Acute and postexposure effects of ammonia toxicity on juvenile barramundi (Lates calcarifer [Bloch]).
Lethal and sublethal effects of ammonia toxicity to juvenile barramundi (Lates calcarifer) were investigated under laboratory conditions following the OECD guidelines for testing of chemicals. Acute toxicity was tested in a static nonrenewal system at pH 9.0 and temperature around 29 degrees C. The 24-, 48-, and 96-h LC(50) values for barramundi were 3.89, 3.67, and 3.31 mg total ammonia N L(-1) and 1.59, 1.47, and 1.3 mg nonionized ammonia N L(-1), respectively. Estimated lethal concentrations indicated a relatively high sensitivity to acute ammonia toxicity for barramundi and equaled the 25th percentile most sensitive North American fish species with regard to the species mean acute value (USEPA 1999). A 3-week postexposure experiment on surviving individuals from the acute toxicity test, in clean water, indicated that exposure to acute concentrations up to 1.16 mg nonionized ammonia N L(-1) did not have any significant effects on growth.
Okelsrud
Asle
A
School of Marine and Tropical Biology, James Cook University, 4811, Townsville, Queensland, Australia. lasiodo@hotmail.com
Pearson
Richard G
RG
D000641:Ammonia / Q000633:toxicity*; D000818:Animals; D005399:Fishes; D006128:Growth / Q000187:drug effects; D023382:Toxicity Tests, Acute; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D014874:Water Pollutants, Chemical; D000641:Ammonia