MARINE MAMMAL COMMISSION — Annual Report for 1992 
Alaska Killer Whale Species Account 
As noted above, there are many uncertainties 
concerning the status of killer whales and what can 
and should be done to minimize the effect of human 
activities on the species in Alaska. To clearly define 
these uncertainties and help assess what might be done 
to resolve them, the Commission contracted in 1991 
for the preparation of a species account, with research 
and management recommendations, on killer whales 
in Alaska. The draft report was undergoing final 
review and editing at the end of 1992 and is expected 
to be published early in 1993 as an addition to the 
series of Alaska marine mammal species accounts 
published in 1988 (see Appendix B, Lentfer 1988). 
The final killer whale report will address research 
needs and priorities for investigating stock structure, 
pod size and composition, and habitat-use patterns. 
The report will also review and make recommenda- 
tions on actions to minimize direct and indirect 
interactions between killer whales and commercial 
fisheries; assess contaminant uptake and other impacts 
related to offshore oil and gas development and 
transportation and other industrial activities; and 
address possible effects of whale-watching activities 
and the tour boat industry in Prince William Sound, 
southeast Alaska, and other popular tourist areas. 
When completed, the Commission plans to forward 
the report to the National Marine Fisheries Service 
with recommendations based on the report’s findings. 
Vaquita 
(Phocoena sinus) 
The vaquita, or Gulf of California harbor porpoise, 
is one of the rarest and least known of all small 
cetaceans. Found only in the northern Gulf of Cali- 
fornia or Sea of Cortez in Mexico, it has the most 
limited range of any marine cetacean. The species 
was first described taxonomically in 1958 and, prior 
to 1984, there were fewer than 20 records of animals 
either having been seen alive or recovered dead. 
Between 1986 and 1989 researchers from the 
University of California at Santa Cruz conducted more 
68 
than 2,000 miles of aerial and boat surveys, which 
resulted in 58 sightings involving an estimated 110 
individuals. Further attempts to census the vaquita 
population have been even less successful. On 11-14 
September 1991 researchers from the National Marine 
Fisheries Service’s Southwest Fisheries Science 
Center, in cooperation with the Instituto Nacional de 
Pesca, La Paz, Mexico, conducted an experimental 
aerial census for the vaquita. The survey covered 709 
miles in 314 days and produced only one sighting of 
two vaquitas. 
Given this paucity of data, a systematically based 
population estimate of the vaquita is not available. 
However, considering the low sighting rate relative to 
survey effort, the few individuals seen per sighting, 
and the very limited geographic range of the species, 
there is little doubt that the population is extremely 
small, perhaps numbering in the low hundreds. 
The greatest direct threat to the vaquita appears to 
be incidental catch in gillnets, especially large-mesh 
nets used in fisheries for totoaba (itself an endangered 
species of fish), sharks, and other finfish. A number 
of measures have been taken to protect both the 
vaquita and the totoaba. Both are listed on Appendix 
I of the Convention on International Trade in Endan- 
gered Species of Fauna and Flora (CITES), the 
totoaba being added in 1977 and the vaquita in 1979. 
In 1978 the Government of Mexico designated the 
vaquita as rare and in danger of extinction, and the 
International Union for the Conservation of Nature 
and Natural Resources (now IUCN-The World Con- 
servation Union) listed the species as vulnerable in its 
Red Data Book. In 1979 the National Marine Fisher- 
ies Service listed the totoaba as endangered under the 
U.S. Endangered Species Act, and in 1985, following 
a recommendation of the Marine Mammal Commis- 
sion, the vaquita received the same designation. In 
1991, IUCN recognized the increasing gravity of the 
species’ condition by changing the vaquita’s status in 
its Red Data Book from vulnerable to endangered. 
As noted in previous annual reports, the Com- 
mission has encouraged and assisted in vaquita re- 
search and conservation efforts. In 1976 and again in 
1979 the Commission provided funding for surveys to 
determine the distribution of the species (see Appen- 
dix B, Wells et al. 1981 and Appendix C, Villa-R. 
