title: Using an interlaboratory study to revise methods for conducting 10-d to 42-d water or sediment toxicity tests with Hyalella azteca.
abstract: Studies have been conducted to refine US Environmental Protection Agency, ASTM International, and Environment Canada standard methods for conducting 42-d reproduction tests with Hyalella azteca in water or in sediment. Modifications to the H. azteca method include better-defined ionic composition requirements for exposure water (i.e., >15 mg/L of chloride and >0.02 mg/L of bromide) and improved survival, growth, and reproduction with alternate diets provided as increased rations over time in water-only or whole-sediment toxicity tests. A total of 24 laboratories volunteered to participate in the present interlaboratory study evaluating the performance of H. azteca in 42-d studies in control sand or control sediment using the refined methods. Improved growth and reproduction of H. azteca was observed with 2 alternate diets of 1) ramped diatoms (Thalassiosira weissflogii) + ramped Tetramin or 2) yeast-cerophyll-trout chow (YCT) + ramped Tetramin, especially when compared with results from the traditional diet of 1.8 mg YCT/d. Laboratories were able to meet proposed test acceptability criteria and in most cases had lower variation in growth or reproduction compared with previous interlaboratory studies using the traditional YCT diet. Laboratory success in conducting 42-d H. azteca exposures benefited from adherence to several key requirements of the detailed testing, culturing, and handling methods. Results from the present interlaboratory study are being used to help revise standard methods for conducting 10-d to 42-d water or sediment toxicity exposures with H. azteca. Environ Toxicol Chem 2016;35:2439-2447. © 2016 SETAC.
authors.affiliation: US Geological Survey, Columbia, Missouri. civey@usgs.gov.
authors.forename: Chris D
authors.initials: CD
authors.lastname: Ivey
authors.affiliation: US Geological Survey, Columbia, Missouri.
authors.forename: Chris G
authors.initials: CG
authors.lastname: Ingersoll
authors.affiliation: US Geological Survey, Columbia, Missouri.
authors.forename: William G
authors.initials: WG
authors.lastname: Brumbaugh
authors.affiliation: US Environmental Protection Agency, Chicago, Illinois.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Hammer
authors.affiliation: US Environmental Protection Agency, Duluth, Minnesota.
authors.forename: Dave R
authors.initials: DR
authors.lastname: Mount
authors.affiliation: US Environmental Protection Agency, Duluth, Minnesota.
authors.forename: J Russell
authors.initials: JR
authors.lastname: Hockett
authors.affiliation: US Environmental Protection Agency, Duluth, Minnesota.
authors.forename: Teresa J
authors.initials: TJ
authors.lastname: Norberg-King
authors.affiliation: Illinois Natural History Survey, Champaign, Illinois, USA.
authors.forename: Dave
authors.initials: D
authors.lastname: Soucek
authors.affiliation: Environment Canada, Ottawa, Ontario, Canada.
authors.forename: Lisa
authors.initials: L
authors.lastname: Taylor
mesh_terms: D033304:Amphipoda / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D000818:Animals; D019015:Geologic Sediments / Q000737:chemistry*; D007753:Laboratories / Q000592:standards; D012098:Reproduction / Q000187:drug effects; D013997:Time Factors; D018675:Toxicity Tests / Q000379:methods* / Q000592:standards; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000633:toxicity*; D060753:Water Quality
chemical_list: D014874:Water Pollutants, Chemical
keywords: Hyalella azteca; Methods; Sediment testing; Water-only testing