to do so. In the six years prior to 1984, total known manatee 

 mortality in the United States averaged 91 animals per year. 

 Since 1984, it has averaged 135 animals per year. In 1989 a 

 record high 174 animals were confirmed as having died. Such 

 mortality is alarming, given the approximate number of animals in 

 the southeast United States and the inherently low calving rate 

 of female manatees (i.e. , about one calf every two to three years 

 or more) . 



Known Manatee Mortality in the United States Reported 

 through the Manatee Salvage and Necropsy Program 



from 1978-1989 



Total No. 



of Deaths 



in U.S. 



84 



78 



67 

 116 

 123 



80 

 131 

 129 

 125 

 118 

 134 

 174 



* = Preliminary totals provided by the Florida 

 Department of Natural Resources 



Almost all of the increased mortality observed in recent 

 years can be attributed to increases in two mortality categories: 

 deaths caused directly by boats and barges; and dependent calf 

 deaths. The number of deaths in each of these two categories 

 reached record high levels in 1989 and, in each category, 

 previous records have been egualed or exceeded in five of the 

 past six years. Vessel-related and dependent calf deaths in 1989 

 were over twice the levels in the early 1980s. Carcasses 

 classified as vessel-related deaths are those with slashes or 

 other massive injuries obviously caused by propellers or by being 

 crushed by vessel hulls. Between 1978 and 1983, vessel-related 

 mortality averaged 20 animals per year. Since 1984, it has 

 averaged 39 manatees per year. 



Dependent calf deaths include carcasses of newborn or very 

 young animals. Although the precise cause of death is rarely 

 apparent, it is possible that recent increases in this mortality 



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