INVESTIGADORES
CAPPOZZO Humberto Luis
artículos
Título:
Incidental mortality of franciscana dolphin (Pontoporia blainvillei) in Argentina
Autor/es:
CAPPOZZO, H.L.; NEGRI, M.F.; PEREZ, F. H.; ALBAREDA, D.; MONZON, F; CORCUERA, J.
Revista:
THE LATIN AMERICAN JOURNAL OF AQUATIC MAMMALS
Editorial:
SOLAMAC
Referencias:
Año: 2007 vol. 6 p. 127 - 133
ISSN:
2236-1057
Resumen:
La Plata River dolphin or franciscana, Pontoporia blainvillei, is
an endemic small cetacean of the Southwest Atlantic coast. It is
threatened all along its distribution by a sustained high level of
incidental mortality in fisheries. Here we assess levels of franciscana
bycatch in Argentine waters between 1997 and 2003. We surveyed 18
localities along the coast of the Buenos Aires Province, between General
Lavalle (35°06'S, 57°08'W) and Bahía Blanca (Puerto Rosales-Ingeniero
White harbour: 38°47'S, 62°16'W). We recorded data on incidental
mortality, fishing gears and fishing effort through 209 personal
interviews with fishermen. We estimated annual mortality, fishing effort
and catch per unit of effort (CPUE) for each locality and period of
time. Mortality was caused by gillnets and trawling gears, purse seine
nets and shrimper gears. The total mortality estimated for 1997-2000 was
354 dolphins/year (95% CI = 318-392) and 307 dolphins/year (95% CI =
273-343) for 2002-2003. In the entire survey, CPUE of the northern coast
of Buenos Aires Province (Bahía Samborombón and Cabo San Antonio) was
significantly higher than CPUE for the southern coast (from Mar del
Plata to Bahía Blanca estuary). In addition, CPUE of the northern coast
decreased significantly throughout the years. This study suggested that
even though the gears or fleet behavior changed locally, Buenos Aires
Province evidenced an overall mortality relatively constant during the
survey. If we consider a minimum of 400 dolphins killed each year in
fishing gear and the estimated population values of 15000 individuals
for the Argentine coast; mortality represent more than 2% of the
Argentine franciscana population, suggesting that it would be subject to
decline. Trends in mortality need to be periodically monitored in this
area in order to articulate programs of conservation for the species.