INVESTIGADORES
MARIANO Y JELICICH Rocio
congresos y reuniones científicas
Título:
Black-browed Albatrosses and Longliners: Intrinsic and Extrinsic Variability affecting the Mortality along the Patagonian Shelf
Autor/es:
FAVERO, MARCO; GÓMEZ LAICH, AGUSTINA; MARIANO Y JELICICH, ROCÍO; BLANCO, GABRIEL; ARIAS, ALEJANDRO; SILVA RODRÍGUEZ, MARÍA PATRICIA; BRACHETTA, HUGO; CAÑETE, GUILLERMO
Lugar:
Montevideo
Reunión:
Congreso; III International Albatross and Petrels Conference; 2004
Resumen:
Population decreases of Black-browed Albatrosses (BBA)
breeding in islands of the South-western Atlantic Ocean
have been partially attributed to the mortality of birds while interacting with
longline fishing vessels. Reductions of about 20% of the populations in
Malvinas (Falkland) Islands were reported for the period 1995 2000 (N Huin pers. comm). Studies on the mortality of seabirds
along the Patagonian shelf and shelf break from 1999 to 2001 indicated by-catch
rates of 0.04 0.30 birds/1,000± 0.40
birds/1,000 hooks, with a maximum of 0.20 ± hooks (Favero et al.
2003). Around 10,000 albatrosses and petrels were killed by longliners through
this three-year period. Most captures were observed near the edge of the continental
shelf or on the shelf break, between 37ºS and 48ºS, where most of the fishing
effort was concentrated. Most of the birds killed were BBA (more than 55% of
total captures) and White-chinned Petrels (WCP, 20% of captures). BBA were
mainly caught when lines were deployed under low or intermediate wind
intensities. A positive relationship between by-catch rates and luminosity
during the night setting was observed, with higher rates observed during full
moon nights. The captures registered during the fall-winter (i.e. interbreeding
season) were widely distributed to the North of the shelf break, while those
observed during spring-summer were mostly concentrated in the southernmost
latitudes, closer to the presumed breeding area in Malvinas. While mortalities
during winter were mainly associated to the Patagonian toothfish fishery, those
observed during summer were associated with longliners targeting on kingklip in
the Patagonian Shelf.