title: Toxicity of un-ionized ammonia, nitrite, and nitrate to juvenile bay scallops, Argopecten irradians irradians.
abstract: Juvenile bay scallops (7.2-26.4 mm) were exposed for 72 h to different concentrations of un-ionized ammonia, nitrite, or nitrate. Using the Trimmed Spearman Karber method, 50% lethal concentrations (LC(50)) and 95% confidence limits were calculated individually for each. Un-ionized ammonia concentrations above 1.0 mg N-NH(3)/L resulted in 100% scallop mortality within 72 h. The 72-h LC(50) for un-ionized ammonia was calculated at 0.43 mg N/L. At nitrite concentrations of 800 mg N/L or higher 100% mortality was observed. The 72-h LC(50) for nitrite was calculated at 345 mg N/L. Nitrate was the least toxic, with 100% mortality observed at a concentration of 5000 mg N/L. The calculated nitrate 72-h LC(50) was 4453 mg N/L. Our results indicate that un-ionized ammonia is the most lethal nitrogenous waste component to bay scallops.
authors.affiliation: NOAA/NMFS, 212 Rogers Ave., Milford, CT 06418, USA. jwidman@mi.nmfs.gov
authors.forename: James C
authors.initials: JC
authors.lastname: Widman
authors.forename: Shannon L
authors.initials: SL
authors.lastname: Meseck
authors.forename: George
authors.initials: G
authors.lastname: Sennefelder
authors.forename: David J
authors.initials: DJ
authors.lastname: Veilleux
mesh_terms: D000641:Ammonia / Q000633:toxicity*; D000818:Animals; D007928:Lethal Dose 50; D009566:Nitrates / Q000633:toxicity*; D009573:Nitrites / Q000633:toxicity*; D049897:Pectinidae / Q000187:drug effects*
chemical_list: D009566:Nitrates; D009573:Nitrites; D000641:Ammonia