Predation by Harp Seals in Atlantic Canada: Preliminary Consumption Estimates for Arctic Cod, Capelin and Atlantic Cod

摘要: Current estimates of harp seal (Phoca groenlandica) abundance indicate that the total population size in eastern Canada 1994 was approximately 4.8 million (95% C.I. 4.1– 5.0 million) animals. To estimate consumption important fish prey by seals off coast Newfoundland and Gulf St. Lawrence, a model incorporating agespecific energy requirements, size, seasonal distribution diets developed. Total annual increased from 3.6 to 6.9 tons between 1981 1994. The proportions obtained Arctic Newfoundland/southern Labrador areas were 46% 40%, respectively, while 14% consumed Lawrence. cod (Boreogadus saida) capelin (Mallotus villosus) major most Gulf. Based on an average diet, estimated 2.8 tons, including 1.2 735 000–1.7 cod, 620 000 288 000–1.0 88 46 000– 140 000) Atlantic (Gadus morhua) In Gulf, 445 208 000–727 capelin, 20 0–48 54 14 000–102 out 961 prey. Incorporating seasonal, geographic variations diet provided additional information trends consumption. Basic assumptions varied assess its sensitivity. Changes energetic costs activity growth, abundance, residency period, or proportion offshore can affect significantly.