Informe Anual de la Comisión Interamericana del Atún Tropical, 19

ANNUAL REPORT 1987
Tuna vessels fishing in the EPa occasionally fish in other areas in the same year. In 1987 sorne
vessels which were part of the EPa fleet also fished in the western Pacific or in the Atlantic and
Caribbean. The 1980-1986 average catch by these vessels in the western Pacific was about 23
thousand tons (range: 6 to 84 thousand tons), and in the Atlantic and Caribbean about 11 thousand
tons (3 to 17 thousand tons). The maximum catches in these areas by vessels ofthe EPa fleet were
made in 1983, the year of the lowest total catch in the EPa (181 thousand tons) since 1961.
Preliminary estimates indicate that the 1987 total catches in these areas by vessels ofthe EPa fleet
were about 6 thousand tons in the western Pacific and 6 thousand tons in the Atlantic and
Caribbean.
The 1986 and preliminary 1987 catches by flag, and landings by country, oftunas in the CYRA
and the EPO are given in Tables 2-5. The landings are fish unloaded during a calendar year,
regardless ofthe year of catch. The country oflanding is that in which the fish were unloaded from
the fishing vessel or, in the case oftransshipments, the country which received the transshipped fish.
Beginning in 1984 the owners ofU.S.-flag vessels began chartering their services to companies in
Ecuador and Venezuela. The 1986 catches of US.-flag vessels inelude the catches of three vessels
under charter to a Venezuelan company, and those for 1987 inelude the catches of one vessel under
charter to a Venezuelan company.
Yellowfin was by far the most important component ofthe total harvest in both 1986 and 1987,
making up about 80 percent ofthe total catch ofaH species in the EPa in both years. Ofthe total 1986
EPa yellowfin catch of 296 thousand tons, 86 percent was harvested in the CYRA. In that year
Mexican-flag vessels took about 41 percent of the CYRA catch of yellowfin, followed by U.S.-flag
vessels wíth 28 percent; of the outside catch, US.-and Mexican-flag vessels harvested 69 and 31
percent, respectively. In 1987 91 percent ofthe catch of305 thousand tons was made in the CYRA. In
that year Mexican-and U.S.-flag vessels each took about 35 percent ofthe CYRA catch; ofthe outside
catch, U.S.-and Mexican-flag vessels harvested 52 and 43 percent, respectively. Together they
accounted for about 72 percent of the total EPa catch of yellowfin; they were followed by Venezuela
wíth about 14 percent and Ecuador with about 6 percent ofthe EPa yellowfin catch.
The tunas caught in the EPO in 1986 and 1987 were landed primarily in Ecuador, Mexico, and
the United States, wíth these three nations accounting for about 75 percent ofthe landed fish in 1986
and about 83 percent in 1987.
During the 1982-1986 period about 62 percent of the logged EPa catch of yellowfin has been
taken between 5°N and WN (Tables 6 and 7). Preliminary estimates for 1987 show that about 70
percent of the yellowfin catch was taken in this region. The distribution of the logged purse-seine
catch ofyellowfin in the eastern Pacific is shown in Figure 2. For skipjack, waters south oflOoN have
provided about 76 percent of the logged catch during the 1982-1986 period, with about 17 percent
being harvested south of the equator (Tables 6 and 7). Preliminary estimates for 1987 show that
about 80 percent ofthe total EPO logged skipjack harvest was made south oflOoN, but only about 10
percent ofthis was made south of the equator (Tables 6and 7). The distribution of the logged purseseine
catch of skipjack in the eastern Pacific is shown in Figure 3.
Under the terms of the convention which established the Inter-American Tropical Tuna
Commission, monitoring ofthe condition ofthe stocks oftunas and other species taken in the eastern
Pacific Ocean by tuna fisheries is the primary objective of the Commission's research. Taking into
consideration the migrations of the tunas, the mobility of the vessels of the tuna fleets of various
nations, and the international nature of the tuna trade, statistics on the catch and effort from the
eastern Pacific must be viewed in the light of global statistics. The IATTC staff routinely estimates
the global catches of the tunas and related species. The methodology of obtaining the estimates is
described in IATTC Internal Report 11. The estimated global catches oftunas and related species for
1986, the most recent year for which data are available, are presented in Figures 4 and 5. An
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