Toxicity of alkalinity to Hyalella azteca

Bulletin of Environmental Contamination and Toxicology
freshwater amphipod, no common name 5102 Lasier.pdf
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Toxicity testing and chemical analyses of sediment pore water have been suggested for use in sediment quality assessments and sediment toxicity identification evaluations. However, caution should be exercised in interpreting pore-water chemistry and toxicity due to inherent chemical characteristics and confounding relationships. High concentrations of alkalinity, which are typical of sediment pore waters from many regions, have been shown to be toxic to test animals. A series of tests were conducted to assess the significance of elevated alkalinity concentrations to Hyalella azteca, an amphipod commonly used for sediment and pore-water toxicity testing. Toxicity tests with 14-d old and 7-d old animals were conducted in serial dilutions of sodium bicarbonate (NaHCO3) solutions producing alkalinities ranging between 250 to 2000 mg/L as CaCO3. A sodium chloride (NaCl) toxicity test was also conducted to verify that toxicity was due to bicarbonate and not sodium. Alkalinity was toxic at concentrations frequently encountered in sediment pore water. There was also a significant difference in the toxicity of alkalinity between 14-d old and 7-d old animals. The average 96-h LC50 for alkalinity was 1212 mg/L (as CaCO3) for 14-d old animals and 662 mg/L for the younger animals. Sodium was not toxic at levels present in the NaHCO3 toxicity tests. Alkalinity should be routinely measured in pore-water toxicity tests, and interpretation of toxicity should consider alkalinity concentration and test-organism tolerance.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Toxicity of alkalinity to Hyalella azteca
Series title Bulletin of Environmental Contamination and Toxicology
Volume 59
Issue 5
Year Published 1997
Language English
Contributing office(s) Patuxent Wildlife Research Center
Description 807-814
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Bulletin of Environmental Contamination and Toxicology
First page 807
Last page 814
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