title: Feeding response in marine copepods as a measure of acute toxicity of four anti-sea lice pesticides.
abstract: Anti-sea lice pesticides used in salmon aquaculture are released directly into the environment where non-target organisms, including zooplankton, may be exposed. The toxicity of four pesticides to field-collected copepods was examined in 1-h exposures with lethality and feeding endpoints determined 5-h post-exposure using staining techniques. Copepods were immobilized within 1 h, at aquaculture treatment concentrations of deltamethrin (AlphaMax), cypermethrin (Excis), and hydrogen peroxide (InteroxParamove50). All organisms showed vital staining, indicating immobilized organisms were still alive, thus LC50s were not determined. Feeding on carmine particles was inhibited and EC50s ranged from 0.017 to 0.067 μg deltamethrin/L, 0.098-0.36 μg cypermethrin/L, and 2.6-10 mg hydrogen peroxide/L, representing 30- to 117-fold, 13- to 51-fold, and 120- to 460-fold dilutions of the respective aquaculture treatments. No effects were observed in copepods exposed to azamethiphos (Salmosan) at 5-times the aquaculture treatment. Acute exposure to three of the four pesticides affected feeding and mobility of copepods at environmentally-realistic concentrations.
authors.affiliation: Fisheries and Oceans Canada, St. Andrews Biological Station, 531 Brandy Cove Road, St. Andrews, New Brunswick E5B 2L9, Canada; University of New Brunswick, Canadian Rivers Institute & Biology Department, 100 Tucker Park Road, Saint John, New Brunswick E2L 4L5, Canada. Electronic address: jordanavangeest@gmail.com.
authors.forename: Jordana L
authors.initials: JL
authors.lastname: Van Geest
authors.affiliation: Fisheries and Oceans Canada, St. Andrews Biological Station, 531 Brandy Cove Road, St. Andrews, New Brunswick E5B 2L9, Canada.
authors.forename: Les E
authors.initials: LE
authors.lastname: Burridge
authors.affiliation: Fisheries and Oceans Canada, St. Andrews Biological Station, 531 Brandy Cove Road, St. Andrews, New Brunswick E5B 2L9, Canada.
authors.forename: Frederick J
authors.initials: FJ
authors.lastname: Fife
authors.affiliation: University of New Brunswick, Canadian Rivers Institute & Biology Department, 100 Tucker Park Road, Saint John, New Brunswick E2L 4L5, Canada.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Kidd
mesh_terms: D000818:Animals; D017756:Aquaculture; D033342:Copepoda / Q000187:drug effects / Q000502:physiology*; D005247:Feeding Behavior / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000633:toxicity; D009570:Nitriles / Q000633:toxicity; D063086:Organothiophosphates / Q000633:toxicity; D010575:Pesticides / Q000633:toxicity*; D011722:Pyrethrins / Q000633:toxicity; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D009570:Nitriles; D063086:Organothiophosphates; D010575:Pesticides; D011722:Pyrethrins; D014874:Water Pollutants, Chemical; C017160:cypermethrin; C017180:decamethrin; C072763:azamethiphos; D006861:Hydrogen Peroxide
keywords: Aquaculture; Azamethiphos; Cypermethrin; Deltamethrin; Ecotoxicology; Hydrogen peroxide; Pulse exposure; Zooplankton