Food and feeding ecology of the sword-fish Xiphias gladius in the western North Atlantic Ocean with estimates of daily ration

Analysis of stomach contents and predator-prey relations of 168 swordfish from the western North Atlantic Ocean is presented.The predominant food of swordfish is squid (82 % by frequency of occurrence) followed by fish (53 % ) consisting primarily of gadids, scombrids, butterfish, bluefish, and sand lance.Average food volume in stomachs is 1 % of average body weight.Estimates of daily ration range from 0.94 % to 1.6 % of average body weight, with yearly consumption ranging from 3.4 to 5.8 times average body weight per year.The prey biomass consumed by the swordfish population in the Georges Bank area is estimated to range from 2,100 to 11,000 mt over a residency time of 5 mo.