Acute exposures of salmonid embryos to total dissolved solids

Abstract

Two exposure methodologies are described here utilizing embryonic and juvenile life stages of several species of salmonids. Specific life stages of the fish were exposed to solutions of varying total dissolved solids (TDS) modeled after the measured produced water from the Red Dog Mine in Kotzebue, Alaska. Embryonic and juvenile coho salmon (0. kisutch) were exposed for 96 hours to determine acute response to TDS. Following exposure, fish were grown out to button up to assess delayed effects. Results from the 96-hour study suggest fertilization is the most sensitive developmental stage of salmon exposed to TDS. Six fish species were then used to assess a new 24-hour embryo toxicity study during fertilization. We examined short- and long-term mortality, number of unfertilized eggs, and the overall percent affected. The endpoint for the assay is the success of egg fertilization. Based on the results of these experiments, it is reasonable to conclude that the fertilization assay can be generalized across these species and may be useful in setting site-specific criteria for discharging wastes.