microplastics or DEHP for 6 days with 18 days of recovery or for 24 days. Populations exposed to microplastics for 24 days significantly depleted in population size (60±4.1%, p<0.001) relative to controls, whilst populations exposed for only 6 days (with 18 days of recovery) experienced less severe depletions (75±6.0% of control, p<0.05). Populations exposed to DEHP, however, exhibited no recovery and both treatments (6 and 24 days) yielded the same average population size at the termination of the experiment (59±4.9% and 59±3.4% compared to control; p<0.001). These results suggest that DEHP may induce reproductive disorders that can be inherited by subsequent generations. Histone 3 (H3) was significantly (p<0.05) upregulated in both plastic and DEHP treatments after 6 days of exposure, but not after 18 days of recovery. Hsp70-like expression showed to be unresponsive to either DEHP or microplastic exposure. Clearly, microplastics and plasticizers pose a serious threat to zooplankton and potentially to higher trophic levels.
authors.affiliation: College of Marine & Environmental Sciences, James Cook University, 1 James Cook Drive, Townsville, Australia. Electronic address: franzmaximilian.heindler@kuleuven.be.
authors.forename: Franz M
authors.initials: FM
authors.lastname: Heindler
authors.affiliation: College of Marine & Environmental Sciences, James Cook University, 1 James Cook Drive, Townsville, Australia; Environment Public Authority Kuwait, P. O. Box 24395, Safat 13104, Kuwait.
authors.forename: Fahad
authors.initials: F
authors.lastname: Alajmi
authors.affiliation: College of Marine & Environmental Sciences, James Cook University, 1 James Cook Drive, Townsville, Australia.
authors.forename: Roger
authors.initials: R
authors.lastname: Huerlimann
authors.affiliation: College of Marine & Environmental Sciences, James Cook University, 1 James Cook Drive, Townsville, Australia; Centre of Sustainable Tropical Fisheries and Aquaculture, James Cook University, 1 James Cook Drive, Townsville, Australia.
authors.forename: Chaoshu
authors.initials: C
authors.lastname: Zeng
authors.affiliation: Western Australian Fisheries and Marine Research Laboratories, Department of Fisheries, Government of Western Australia, P.O. Box 20, North Beach, Western Australia 6920, Australia.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Newman
authors.affiliation: College of Science, Technology and Engineering, James Cook University, 1 James Cook Drive, Townsville, Australia.
authors.forename: George
authors.initials: G
authors.lastname: Vamvounis
authors.affiliation: College of Marine & Environmental Sciences, James Cook University, 1 James Cook Drive, Townsville, Australia; Centre of Sustainable Tropical Fisheries and Aquaculture, James Cook University, 1 James Cook Drive, Townsville, Australia; Comparative Genomics Centre, James Cook University, 1 James Cook Drive, Townsville, Australia.
authors.forename: Lynne
authors.initials: L
authors.lastname: van Herwerden
mesh_terms: D000818:Animals; D001315:Australia; D033342:Copepoda / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D004051:Diethylhexyl Phthalate / Q000737:chemistry / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D007928:Lethal Dose 50; D008297:Male; D010316:Particle Size; D010968:Plasticizers / Q000737:chemistry / Q000633:toxicity*; D010969:Plastics / Q000737:chemistry / Q000633:toxicity*; D011093:Polyethylene Terephthalates / Q000737:chemistry / Q000633:toxicity*; D012098:Reproduction / Q000187:drug effects; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*
chemical_list: D010968:Plasticizers; D010969:Plastics; D011093:Polyethylene Terephthalates; D014874:Water Pollutants, Chemical; D004051:Diethylhexyl Phthalate
keywords: DEHP; Microplastic; PET; Pollution; Zooplankton; qPCR