Spatio-temporal variability in mortality rates of White-chinned Petrels Procellaria aequinoctialis interacting with longliners fishing in the South-west Atlantic

GÓMEZ LAICH A & M FAVERO

BIRD CONSERVATION INTERNATIONAL

Bird Conservation International

Lugar: Londres; Año: 2007 vol. 17 p. 359 - 366

0959-2709

The White-chinned Petrel Procellaria aequinoctialis is the second most commonly captured species by Argentinean longliners. The severe declines that this species has experienced in some of its populations have been principally attributed to the incidental mortality associated with longliners. In this study we analyse the spatio-temporal variability in the mortality rates of White-chinned Petrels in the Patagonian Shelf and the effect that environmental and operational variability have on such mortality. The average capture rate (± one s.d) for the period 1999-2003 was 0.014 ± 0.090 White-chinned Petrels every 1,000 hooks deployed. Higher capture rates were observed during the austral autumn and winter seasons and particularly when short longlines were deployed. The distribution of the captures differed throughout the year. During autumn-winter most captures took place in the north of the Patagonian shelf, whereas during spring-summer, incidental captures occurred principally to the South between 45ºS and 50ºS.