title: Mechanisms of Nickel Toxicity in the Highly Sensitive Embryos of the Sea Urchin Evechinus chloroticus, and the Modifying Effects of Natural Organic Matter.
abstract: A 96 h toxicity test showed that the embryos of the New Zealand sea urchin (Evechinus chloroticus) are the most sensitive of all studied marine species to waterborne nickel (Ni), with the EC50 for the development of fully formed pluteus larvae found to be 14 μg L(-1). Failure to develop a standard larval shape suggested skeletal impairment. Whole body ions (Na, Mg) increased with Ni exposure and calcium influx was depressed. The effects of natural organic matter (NOM) on Ni accumulation and toxicity were also examined in three different seawater sources (nearshore, offshore, and near the outlet of a "brown water" stream). At low dissolved organic carbon (DOC) concentrations the brown water NOM was protective against Ni toxicity, however at higher DOC concentrations it exacerbated developmental toxicity in the presence of Ni. These results show that sea urchin development is highly sensitive to Ni via a mechanism that involves ionoregulatory disturbance, and that Ni toxicity is influenced by environmental factors such as NOM. These data will be critical for the development of water quality guidelines for Ni in the marine environment.
authors.affiliation: Department of Biology, McMaster University , Hamilton, Ontario L8S 4K1, Canada.|Department of Chemistry Wilfrid Laurier University , Waterloo, Ontario N2L 3C5, Canada.
authors.forename: Tamzin A
authors.initials: TA
authors.lastname: Blewett
authors.affiliation: Department of Chemistry Wilfrid Laurier University , Waterloo, Ontario N2L 3C5, Canada.
authors.forename: D Scott
authors.initials: DS
authors.lastname: Smith
authors.affiliation: Department of Biology, McMaster University , Hamilton, Ontario L8S 4K1, Canada.|Department of Zoology, University of British Columbia , Vancouver, British Columbia V6T 1Z4, Canada.
authors.forename: Chris M
authors.initials: CM
authors.lastname: Wood
authors.affiliation: School of Biological Sciences, University of Canterbury , Christchurch, New Zealand.|Faculty of Science and Technology, Athabasca University , Athabasca, Alberta T9S 3A3, Canada.
authors.forename: Chris N
authors.initials: CN
authors.lastname: Glover
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian / Q000187:drug effects*; D000075322:Heavy Metal Poisoning; D006812:Humic Substances; D007814:Larva; D019216:Metals, Heavy / Q000494:pharmacology; D009520:New Zealand; D009532:Nickel / Q000633:toxicity*; D011041:Poisoning; D012617:Sea Urchins / Q000187:drug effects*; D012623:Seawater; D018675:Toxicity Tests; D014867:Water; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D006812:Humic Substances; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D014867:Water; D009532:Nickel