title: Use of Ulva lactuca to identify ammonia toxicity in marine and estuarine sediments.
abstract: Toxicity identification evaluation (TIE) methods are being developed for use with whole sediments. Although a phase I TIE method has been developed to characterize ammonia toxicity in aqueous samples using the marine macroalga Ulva lactuca, the relationship between amphipod and mysid mortality and uptake by U. lactuca of bedded sediment ammonia had not been explored. Additionally, it was not known how interactions in whole sediments between metal and organic contaminants with U. lactuca and ammonia would affect TIE interpretation. The current study showed that ammonia toxicity to amphipods and mysids was reduced significantly in marine sediments in the presence of U. lactuca. The alga slightly affected metal concentrations but did not alter the concentration of organic contaminants in either overlying or interstitial waters. Conversely, ammonia uptake by U. lactuca was not affected by the presence of metal or organic contaminants in the sediments. When used with other TIE manipulations, U. lactuca can be utilized in a whole-sediment, phase I TIE to remove toxicity due to ammonia.
authors.affiliation: U.S. Environmental Protection Agency, National Health and Environmental Effects Laboratory, Atlantic Ecology Division, Narragansett, Rhode Island 02882., USA. pelletier.peg@epa.gov
authors.forename: M C
authors.initials: MC
authors.lastname: Pelletier
authors.forename: K T
authors.initials: KT
authors.lastname: Ho
authors.forename: M
authors.initials: M
authors.lastname: Cantwell
authors.forename: A
authors.initials: A
authors.lastname: Kuhn-Hines
authors.forename: S
authors.initials: S
authors.lastname: Jayaraman
authors.forename: R M
authors.initials: RM
authors.lastname: Burgess
mesh_terms: D000641:Ammonia / Q000493:pharmacokinetics* / Q000633:toxicity*; D000818:Animals; D001682:Biological Availability; D049872:Bivalvia; D000460:Chlorophyta; D003445:Crustacea; D004781:Environmental Exposure; D019015:Geologic Sediments / Q000737:chemistry*; D018675:Toxicity Tests; D014873:Water Pollutants / Q000493:pharmacokinetics* / Q000633:toxicity*
chemical_list: D014873:Water Pollutants; D000641:Ammonia