MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
Bycatch of franciscana dolphins Pontoporia blainvillei and artisanal fisheries dynamics in the species southernmost distribution
NEGRI, M. F.; DENUNCIO, P; PANEBIANCO, M. V.; CAPPOZZO, H. L.
BRAZILIAN JOURNAL OF OCEANOGRAPHY
Lugar: São Paulo; Año: 2012 vol. 6 p. 151 - 151
In Argentina, the franciscana dolphin is one of themost vulnerable cetaceans regularly entangled in coastal artisanal fishery nets. The aim of this paper is to estimate the species´ incidental mortality on the Southern coast of Buenos Aires province throughinterviews with the captains of artisanal fishing vessels, in the period 2006-2009. Franciscana bycatch was reported for gillnets and shrimper gear all year round but it occurred more frequently between October and February, at 5 km offshore and 10-20 m depth. The estimated mean annual incidental mortality was 107 dolphins (CI 95% = 87-129), 92 caught in gillnets (CI 95% = 73-112) and 15 in shrimpers´ gear (CI 95% = 8-25) with a capture per unit effort of 0.029 dolphins per km of gillnet (CI95% = 0.023-0.036) and 0.022 per shrimper´s net (CI 95% = 0.012-0.035). Annual fluctuations were due to differences in the number of gillnetting fishing days. If mortality estimates for the Northern coast are also taken into account, values attaina maximum of 360-539 dolphins bycaught in the entire Buenos Aires province, representing 2.5-3.7% of the species´ abundance in Argentina. This will inevitably lead to the decline of franciscana dolphin populations in the near future unless alternative fishing grounds are identified and alternative gearadopted.