Biological parameters of franciscana dolphins, Pontoporia blainvillei, bycaught in artisanal fisheries off southern Buenos Aires, Argentina.

NEGRI, M. F.; PANEBIANCO, M. V.; DENUNCIO, P.; PASO VIOLA, M. N.; RODRÍGUEZ, D.; CAPPOZZO, H. L.

JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2014

0025-3154

The franciscana dolphin (Pontoporia blainvillei) isa small coastal dolphin endemic to the Southwestern Atlantic Ocean. Incidental captures infishing gillnets is possibly the greatest conservation concern for this species and occurs within most of its geographical distribution. The aim of this paper was to determine the biological parameters of franciscana dolphin bycaught from artisanal coastal fisheries of the southern Buenos Aires province, Argentina. Between 2003 and 2009, carcasses of 54 incidentally captured franciscanas were collected. The age, sexual and physical maturity, and body condition of each specimen was determined. Thesex ratio of the bycaught dolphins did not differ from parity and, consistent with other areas, juveniles younger than 4 years old were captured in higher proportion (69%). In addition, 74% of the entangled animals were sexually immature and the 85% physically immature. Sexually immature dolphins were predominant in the spring, a period that coincides with the breeding season. An assessment of the body condition of captured franciscanas suggested that entanglements were not associated with a disease or physiological disorder. The results presented here are important to assess the impact of artisanal fisheries on the population of franciscana dolphins in the southernmost area of its distribution.