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Cephalopods in the Trawl Fisheries in the Southeastern Brazil (1979-2000)

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Cephalopods in the Trawl Fisheries in the Southeastern Brazil (1979-2000) ICES CM 2004: CC 26 Cephalopod Stocks: Review, Analysis, Assessment, and Sustainable Management Cephalopods in the trawl fisheries in the southeastern Brazil (1979-2000) Tomás, A.R.G.; Gasalla, M.A.; Loyo, B.G.; Marques, C.A. Centro APTA do Pescado Marinho / Instituto de Pesca / SAA-SP Av. Bartolomeu de Gusmão 192, Santos, SP, Brasil, 11030-906 www.pesca.sp.gov.br E-mail: [email protected] Introduction The interest over cephalopods fisheries in southeastern Brazil increased after the middles of 80´s when a crisis in shrimp trawl catches forced the fleet to find in the bycatch an aid to reduce operation costs, driving fishery effort to seasonal targets, including squids and octopus. This study evaluates the importance of the cephalopods exploited by trawl fisheries of the southeastern Brazil (23o to 27oS) composed by shrimps and fishes double-rigger trawlers. Figure 1 Trawl fishing area of southeastern Brazil Methodology considered in this contribution (RJ: Rio Data were provided by statistical database from ‘Instituto de Janeiro; SP: São de Pesca’ (a scientific governmental organization of São Paulo Paulo; PR: Paraná States). State) and samples obtained during the landings in the fisheries wharves in Santos and Guarujá cities between January 1993 and December 2000. Additional landing data from Rio de Janeiro and Santa Catarina States fleets were also collected. For general purposes, southeastern Brazil was considered the region between 23o S to 29o S, covering coasts of Rio de Janeiro, São Paulo, Paraná and Santa Catarina States (Figure 1). Table I List of cephalopod species registered and their importance in the trawl fisheries of Fishing Characteristics southeastern Brazil (1979-2000) The bottom trawl fleet of Southeastern Brazil consists on 15 to 23 m wooden and steel 115 to 380 HP powered boats, which majority acts as double-outrigger aimed to the pink Species Fishery importance shrimp (Farfantepeneus) species (Perez et al., 2001; Tomás et Loligo plei High al., 2003) (Figure 2). Loligo sanpaulensis High Lolinguncula brevis None Those boats often operate along the whole day in 4 to 6 Illex argentinus Low (higher southwards) hr hauls mainly between 30 to 130 m over muddy and sand Ommastrephes bartrami Low flats in 10 to 15 days-trip (freezer boats over 30 days-trip). Pickfordiateuthis pulchella None Earlier works (Graça-Lopes et al., 2002) registered 276 Semirossia tenera None Octopus cf. vulgaris High taxa occurring as bycatch of this fisheries. Octopus tehuelchus Medium Figure 2 Octopus defillipi None Typical boats from bottom trawl fisheries fleet Eledone massyae Medium of southeastern Brazil. Eledone gaucha Low Scaergus unicirrhus Medium Results Tremoctopus violaceus None Loliginid squid was the best cephalopod category represented (68% in average through the period, varying from 39 to 85%) with two species: common squids Loligo plei and Loligo sanpaulensis. The Argentinean calamar Illex argentinus occurred when boats operations were done 2500 deeper than 100 m during austral winter. Octopus Among the octopuses (32% of all cephalopods, varying 2000 Squid from 15 to 61%), the common octopus Octopus cf. vulgaris ) t represented almost the entire catches (90%), followed by the ( 1500 combed octopus Eledone massyae. Others species were ngs 1000 registered in the landings in small numbers (Table I). ndi La The characteristic behaviour of variable inter-annual 500 Figure 3 cephalopod biomass may be shown through graphic analysis Evolution of the cephalopods (Figure 3). 0 catches in the southeastern Brazil 3 9 through the studied period. 79 81 83 85 87 89 91 9 95 97 9 The species composition in the area do not differ, but 19 19 19 19 19 19 19 19 19 19 19 abundance shown local differences possibly due to the oceanographic conditions, as a seasonal upwelling around 23oS amplifying the catches of E. massyae and L. sanpaulensis. References: Some annual yield peaks registered along the studied Graça-Lopes, R. da; A.R.G. Tomás; S.L.S. Tutui, E. Severino-Rodrigues, A. Puzzi. 2002. Fauna Acompanhante da Pe period may be related to earlier favourable conditions to no Litoral do Estado de São Paulo, Brasil. Boletim do instituto de Pesca, S.Paulo, 28(2): 173-188 (in Portuguese). recruitment, maybe related to ENSO (El Niño-Southern Tomás, A.R.G., M.A. Gasalla; M.H. Carneiro. 2003. Dinâmica da Frota de Arrasto de Portas do Estado de São Paulo. Oscillation) Phenomena. Rossi-Wongtschowski, C.L.D.B. (coords.) Dinâmica das Frotas Pesqueiras - Análise das Principais Pescarias Com Sudeste-Sul do Brasil, Programa Revizee / Score Sul, MMA e CIRM, Ed. Evoluir, São Paulo: 39-64 (in Portuguese Those characteristics positioned the cephalopods not more as accessories catches, but as important fisheries resources with potential market to be explore, not only driven to the domestic market. .
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