Experimental poisoning of the rainbow trout salmo gairdneri by engine diesel oil mortalities hematological changes histology
Poirier, A.; Baudin Laurencin, F.; Bodennec, G.; Quentel, C.
Aquaculture 55(2): 115-138
Rainbow trout were kept for 96 h in diesel oil contaminated waters: 100-2500 ml/m3 in five trials conducted with 0.3-1-g fry and 330-8300 ml/m3 in two trials with 150-250-g fish. The concentrations, measured by UV spectrofluorimetry, varied widely with time and took into account transitory emulsions. Consequently, the determination of lethal concentrations was only of relative significance. CL50 at 96 h would be about 100 ppm for fry. Haematological and histological studies were performed on surviving specimens. At the end of the poisoning, haemodilution, hyperglycemy, lymphopaenia, as well as lesions of the gills, gastric glands and exocrine pancreas, were observed and related to a stress reaction resulting from the pollutant. Anaemia and leucopaenia were still observed a week after poisoning; they may be caused by the toxic effect of hydrocarbons. The consequences of accidental pollution of a fish culture facility are discussed.