MARINE MAMMAL COMMISSION — Annual Report for 1992 
enactment of the International Dolphin Conservation 
Act of 1992, have focused on ways to eliminate rather 
than merely reduce incidental dolphin mortality. 
The 1992 Tuna Fishing Season 
In 1980 the National Marine Fisheries Service 
promulgated final regulations establishing annual 
quotas for individual dolphin stocks and a total annual 
allowable take for U.S. fishermen of 20,500 dolphins 
for the years 1981-1985. A general permit to take 
dolphins in compliance with those regulations was 
issued in 1980 to the American Tunaboat Association. 
In 1984 the Marine Mammal Protection Act was 
amended to extend indefinitely the annual quotas, the 
regulations, and the general permit and to add quotas 
for eastern spinner and coastal spotted dolphins. The 
terms of the general permit were further modified by 
amendments to the Marine Mammal Protection Act in 
1988 and 1992. For 1992 total dolphin mortality by 
the U.S. fleet may not exceed 1,000 animals. In 
addition, the International Dolphin Conservation Act 
enacted on 26 October 1992 prohibited U.S. vessels 
from setting on any school in which an eastern 
spinner dolphin or coastal spotted dolphin is observed 
prior to release of the net skiff. 
Estimates of the annual incidental kill of dolphins 
by the U.S. and foreign tuna purse seine fleets in the 
eastern tropical Pacific since passage of the Marine 
Mammal Protection Act are provided in Table 8. 
Although these are the best available mortality esti- 
mates, it should be recognized that the earlier esti- 
mates may not be accurate. Substantial observer 
coverage of the U.S fleet did not begin until 1976 and 
coverage remained below 50 percent until 1987. 
There were very few observers in the non-U.S. fleet 
prior to 1986, when observer coverage was approxi- 
mately 25 percent. While there are anecdotal reports 
of marine mammals sets being made to catch tuna in 
areas other than the eastern tropical Pacific Ocean, the 
frequency of these sets is believed to be low. No data 
on the level of marine mammal mortality that results 
from these sets are available. 
More detailed data for the last five fishing seasons 
are provided in Table 9. In addition to annual dolphin 
mortality data, information on mortality rates, fishing 
Table 8. _ Estimated incidental kill of dolphins in 
the tuna purse seine fishery in the 
eastern tropical Pacific Ocean, 1972- 
1992' 
Year U.S. Vessels Non-U.S. Vessels 
1972 368,600 55,078 
1973 206,697 58,276 
1974 147,437 27,245 
1975 166,645 27,812 
1976 108,740 19,482 
1977 25,452 25,901 
1978 19,366 11,147 
1979 17,938 3,488 
1980 15,305 16,665 
1981 18,780 17,199 
1982 23,267 5,837 
1983 8,513 4,980 
1984 17.732 22,980 
1985 19,205 39,642 
1986 20,692 112,482 
1987 13,992 85,185 
1988 19,712 59,215 
1989 12,643 84,336 
1990 5,083 47,448 
1991 1002 26,290 
1992 439 _ 
1 These estimates, based on kill per set and fishing effort data, 
are provided by the National Marine Fisheries Service and the 
Inter-American Tropical Tuna Commission. They do not 
include deaths of seriously injured animals released alive. 
effort, and observer coverage are presented. Com- 
plete 1992 data for non-U.S. vessels are not yet 
available, but where possible, estimates based on 
partial-year data are provided. 
The U.S. fleet continued to improve its perfor- 
mance in 1992. Although the fleet made a third more 
dolphin sets than it had in 1991, dolphin mortality was 
more than halved in 1992. A contributing factor was 
a marked reduction in the number of “problem sets,” 
those sets in which large numbers of dolphins are 
killed. Of 582 dolphin sets conducted by U.S. fisher- 
men in 1992, only four resulted in the deaths of 15 or 
more dolphins. About 85 percent of the sets resulted 
in no incidental mortality. 
