Résumé
The South West Indian Ocean Fisheries Project (SWIOFP) was formally launched in June 2008, and the first year of the project was used to compile and assess existing fisheries information to provide a baseline for long-term planning of projects. The activities of Component 4 (Pelagic fishes) took place at 3 levels - national data gapanalyses by 9 countries, followed by integration into a regional analysis, and finally, prioritization of species, key issues and planning of future projects at a regional Component 4 workshop held at the Seychelles Fishing Authority (SFA) on 10th - 12th August 2009. The national gap-analyses showed that few datasets on pelagic fishes and fisheries exist locally, and that datasets are scattered among government and/or private institutions, are of questionable quality, and are kept in a variety of formats. The region lacks robust datacollection and data-management systems, or the means and expertise to achieve effective and consolidated systems. There is a scarcity of studies / information on most of the prioritized species, in nearly all SWIOFP countries. Few scientifically defendable management strategies (national or regional) exist. Several of the target or bycatch species of the region have high commercial value and are heavily fished by foreign fleets, and on a more localized coastal scale by artisanal fishers. Some species/or species groups are now considered to be vulnerable. The regional gap-analysis showed that a significant amount of data-collection and research have been done on large pelagic fishes in the region, through French initiatives, and under the jurisdiction of the Indian Ocean Tuna Commission (IOTC). Furthermore, acoustic and midwater trawl information on small pelagic fishes exist for several of the shelf areas (i.e. Kenya, Tanzania, Mozambique, Madagascar) from past and recent surveys by research vessels (i.e., the R/V Dr. Fridtjof Nansen). A list of 81 pelagic fish species were selected and prioritized into 4 information categories with increasing data collection requirements (i.e. level 1 = presence/absence; 2 = size composition; 3 = biological information incl. otoliths; 4 = genetic samples / migrations). New data in these 4 categories need to be collected by port samplers, fisheries observers, and during dedicated surveys using wet-leased vessels or research ships. In the category for large pelagic fishes, 4 oceanic shark species (Carcharhinus falciformes, C. longimanus, Prionace glauca and Isurus oxyrhinchus) were prioritized at information level 4, reflecting their uncertain stock status and importance as target- and bycatch species in long-line fisheries. Swordfish (Xiphias gladius) was prioritized at level 4, pending archival pop-up and sonic tag studies on vertical and horizontal movements, and the other billfishes were all prioritized at level 3. Bigeye tuna (Thunnus obesus) and skipjack tuna (Katsowonus pelamis) were also prioritized at level 4. Projects on these species should aim to incrementally strengthen IOTC assessments.