What is in a whale? 
     
    
   
   
    
     BY PIERRE—YVES DAOUST 
     
    
   
   
    
     I mean it literally. What is inside a whale that causes it to beach? 
     
     As a veterinary pathologist, a good part of my work involves trying to 
     
     answer three basic questions: what disease has caused a particular ani- 
     
     mal to die, why did this disease happen, and what is the potential sig— 
     
     nificance of this disease for the rest of the population of the particu— 
     
     lar species involved? 
     
    

    
     Because of my fascination for wildlife, I am most interested in an- 
     
     swering these questions when I am presented with a dead wild animal. 
     
     Wildlife diseases used to be considered a part of the natural mechanisms 
     
     controlling animal populations. However, because of the detrimental in- 
     
     fluence of human activity on natural habitats, many disease outbreaks are 
     
     now occurring among wild animals that should otherwise not have occurred. 
     
     For example, loss of habitat, which presently may represent the biggest 
     
     threat to wild- 
     
    
   
   
    
       
     
    
   
   
    
     life, not only 4a.. 
     
     causes a de— P 
     
     crease in popu- 
     
    

    
     lations of wild ’§" 
     
    
   
   
    
     animals, but 
     
     also forces the 
     
     remaining ani- 
     
     mals 
     
    
   
   
    
     in those de- 
     
     pressed popula— 
     
     tions to crowd 
     
     on the limited 
     
     habitat left, 
     
     thus increasing 
     
     the likelihood 
     
     of infectious 
     
     diseases to 
     
     occur. 
     
    

    
     Environ- 
     
     mental pollution 
     
     is, of course, 
     
     another impor- 
     
     tant example of 
     
     the harmful influence of human activity on wildlife. The plight of the St. 
     
     Lawrence population of belugas is a case in point. These animals have the 
     
     very dubious reputation of being the most polluted animals on earth, and 
     
     their population has declined steadily from about 1200 after commercial 
     
     harvesting ended in the 1950's to about 450 currently. Work by Pierre 
     
     Béland and Daniel Martineau in Quebec has documented the presence of more 
     
     than 30 chemicals in bodies of beached belugas, in conjunction with var— 
     
     ious diseases such as abscess, pneumonia, tumors, and reproductive failure. 
     
    

    
     Because the influence of environmental degradation on the occurrence 
     
     of wildlife diseases can be a subtle but nonetheless very serious one, it 
     
     becomes important to closely monitor the cause of mortality among wild 
     
     animals. Having obtained most of my training on wildlife diseases at the 
     
     University of Saskatchewan, to say that I had little exposure to marine