Consumption of krill by minke whales in Areas IV and V of the Antarctic

The consumption of Antarctic krill (Euphausia superba) by the southern minke whale (Balaenoptera acutorostrata) in Areas IV and V of the Antarctic was estimated from diurnal change in the forestomach content mass, standard metabolism and the body mass increase methods based on JARPA (the Japanese Whale Research Program Under Special Permit in the Antarctic) data. Estimates of the daily food consumption rate obtained from the three methods ranged from 3 to 4 %. Consumption estimates during austral summer in Areas IV and V were 14.7 - 17.8 x 105 t and 63.2 - 77.0 x 105 t, respectively. The values in Area IV were equivalent to roughly one - fourth of a total estimate biomass of krill in Area IV. Consumption in Area V by minke whales was an order of magnitude greater than the estimated consumption by adelie penguins and crabeater seals. These results indicate the importance of minke whales to the ecosystems in Areas IV and V during the austral summer.