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Puerto Rico

Status and distribution

Comprehensive aerial surveys were flown in August 1976 and almost every month between June 1978 and March 1979, and between March 1984 and March 1985, in conjunction with interviews with coastal residents. Distribution of manatees in Puerto Rico is uneven, with most manatees spotted along protected areas of the southern and northeastern coasts. Roughly a third of the sightings occurred in the area of Roosevelt Roads Naval Station (RRNS) (Powell et al. 1981, Rathbun et al. 1985). Second in sighting frequencies is Jobos Bay in Guayama, and areas such as Guayanilla, Bahía Montalva, Joyuda, Cabo Rojo, Guanajibo, Toa Baja, Ocean Park, Loiza and Rio Grande are of tertiary importance. Around RRNS, half of the sightings occurred west of Isla Cabras (especially Pelican Cove and Ensenada Honda) and a quarter in northwestern Vieques Island (Rathbun et al. 1985). Similarities between results of the two aerial survey studies indicate that the Puerto Rico manatee population is at least not declining (Lefebvre et al. 1989). Highest counts were 51 in the first survey and 62 in the second; average number sighted was 22.6 and 43.6, and percentage of calves was 6.4% and 7.6% respectively (Powell et al. 1981, Rathbun et al. 1985). Seventy-four (74) were sighted on the latest survey in l993 (Carr, unpbl. data).

Major threats and conservation problems

In the past 17 years, up to 8 manatee deaths have been reported each year in Puerto Rico (excluding poaching for meat). Direct takes represent the major source of mortality among the manatee population (25.3%), followed by watercraft-related fatalities, including jet skis (18%) and incidental entanglements in nets (7.4%) (Mignucci-Giannonni 1989). Some entanglement may result from nets being set intentionally to catch both manatees and sea turtles; animals are often slaughtered after becoming entangled (Powell et al. 1981, Rathbun et al. 1985).

National legislation and conservation measures

Manatees in Puerto Rico receive protection from several Commonwealth of Puerto Rico laws (Ley de Pesca del Estado Libre Asociado of 1936, Ley de Vida Silvestre of 1976, and the Commonwealth of Puerto Rico Vulnerable and Endangered Species Management Regulation of 1985), and the U. S. Marine Mammal Protection Act and the Endangered Species Act (Lefebvre et al. 1989, Mignucci-Giannonni 1989). Those animals using Roosevelt Roads Naval Station and Jobanes National Estuarine Research Reserve, are partially protected by the restrictions imposed by federal agencies (Rathbun and Possardt 1986). The United States of America (which includes Puerto Rico) is Party to the CITES Convention since 1975 and has signed but not ratified the SPAW Protocol.

A recovery plan for the Puerto Rican population of manatees has been prepared (Rathbun and Possardt 1986) with the final objective of downlisting the species. The plan, which describes a series of recommendations in the areas of research, conservation and law enforcement is just beginning to be implemented. The Caribbean Stranding Network (Red Caribeña de Varamientos or RCV) co-ordinates the rescue and rehabilitation of orphaned and injured animals, and the salvage of dead manatees in Puerto Rico and the Caribbean region. RCV is also very active in environmental education and promotes lectures and ecological activities related to the conservation of turtles and marine mammals. In April 1992, the U.S. Fish and Wildlife Service initiated a feasibility study of radio-tracking manatees in Puerto Rico. To date, 6 manatees have been captured at RRNS and released with satellite-monitored radio transmitters.

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