Biological parameters of franciscana dolphins, Pontoporia blainvillei, by-caught in artisanal fisheries off southern Buenos Aires, Argentina

NEGRI MARIA FERNANDA; PANEBIANCO MARIA VICTORIA; DENUNCIO PABLO; PASO VIOLA MARÍA NATALIA; RODRÍGUEZ DIEGO; CAPPOZZO HUMBERTO LUIS

JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2014

0025-3154

The franciscana dolphin (Pontoporia blainvillei) is a small coastal dolphin endemic to the south-western Atlantic Ocean.Incidental captures in fishing gillnets is possibly the greatest conservation concern for this species, and occurs within mostof its geographical distribution. The aim of this paper is to determine the biological parameters of franciscana dolphinby-caught from artisanal coastal fisheries of the southern Buenos Aires province, Argentina. Between 2003 and 2009, carcassesof 54 incidentally captured franciscanas were collected. The age, sexual and physical maturity and body condition of eachspecimen was determined. The sex-ratio of the by-caught dolphins did not differ from parity and, consistent with otherareas, juveniles younger than 4 yr old were captured in higher proportion (69%). In addition, 74% of the entangledanimals were sexually immature and 85% physically immature. Sexually immature dolphins were predominant in thespring, a period which coincides with the breeding season. An assessment of the body condition of captured franciscanas suggeststhat entanglements were not associated with a disease or physiological disorder. The results presented here are importantto assess the impact of artisanal fisheries on the population of franciscana dolphins in the southernmost area of itsdistribution.