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Seawater Inhibition of Nitrite Toxicity to Chinook Salmon
Author(s) -
Crawford Richard E.,
Allen George H.
Publication year - 1977
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1977)106<105:siontt>2.0.co;2
Subject(s) - methemoglobin , nitrite , methemoglobinemia , toxicity , seawater , liter , acute toxicity , chemistry , artificial seawater , environmental chemistry , hemoglobin , biology , nitrate , biochemistry , ecology , endocrinology , organic chemistry
The relative toxicity of nitrite to chinook salmon fingerlings (Oncorhynchus tshawytscha) in both freshwater ([Ca ++ ] = 32 mg liter −1 ) and natural seawater (32.5‰, [Ca ++ ] = 396 mg liter −1 ) was measured by 48‐h static bioassay. The percentage of hemoglobin oxidized to methemoglobin was also determined. In freshwater, the 48‐h median lethal nitrite concentration was 19 mg liter −1 . In natural seawater, 1,070 mg liter −1 nitrite caused only 10% mortality in 48 h. In freshwater with 27 mg NO 2 ‐ liter −1 , 44% methemoglobin occurred with 70% mortality. In natural saltwater with 815 mg NO 2 ‐ liter −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 calcium‐free artificial seawater (100 mg NO 2 ‐ liter −1 ) was highly toxic but did not induce appreciable methemoglobinemia. Adding calcium 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.