Ecotoxicological determination of pigmented salmon syndrome. A pathological condition of Atlantic salmon associated with river pollution

Pigmented salmon syndrome is described in this review. It is a non-infectious haemolytic anaemia with associated clinical jaundice of Atlantic salmon (Salmo salar), caused by exposure to a combination of chemical pollutants. The disease has been restricted to the migrating adult Atlantic salmon population of the River Don, Aberdeenshire, Scotland, UK, where it reached epidemic proportions in the early 1980s. Effluents from paper mills, from the oil-servicing industry and from an airport were implicated as causative factors in the syndrome. Subsequent experiments showed that symptoms of the syndrome could be reproduced by the sequential or combined exposure to petroleum hydrocarbons (such as diesel) and resin acids. The pigmented salmon syndrome has not recurred in wild River Don salmon since 1989. Research suggests that this is due to directed improvements in the water quality of the River Don. The disease appears to be an example of how multiple contaminants can collectively cause biological effects which are not apparent from exposure to single substances..