Volumen 44 - Número 2 - 369-377

Volumen 44 - Número 2: 369-377 \| 2009 Article	PDF
Invertebrate bycatch in Patagonian scallop fishing grounds: a study case with data obtained by the On Board Observers Program
Mariana Escolar^1,2*, Mariano Diez^2,3, Daniel Hernández¹, Ángel Marecos^1,2, Silvana Campodónico¹ and Claudia Bremec^1,2
¹Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), V.Ocampo 1, B7602HSA Mar del Plata, Argentina ²Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Rivadavia 1917, C1033AAJ Buenos Aires, Argentina ³Centro Austral de Investigaciones Científicas (CADIC-CONICET), Houssay 200, V9410CAB Ushuaia, Argentina *This email address is being protected from spambots. You need JavaScript enabled to view it.
Since the beginning of the Patagonian scallop fishery Zygochlamys patagonica, in the Argentine Sea in 1996, an On-Board Observers Program (OBOP) was established at the National Institute of Fishery Research and Development (INIDEP). The general trends of the bycatch composition and biomass were analysed from information on catches and fishing effort (219 trips, 575 samples), collected in five scallop beds between 39º and 44º S during the period 1997-2002, provided by the OBOP. Large variations in average density of bycatch and the presence of eight taxonomic groups were determined during the study period. Echinodermata was the dominant taxon in most of the scallop beds. Echinoderms and gastropods showed an increase in biomass and sessile organisms were scarce in the SWSAO bed, subjected to high and continuous fishing effort. In the SWTB bed, with the lowest fishing effort, sessile organisms showed a decrease during the study period, while no variations occurred in the case of echinoderms and gastropods. The mentioned groups, mainly scavengers and predators, would be favoured by fishing activity that increased food availability (discards and damaged organisms). Contrarily, potential settlement substrates as sessile organisms, decreased in areas with intensive fishing activities. We stress out the validity of this source of data, which widens the spatio-temporal coverage of the yearly stock assessment cruises and is optimal for producing long-term databases.
Key words: Argentine Sea, fishing effort, non-target species, scallop fishery, Zygochlamys patagonica
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