Estimating the Acute Toxicity of Produced Waters to Marine Organisms Using Predictive Toxicity Models

Abstract

Common ions in effluents can be toxic to aquatic organisms over a wide range of salinities. Although the toxicity of high salinity (hypersaline) solutions and low salinity (hyposaline) solutions may be due to osmotic conditions, toxicity may also be the result of specific ion concentrations. Therefore, even in effluents of normal freshwater or marine salinity, common ion toxicity to aquatic organisms may occur in the absence of other toxicants. Little historical data exist on the toxicity of specific ions to freshwater or marine test organisms. Because of the paucity of data on the toxicity of common ions in produced waters, the Gas Research Institute (GRI) sponsored a research program to examine the toxicity of major ions to aquatic test organisms. The goal of this research is to quantify the relationships between common ion concentrations and organism response (mortality), and then to use these empirical relationships to develop models that would allow the prediction of organism response based upon known ion concentrations.