Are deep-sea cephalopods really common preys for oceanic seabirds?

an analysis of published data on oceanic seabirds diets, show the predominance of muscular cephalopods with superficial distribution in the oceanic layers, but also important are the gelatinous and ammoniacal species restrict to layers below 300 m from the surface. in principle, it could be not expected that deep-sea cephalopods are common prey for seabirds like several authors have been concluded. it is proposed in this study that an indirect source, important and easily attainable, have been appeared with the beginning of tuna longline operations. the habit to feed upon viscera of the fishes captured by tuna longliners, that discard the gut contents to the water, may explain the probable equivocal conclusions that deep dwelling cephalopods are natural prey of oceanic seabirds.