TUNA FISHERIES CATCH LANDED IN ABIDJAN (CÔTE D IVOIRE) AND SOLD ON LOCAL FISH MARKET FOR THE PERIOD - PDF

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SCRS/215/72 Collect. Vol. Sci. Pap. ICCAT, 72(3): (216) TUNA FISHERIES CATCH LANDED IN ABIDJAN (CÔTE D IVOIRE) AND SOLD ON LOCAL FISH MARKET FOR THE PERIOD Chavance 1 P., Dewals 1 P., Amande

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SCRS/215/72 Collect. Vol. Sci. Pap. ICCAT, 72(3): (216) TUNA FISHERIES CATCH LANDED IN ABIDJAN (CÔTE D IVOIRE) AND SOLD ON LOCAL FISH MARKET FOR THE PERIOD Chavance 1 P., Dewals 1 P., Amande 2 M. J., Delgado de Molina 3 A., Cauquil 1 P., Irié 2 D. SUMMARY This note presents data collected (quantities by type of vessels and flags, species composition, size structure) since 1982 on catches landed by tuna fisheries in Abidjan and sold on local market. RÉSUMÉ Cette note présente les données recueillies (quantités par type de navires et pavillons, composition par espèce, structure des tailles) depuis 1982 concernant les prises débarquées par les pêcheries de thonidés à Abidjan et vendues sur le marché local. RESUMEN Este documento facilita los datos recopilados (cantidades por tipo de buque y pabellón, composición por especies y estructura de tallas) desde 1982 para las capturas desembarcadas por las pesquerías de túnidos en Abiyán y comercializadas en el mercado local. KEYWORDS Local market, data collection, by catch, tuna fisheries, purse seining 1. Introduction This document presents data on fish landed by tuna fisheries and sold to the local market in Abidjan from 1982 to 214. This fish are major tunas that are rejected by canneries, undersize and little tunas (skipjack, bullet tuna, yellowfin, bigeye, little tunny) and also appreciated species caught as by-catch like marlin, sailfish, wahoo, dolphinfish, barracuda, triggerfish and shark. Generally called Faux Poisson in French, because it was initially considered as the fish basket given to the fishermen at the end of the trip, this category of fish is now representing a significant component of the landing due to growing bycatch associated with DFAD fishing developpement and sharp local demand in Abidjan city. 2. Origin of data As indicated in Chavance et al. (21), monitoring the fish landed and sold through the local market, is by nature a very difficult task. Since the beginning, it has been considered unrealistic neither to collect formal data (formularies, invoices ) neither to estimate directly weights. It then has been preferred to evaluate the number of transports units associated with weight coefficient. For specimens (billfishes, sharks), numbering of heads are used in order to avoid double counting associated with a mean weight by types of specimen. Weight coefficients by transport units were fixed empirically periodically by observers and try to reflect changes occurring in transport practices. Since May 29, a weighbridge has been installed at the fishing port exit and generates exact weights of transport unit each one being inventoried and its specific net weight defined. All industrial vessels, in principle, are systematically monitored for their landings destined to local market whatever their nationality and their type (fishing or carrier vessels). These data were collected through a collaboration between France (IRD), Spain (IEO) and Côte d Ivoire (CRO). 1 Institut de Recherche pour le Développement (IRD), UMR 212 MARBEC, Sète, France patrice.dewals.ird.fr, 2 Centre de Recherches Océanologiques (CRO), Abiddjan, Côte d Ivoire 3 Instituto Espanol de Oceanograpfia (IEO), C. O. de Canarias, Santa Cruz de Tenerife, Spain 674 3. Computation Total estimates of landings are obtained by summing up the product of the numbering of transport units (vehicle, bags, pieces ) by their reference weights. When direct weights are available, they are also used. The precise origin of the product (vessels, type of boats, nationality, fleet and date of landings) is therefore known. composition before 25 has been estimated using species composition given by N Goran (2). Since 25 species composition of the landings destined to local market is done by dedicated port samplers that estimate visually the percentage of species for each vehicle. This species composition is applied for fish landed in bulk when available. Length measurements have been set in place in a regular manner since 27. They occur on board vessel (all type and all nationality) for samples around 2 individuals each and concerns uniquely tuna fish species (major and minor). Percentage of species composition of these samples may therefore also be used to estimate composition among tunas. Nationality of vessels are generally used to sum up landing by countries. For european countries, landings from vessels belonging to associated flags are also accounted for if information available. 4. Main results In the beginning of 8s landing of small sizes tunas and other non target species started in Abidjan following the developpment of fishing on floating object which is the main source of bycatch in purse seine fishery. These landings reach 43 tons in 214 and display interannual fluctuations and periods which can be summarized as follow: The growth period from 1986 to 1994, The european limitations set in place by fishing companies (1994-2), The political and security problems in Côte d Ivoire (21-22) The growth of landings by ghanaians carriers followed by guineans fishing vessels (24-214) 5. Structure of data set folder ABJ_LM_ xls LANDINGS: Annee (year) Mois (month) L_PAYS (Vessel flag) L_FLOTTE_2 (Fleet flag)* L_TYPE_B (Type of vessel) FAO Code_2 (FAO species code) POIDS (Quantities in tons) LENGTH annee (year) mois (month) L_PAYS (Vessel Flag) L_FLOTTE (Fleet flag)* L_TYP_B (Type of vessel) FAO Code_2 (FAO species code) V_LONG (Lower Fork Length size classe in cm) Nbre (Number measured) Poids_echant_kilo (Weigth in kg in samples) (*) see text for nationality use 675 References Chavance Pierre, Patrice Dewals, Monin Justin Amandè, Alicia Delgado de Molina, Alain Damiano, Athanase Tamegnon Tuna fisheries catch landed in Abidjan (Côte d Ivoire) and sold on local fish market for the period (preliminary data). Col. Vol. Sci. Pap. ICCAT, 71(1): Chavance Pierre, Alicia Delgado de Molina, Monin Justin Amandè, Laurent Floch, Patrice Dewals, Athanase Tamegnon Faux Poisson landed in Abidjan for the period Preliminary data. ICCAT Tropical Tuna species group intersessional meeting on the Ghanaian statistics analysis (Phase II), Madrid, May 3 - June 3, 211. Chavance Pierre, Jean Baptiste Amon Kothias, Patrice Dewals, Renaud Pianet, Monin-Justin Amandè, Alicia Delgado de Molina and Aude Djoh Statistics on tuna surface fishery s bycatch landed in Abidjan, Côte d Ivoire, for the period. Col. Vol. Sci. Pap. ICCAT, 66(5): N Goran Nestor. 2. Estimation des quantités de faux poisson débarquées au port d abidjan. Annexe (Document multigraphié). 676 Table 1. composition of fish product landed by Tuna fisheries in Abidjan as estimated by N Goran (2). FAO Code_2 prop SKJ.131 BET.21 YFT.62 TUX.65 BIL.24 TRI.13 SHX.4 PEL.95 Total Local Market Landings in Abidjan (corrected) 4 Quantities (t) 3 1 BET BIL PEL SHX SKJ TRI TUX WAH YFT ALB FRI LTA TUN Year Figure 1. Total fish landed by species groups by tuna fisheries in Abidjan (Côte d Ivoire) destined to local market. Catch composition before 25 is estimated from N Goran (2) and, after 25, by permanent monitoring. 3 Local Market in Abidjan by species and vessels types Carrier Pole and Line Purse seiner Quantities (t) BET BIL PEL SHX SKJ TRI TUX WAH YFT ALB FRI LTA TUN Year Figure 2. Total fish caught by species group and main vessel types landed by tuna fisheries in Abidjan (Côte d Ivoire) destined to local market. Catch composition before 25 is estimated from Ngoran (2) and, after 25, by permanent monitoring. 678 Local Market Landings in Abidjan by main flags 4 Quantities (t) 3 Flag Cambodge Espagne France Ghana Guinée Conakry OTH Year Figure 3. Total fish caught by main fishing countries (including associated flags for European countries) by tuna fisheries in Abidjan (Côte d Ivoire) and destined to local market. Size structure and species composition in Abidjan 3 Nbr individuals Auxis thazard Euthynnus alletteratus Katsuwonus pelamis Thunnus albacares Thunnus obesus LF cm Figure 4. Total size structure and species composition of fish landed in Abidjan (Côte d Ivoire) and destined to local market. 679 Figure 5. Size structure and species composition of fish landed by type of type of vessels in Abidjan (Côte d Ivoire) and destined to local market. Number of individuals sampled by species in Abidjan 6 4 Nbr individuals Auxis thazard Euthynnus alletteratus Katsuwonus pelamis Thunnus albacares Thunnus obesus Years Figure 6. Number of individuals measured by year and species in Abidjan (Côte d Ivoire) and destined to local market. 68
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