Dr. Rasul Khan
Effects of parasites and pollutants on marine fish: R. Khan.
The focus of this program is to determine the long-term effects of parasites on fish health and synergism between parasites and pollutants, such as petroleum hydrocarbons (PHCs) and effluent from pulp and paper mills, as bioindicators of chronic stress. Preliminary studies on four species of benthic fish inhabiting the Grand Banks, where millions of litres of bilge water have been discarded over many decades, have revealed pathological lesions in several organs whereas little evidence of this was observed in the same species sampled about 25 years previously. Moreover, ectoparasites appear to have increased in three species where as, endoparsites were sparse. Some evidence of increased detoxifying enzyme activity was observed in two of the four species, suggestive of exposure to PHCs. Additional studies are also examining the effects of ectoparasites on cultured Atlantic halibut, Atlantic cod and winter flounder in the laboratory. Reduced feed intake, impaired growth and mortality have been observed in all three fish species. The live fish used in these experiments were obtained from fish cultured in the laboratory.