Acute and Chronic Toxicity of Copper to the Estuarine Copepod 'Eurytemoraaffinis'

摘要

The objectives of this study were to conduct (48 and 96h) and chronic (8d) coppertoxicity tests with the estuarine zooplankter, Eurytemora affinis and develop an acute to chronic ratio (ACR) for this species. Total dissolved copper, copper speciation and organic complexation were measured on selected samples during these toxicity tests. Determination of organic complexation was critical to determine the bioavailability of copper to the test species. Concentrations of total dissolved copper at selected test conditions displayed a loss of 20 to 35% over the course of the acute and chronic experiments with the most signficant loss occurring during the first 48 hours. Due to the reported loss of copper during exposures, a decay model was developed to calculate the concentrations that were used to determine the final toxicity values (adjusted copper concentrations). The 48h LC50, 96h LC50 and 8d chronic values were 83.0, 69,4 and 64 microgram/L dissolved copper, respectively, using the adjusted copper concentrations. An acute to chronic ratio of 1.3 was calculated using the 48 h and 8 d toxicity values.