category also are vessel-related. Virtually all adult animals 

 bear wounds or scars from non-lethal collisions with boats, and 

 it is reasonable to assume that at least some females with 

 nursing calves are struck and killed or injured by boats. Even 

 if they are not killed by boats, it is unlikely that severely 

 injured mothers would be able to tend their calves. In addition, 

 mother-calf pairs may become confused and separated when exposed 

 to heavy boat traffic. Young calves unable to relocate their 

 mothers likely would die. An average of 13 newborn and dependent 

 calf carcasses were recovered per year between 1979 and 1983. 

 Since then the number has averaged 29 animals per year. 



Coincident with increasing vessel-related and perinatal 

 deaths has been a substantial increase in the number and speed of 

 boats in Florida. Early in the 1960s, about 100,000 commercial 

 and recreational boats were registered in Florida. Typical top 

 speeds at that time were about 30 MPH. The number of registered 

 boats now exceeds 750,000 vessels, and about 3 00,000 additional 

 boats enter Florida from out-of-state each year. Many boats now 

 travel at speeds of 50 to 60 MPH, with some exceeding 80 and even 

 100 MPH. With more boats travelling at higher speeds, the 

 probability of animals being struck is greatly increased. There 

 is no guestion that the increase in manatee mortality is, in 

 part, a reflection of changes in the types and numbers of boats. 



A second major threat to manatees is degradation and loss of 

 remaining habitat due to coastal development. Florida's net 

 population growth has increased to about 1,000 people per day. 

 Accompanying this growth has been an unprecedented increase in 

 development, particularly along rivers and coastal shorelines. 

 Development in or adjacent to important manatee habitat can cause 

 siltation, other forms of water pollution, and direct removal and 

 preemption of natural vegetation. This, in turn, can reduce 

 manatee food supplies and eliminate natural secluded areas 

 preferred for calving, nursing, or mating. In the long term, 

 habitat losses due to increasing coastal development and 

 environmental pollution may well be a more serious threat to 

 manatees than vessel traffic. 



Background on Recovery Activities 



Late in the 1970s, a major effort was undertaken to develop 

 an effective manatee recovery program. Among other things, the 

 Marine Mammal Commission undertook a thorough review of Federal, 

 State, and private manatee conservation activities. Based on its 

 review, the Commission allocated a special Fiscal Year 1980 

 Congressional appropriation of $100,000 to critically needed 

 manatee research and management tasks. Also in 1980, the Fish 

 and Wildlife Service completed and adopted the West Indian 

 Manatee Recovery Plan. As recommended by the Commission, the 

 Plan was further supplemented by a Comprehensive Work Plan 

 adopted by the Service early in 1982. 



15 



