Seawater Inhibition of Nitrite Toxicity to Chinook Salmon
- 1 January 1977
- journal article
- research article
- Published by Oxford University Press (OUP) in Transactions of the American Fisheries Society
- Vol. 106 (1) , 105-109
- https://doi.org/10.1577/1548-8659(1977)106<105:siontt>2.0.co;2
Abstract
The relative toxicity of nitrite to chinook salmon fingerlings (Oncorhynchus tshawytscha) in both freshwater ([Ca++] = 32 mg l-1) and natural seawater (32.5.permill., [Ca++] = 396 mg l-1) was measured by 48 h static bioassay. The percentage of Hb oxidized to methemoglobin was also determined. In freshwater, the 48 h median lethal nitrite concentration was 19 mg l-1. In natural seawater, 1070 mg l-1 nitrite caused only 10% mortality in 48 h. In freshwater with 27 mg NO2- l-1, 44% methemoglobin occurred with 70% mortality. In natural saltwater with 815 mg NO2- l-1, 74% methemoglobin occurred with 10% mortality. Adding calcium sulfate to the freshwater decreased the toxicity of nitrite but did not reduce methemoglobinemia. Nitrite in Ca free artificial seawater (100 mg NO2- l-1) was highly toxic but did not induce appreciable methemoglobinemia. Adding Ca to this medium decreased the acute toxicity of nitrite. These results suggest nitrite toxicity mortalities resulted from a cause(s) other than methemoglobinemia. The presence of another antagonistic ion(s) in seawater to nitrite toxicity is also suggested.This publication has 0 references indexed in Scilit: