Chapter III 
SPECIES OF SPECIAL CONCERN 
Section 202 of the Marine Mammal Protection Act 
directs the Marine Mammal Commission, in consulta- 
tion with its Committee of Scientific Advisors on 
Marine Mammals, to make recommendations to the 
Department of Commerce, the Department of the 
Interior, and other agencies on actions that should be 
taken to protect marine mammals. To help meet this 
charge, the Commission devotes special attention to 
species, populations, or habitats that are particularly 
vulnerable. Species of special concern may include 
marine mammals listed as endangered or threatened 
under the Endangered Species Act (Table 1), as well 
as others. 
During 1992 special attention was directed to some 
of the endangered or threatened species in U.S. waters 
and to others that are either in other countries’ waters 
or are shared with other countries. These included 
West Indian manatees, California (southern) sea 
otters, Hawaiian monk seals, Steller sea lions, north- 
ern right whales, humpback whales, bowhead whales, 
gray whales, and vaquitas (Gulf of California harbor 
porpoises). Special attention also was devoted to 
other U.S. species or populations not listed but faced 
with serious problems. Among these are sea otters in 
Alaska, harbor seals, northern fur seals, Pacific 
walruses, harbor porpoises, bottlenose dolphins, killer 
whales, and polar bears. 
West Indian Manatee 
(Trichechus manatus) 
The West Indian manatee is one of the most endan- 
gered marine mammals in the United States. It was 
among the first species so listed under the Endangered 
Species Preservation Act of 1966, a predecessor to the 
Endangered Species Act of 1973. In the United 
States, manatee populations occur in the southeastern 
states — primarily in Florida and Georgia — and in 
Puerto Rico. In the southeastern states, manatees are 
recognized as a separate subspecies, 7. manatus 
latirostris, also called the Florida manatee. The 
manatee population in Puerto Rico, estimated to 
number perhaps 100 animals, belongs to the only 
other recognized subspecies, 7. manatus manatus, 
also called the Antillean manatee. 
The manatee population in the southeastern United 
States is the largest known group anywhere in the 
species’ range. Based on a synoptic survey organized 
by the Florida Department of Natural Resources in 
January 1992, the population is known to number at 
least 1,856 animals. Of these, roughly half occur 
along the western coast of Florida and the other half 
along the eastern coast. 
Although overall population trends in the south- 
eastern United States and Puerto Rico are uncertain, 
it is likely both groups are either stable or declining. 
Collisions with boats and habitat destruction are the 
major threats in Florida and Georgia; habitat de- 
struction and incidental catch in gillnets appear to be 
the primary threats in Puerto Rico. 
Outside the United States, West Indian manatees 
are found in the Greater Antilles, along the Caribbean 
coast of Central and South America, in Trinidad and 
Tobago, and along the South American coast as far 
south as Recife, Brazil. In most of these areas, 
remaining populations are believed to be small. 
Poaching for food, incidental catch in gillnets, and 
habitat loss are among the most serious threats. 
Because most countries lack concerted manatee protec- 
tion programs, the species’ long-term survival may 
well depend on the success of efforts to protect 
remaining animals in Florida and Georgia. 
The future of the southeastern U.S. population, 
however, is uncertain because of steadily increasing 
mortality since 1980 (Table 2). Most of this is due to 
increases in vessel-related deaths and perinatal (i.e., 
