Additional data (Estrella, 1984) provide useful information in 

 terms of shell disease occurring at low levels in apparently 

 healthy lobster populations, but showing significantly increased 

 prevalence in areas of measurable environmental pollution (Figure 

 3). J. Rugg (1989, unpublished), began a study of perforating 

 lesions of the shell in lobsters of the New York Bight apex in 

 1986. Her initial sampling disclosed prevalences of shell 

 perforations averaging 14%. 



Information currently available suggests that the natural 

 occurrence of shell disease in lobsters may result from scratches, 

 abrasions, or wounds that expose underlying layers of the shell to 

 invasion by chitin digesting bacteria or fungi. It remains to be 

 determined, however, what role, if any, may be attributed to 

 microbial or chemical agents associated with waste disposal. 



14 



