Physicochemical factors affecting the sensitivity of Ceriodaphnia dubia to copper

S. D. Kim, M. B. Gu, H. E. Allen, D. K. Cha

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


The effects of physicochemical conditions, such as pH, water hardness, flow rates and natural organic substances on the sensitivity of Ceriodaphnia dubia to the toxic effects of copper were investigated using static bioassay cups and specially designed flow-through bioassay chambers. We found that C. dubia was very sensitive to pH changes and the total copper LC50 values of C. dubia neonates increased by 15-fold as the pH increased from pH 7 to 10. It was also observed that the LC50 values increased sharply upon increasing the water hardness value to 2.4 meq. In addition, increasing flow rates from zero to 50 mL hr-1 also increased its sensitivity to copper, which was possibly due to hydrodynamic stress. The presence of natural organic substances (humic acid and dissolved organic matter) and suspended particles decreased the toxic effect of copper. This significant decrease in the toxicity of copper in the presence of natural organic materials can be explained by a reduction in the free ion concentration due to complexation. Furthermore, we observed that the kinetics of copper interactions with natural organic materials are a significant factor in the toxic effect of copper and that the acute LC50 values increased with increasing reaction time between solubilized copper and water-borne organics.

Original languageEnglish
Pages (from-to)105-116
Number of pages12
JournalEnvironmental Monitoring and Assessment
Issue number1-2
Publication statusPublished - 2001
Externally publishedYes


  • Complexation
  • Copper
  • Natural organic substances
  • Reaction time
  • Toxicity

ASJC Scopus subject areas

  • Environmental Science(all)
  • Pollution
  • Management, Monitoring, Policy and Law


Dive into the research topics of 'Physicochemical factors affecting the sensitivity of Ceriodaphnia dubia to copper'. Together they form a unique fingerprint.

Cite this