E - Iccat

ICCAT REPORT 2012-2013 (I)
Some catch statistics are uncertain, i.e., significant catches of bigeye, yellowfin and skipjack, as well as other
species are landed in West Africa and sold as faux poisson. Monitoring should be improved as important catches
might not be reported (faux poisson). This also concerns the bigeye catches taken by purse seiners (estimated
from Japan’s import statistics), as these estimations are uncertain. The estimates of unreported catches of some
purse seiners are very important. They have increased since 2006 and could exceed 20,000 t per year for the
three major species.
As regards the “faux poisson” landed at the Abidjan market, the average is 6,641 t from 1998 to 2007. The
Committee includes these estimates in the reported historical catches of EU-purse seiners since 1981, as well as
in the catch-at-size matrices. However, new estimates indicate record levels amounting to around 11,000 t per
year between 2005 and 2010 for the overall purse seine fleets operating in the East Atlantic.
The catches of one purse seiner component of the fleet transhipped at sea before 2011 were excluded from the
processing of the fishing statistics. The unreported catches of a part of the fleet provide detailed information.
However, an important part of some purse seiners was evaluated by comparing the landings in West African
ports and the data from the canneries reported to ICCAT. Estimates of these unreported catches have increased
and the Committee has expressed the need for the countries and the industries concerned to improve the
collection of the data. The preliminary results of the recent mission of experts in Ghana, under the auspices of
ICCAT, suggest the existence of bias in the sampling protocol aimed at correcting the multi-species composition
of the catches recorded in logbooks. This process is still on-going. The estimates have not been incorporated in
the assessments and are not included in the estimates of reported catches. However, their magnitude is likely to
influence the assessment of the state of the stock.
There are also some uncertainties in the biological parameters: natural mortality, growth, stock structure and
movements. A tagging program should be encouraged to resolve these uncertainties by providing comparative
biological results, movement patterns and a possible stock structure, as well as an analysis of interactions
between fleets, data on the effects of FADs on tuna resources, an assessment of the management measures (i.e.:
the effect of the closures). Tagging programmes that are carried out correctly provide useful information to
respond to the most important question: the size of the population.
Dr. Santiago noted that Dr. Alain Fonteneau (European Union) gave a presentation at midday on November 14
describing results from the IOTC tagging program in the Indian Ocean and the need for a similar program in the
Atlantic Ocean.
The Atlantic provides 6% of the worldwide production of skipjack tuna (last assessment carried out in 2008).
These catches are carried out mainly by purse seiners and baitboats. Catches in 2011 were very high both in the
East and West Atlantic: 173,338 t, i.e. an average 34% increase compared to the 2006-2010 average. It is
unlikely that the eastern stock is overexploited and in the West Atlantic the catches are higher than the current
replacement yield.
There is no specific recommendation in force for skipjack tuna. Although average catches in recent years are
below the MSY, the Committee is concerned about the high level of catches in 2011 on both sides of the Atlantic
and the recent potential underreporting in the East Atlantic. Recommendation 11-01, which will enter into force
in 2013, should have an impact on skipjack catches. The SCRS estimates that catches should not exceed the
MSY. The Commission should be aware that the increase of skipjack catches and fishing effort could have
involuntary consequences on other species caught in association with skipjack in some fisheries.
For bigeye tuna (last assessment conducted in 2010), 18% of the worldwide production is taken from the
Atlantic. Catches carried out by purse seiners, baitboats and longliners reached 77,000 t in 2011 (the average
catches for 2006-2010 amounted to 75,000 t). The historical peak of 1994 reached 133,000 t followed by
declines in catch related to the reduction in fishing fleet size (longliners), as well as the decrease in fishing effort
(longliners and baitboats). The number of active purse seiners declined by more than half from 1994 to 2006, yet
experienced an increase since 2007 (piracy in the Indian Ocean and the presence of other fleets).
The average weight of bigeye tuna caught in free schools is significantly higher than bigeye tuna caught under
FADs, and these differences are more marked throughout the last four years.
There is considerable uncertainty as regards the stock status and the projections for bigeye tuna. 52% of model
outcomes considering uncertainties indicated that bigeye tuna stock status in 2009 was consistent with the
Convention objectives. The 2011 catches of bigeye tuna (77,513 t) are less than the corresponding TAC.
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