Interacciones entre aves marinas y la flota palangrera industrial orientada a la captura de pez espada en Chile. Paper presented for consideration at the Agreement on the Conservation of Albatrosses and Petrels, Fourth Meeting of the Seabird Bycatch Working Group Guayaquil, Ecuador, 22 – 24 August 2011.

Abstract

The interaction between seabirds and fishing operations has been i de n tified as the main cause for diminishing albatros and petrel populations ( Procellariiformes ) . In Chile, the industrial longline fishery targeting swordfish ( Xiphias gladius ) is currently monitoring seabird bycatch by trained onboard scientific observers. Fr om 2005 to 2010 a total of 232 seabirds were reported as bycatch in this fishery belonging to 14 species . In terms of frequency, the most important were: Black - browed Albatross (n=123), Wandering Albatross (n=30), Cape Hen (n=23), Grey - headed Albatross (n=15), Buller's Albatross (n= 12). The seabird by catch rate, measured as number of seabird caught per 1000 soaked hook s , indicated a maximum by catch rate of 0.07 in 2007 whereas in 2010 it decreased to 0.01. The swordfish’s fishery operate s throughout the year, howeve r, t he seabird byc atch is observed only between May and October which maximum is reached in September. A clear spatial distribution of seabird bycatch is also observed between Valparaiso (33 °S) and the North of Caldera (27°S). A number of m itigation measures have been impo sed by Chilean authorities , Plan de Acción Nacional - Aves Marinas (PAN - AM), where the most important are the use of Tori lines, fishing operation restricted only to night setting (one hour after the sunset and one hour before the sunrise) and a minimum lin e weight of 60 g. From a total of 814 fishing hauls observed in 2010 only the 5.14% o used tori line and the 28% of them were setting overnight , whereas the minimum weight line is always reached. Mitigation measures are compulsory although only a small pro portion of fishing hauls acomplished their requirements. Thus, a monitoring program must be enforced and fishing crew should be informed about the impor tance of seabird conservation

La interacción entre las aves marinas y las operaciones de pesca se ha identificado como la causa principal de la disminución de albatros y petreles (poblaciones Procellariiformes). En Chile,en la pesquería de pez espada a través de palangre industrial (Xiphias gladius) se monitorea la captura incidental de aves marinas a través de observadores científicos que van a bordo de las embarcaciones. De 2005 a 2010 se registraron un total de 232 aves marinas como captura incidental en esta pesquería perteneciente a 14 especies. En cuanto a la frecuencia, las más importantes fueron: Albatros Negro-cejudo (n = 123), Albatros Errante (n = 30), Cabo Hen (n = 23), de cabeza gris Albatross (n = 15), albatros de Buller (n = 12). La tasa de captura incidental de aves marinas, medida como el número de aves marinas capturado por 1000 empapado ganchos, indicó una tasa máxima de captura incidental de 0,07 en 2007 mientras que en 2010 se redujo a 0,01. La Pesca del pez espada opera durante todo el año, sin embargo, se observa la captura incidental de aves marinas sólo entre mayo y octubre, alcanzando el máximo en el mes de septiembre.