Exposure of Atlantic Salmon Parr (Salmo Salar) to a Combination of Resin Acids and a Water Soluble Fraction of Diesel Fuel Oil: A Model to Investigate the Chemical Causes of Pigmented Salmon Syndrome

Abstract

Abstract-Pigmented Salmon Syndrome is a pollutant-induced hemolytic anemia and hyperbilirubinemia. As part of an investigation of this condition, S2 Atlantic salmon parr (Salmo salar) were exposed to a diesel fuel oil, water soluble fraction (WSF) in combination with a mixture of three resin acids (isopimaric, dehydroabietic, and abietic acids) in a continuous-flow freshwater system. The total nominal concentrations of resin acids in the exposure tanks were 10, 50, and 100 g/L; the diesel WSF was generated in situ and provided a mean hydrocarbon concentration of 2.0 Ϯ 0.1 mg/L (n ϭ 12) during the 9-d exposure period. Exposure to the diesel WSF alone depressed liver bilirubin UDP-glucuronosyl transferase (UDPGT) activity and induced phenol UDPGT activity. Exposure to the diesel WSF in the absence or presence of resin acids induced liver cytochrome P4501A and increased the concentrations in the plasma of the enzymes lactate dehydrogenase, alkaline phosphatase, and glutamic oxaloacetic transaminase. The combined exposure to diesel WSF with either 50 or 100 g/L total resin acid caused significant elevations in the concentrations of bilirubin in the plasma and many of these fish had yellow pigmentation on the ventral surface and around the gill arches. The results demonstrate that exposure to combinations of two groups of contaminants can result in the manifestation of toxic effects not apparent from exposure to either of these chemicals in isolation.

Oil toxicity test methods must be improved

“…This system provides constant oil concentrations for prolonged experiments but requires high volumes of water and oil. On a smaller scale, fresh or weathered oil was mixed with water by peristaltic pumps and in‐line mixers (Croce and Stagg ), although interactions between oil and plastic peristaltic tubing may limit this approach to brief experiments.…”

Biosensing the acute toxicity of metal interactions: Are they additive, synergistic, or antagonistic?

“…However, serious consequences may result when such assumptions are incorrect. For example, the manifestation of Pigmented Salmon Syndrome in Atlantic salmon of the River Don in Scotland, which reached epidemic proportions in the early 1980s, was a result of the synergistic interaction of the toxins found in two effluent discharges into the river [3, 4].…”