CCAMLR

This paper describes in detail a method for obtaining food samples from Pygoscelid penguins and some suggested modifications to CEMP Standard Method A8. It proposes a new method for draining the water from samples, an extension of the sampling period to include the guard phase, and that birds found to be empty of food be included in the data set if they are bona fide breeders. It also suggests that the first regurgitate of each sample be kept separate from the remainder because it often consists of organisms that have been collected adventitiously by the bird on its return journey to the colony. Previous papers which have reported diet composition on the basis of a single regurgitate per bird are likely to be biased toward neritic species (amphipods, Pleuragramma antarcticum and Euphausia crystallorophias) and may underestimate the importance of E. superba in the diet of penguins from some region

The diet of lactating female Antarctic fur seals Arctocephalus gazella at South Georgia was investigated during the pup rearing period (January - March) of 1991-1994. Antarctic Krill Euphausia superba was the main prey item, occurring in 88% of all scats (n=497), whereas fish occurred in 47% and squid in 5%. There was considerable intra and inter-annual variation in the characteristics of krill taken by fur seals. The distribution of krill sizes taken suggest that fur seals are not actively selecting particular sizes of krill and, therefore, that the krill in the diet reflects the krill available around South Georgia. The absence of group 3 krill (44-48 mm in length) in the South Georgia area, as indicated by there absence in the diet of seals, is suggested as a possible reason for low availability of krill and the subsequent reproductive failure among krill predators. The frequency of occurrence of fish was much higher than in previous studies; the pattern of fish consumption showed a consistent seasonal pattern in three of the four years studied. Of the total number of the myctophid Protomyctophum choriodon, the most numerous - fish taxon, 98% were taken between early February and the middle of March. Champsocephalus gunnari and Lepidonotothen larseni agg., which both feed on krill, dominated the fish component of the diet outside this period and together constituted 94% of the total estimated biomass of fish consumed. The intra and inter-annual variability in the diet of Antarctic fur seals emphasises the need for diet studies to be conducted during the entire pup-rearing periods of several years.