CONSUMPTION OF MARINE RESOURCES BY SEABIRDS AND SEALS IN CROZET AND KERGUELEN WATERS - CHANGES IN RELATION TO CONSUMER BIOMASS 1962-65

The total annual food consumption of the seabird and seal community br eeding at Iles Kerguelen was estimated to be 1.8x10(6) t in 1985. This biomass included c. 0.99x10(6) t (55%) of crustaceans, 0.46x10(6) t ( 26%) of myctophid fish, 0.07x10(6) t (4%) of other fish species, and 0 .26x10(6) t (15%) of squid. During the same year, the mass of prey con sumed in Crozet waters was previously estimated to be 3.1x10(6) t, the total food consumption in the Indian Ocean area including the two arc hipelagos thus totalling c. 5x10(6) t in 1985. Four species of top pre dators, the king penguin, macaroni penguin, elephant seal, and fur sea l, consumed 59% and 56% of the amount of prey eaten in 1985 by the who le community at Kerguelen and Crozet islands, respectively. Between 19 62 and 1985, population changes of these four species induced 18 and 4 1% increases in their food consumption at Kerguelen and Crozet islands . Population changes included a moderate increase in the number of mac aroni penguins and a marked rise of king penguin populations. Assuming that the diet of king penguin was similar in 1962 and 1985, its popul ation increase will have required a concomitant increase of 0.6x10(6) t in the consumption of myctophid fish in Crozet and Kerguelen waters.