distribution, abundance, and local concentrations of manatees 

 along the southern coast of Puerto Rico and to review past 

 sighting records, develop a questionnaire, and interview 

 knowledgeable persons to determine, as possible, the historic 

 distribution and abundance of manatees in Puerto Rico. The 

 report, due in March 1989, is expected to recommend a program 

 for assessing, monitoring, and conserving manatees and their 

 habitat in Puerto Rico. 



Die-off of Bottlenose Dolphins 



As noted in Chapter IV, unusual numbers of bottlenose 

 dolphins died and washed up on Atlantic coast beaches between 

 June 1987 and January 1988. The Commission initiated and 

 coordinated a comprehensive investigation of the die-off, 

 elements of which continued throughout 1988. In 1988, the 

 Commission, the National Marine Fisheries Service, and the 

 Navy provided funds in support of the investigation. The 

 following projects were supported by the Commission. 



Analysis of Bacteria and Fungi Isolated from Tissues of Dead 

 Bottlenose Dolphins 



(D.J. St. Aubin, Ontario Veterinary College, University of 

 Guelph, Guelph, Ontario, Canada) 



To assist in identifying the possible cause or causes of 

 the die-off of bottlenose dolphins along the U.S. east coast 

 in 1987 and 1988, the Commission provided funds to the 

 University of Guelph to undertake detailed histopathologic 

 studies of tissue samples from 60 dead bottlenose dolphins to 

 determine the species or types of bacteria and fungi present 

 in the tissues. Preliminary evidence from these studies, 

 combined with the pattern of dolphin mortality, suggest that 

 the bacterial and fungal organisms present were not primarily 

 responsible for the death of the infected animals and more 

 likely were opportunists, able to infect an animal once it 

 had been weakened by stress or other circumstances which 

 suppress the immune system. 



Viroloqical Analysis of Tissue Samples from Dead Bottlenose 



Dolphins 



(K.D. Somers, Ph.D., Eastern Virginia Medical School, Norfolk, 



Virginia) 



Isolation and characterization of viruses present in 

 tissues and lesions from affected dolphins was necessary to 

 determine whether viral infection caused the unusual mortality 

 of bottlenose dolphins off the mid-Atlantic coast in 1987-1988. 

 To initiate and support the needed analyses, the Commission 



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