Tropical Tunas Working Group Recife April 2007 Main
- Slides: 10
Tropical Tunas Working Group Recife, April 2007
Main topics studied • Update of basic statistics, CAS and tagging database • Estimation of landings that are directed out of the canning factories (“faux-poisson”) • Review of new biological information and fishery indicators for YFT, BET and SKJ • Indicators relevant to multi-species fisheries and ecosystems • Recommendations
Statistics • Task 1 and 2: revisions following the work done in Sète (2006) • Sizes: update and building of the CAS for YFT and SKJ • Tagging: progress on improving the tropical tunas databases; still work to be done for YFT and SKJ by Secretariat and scientists • Preparation of BET assessment: revision of the “fisheries” definition and data preparation for Multifan-CL analysis
200 40% 150 30% 100 20% 50 10% 0 0% 1980 1985 Faux-poisson 1990 1995 Commercial tuna 2000 2005 % Faux-poisson % Catch ('000 tons) « Faux-poisson » 1 - Total amount landed in Abidjan
« Faux poisson » 2 - Quantities according to the fleet
« Faux poisson » 3 - Species composition 1997 -1998 sampling 2004 -2005 sampling Others 16% Others 14% Skipjack 13% Minor tunas 65% Skipjack 42% Yellowfin and bigeye 8% Minor tunas 28% Yellowfin and bigeye 14%
« Faux poisson » 4 - Size composition Major Tunas Minor Tunas 1000 2000 YFT - mean LF 39, 8 (1, 2 kg) AUX - Mean LF 38, 7 (1, 1 kg) SKJ - mean LF 39, 2 (1, 1 kg) LTA - Mean LF 45, 6 (1, 5 kg) BET - Mean LF 39, 3 (1, 3 kg) 750 1500 1000 250 500 0 0 20 25 30 35 40 45 50 55 60 65 70
« Faux poisson » 5 - Conclusion • These landings are quite important and should be taken in account for assessments • Ways to avoid risks of double counting of catches (transshipments, observers) have to be axamined • Studies to better estimate the species composition by fleet should be continued • The way to take them in account in the statistics has still to be defined (discards, new category? )
