Though South Georgia and Bouvet Island are located at the same latitude, the growth and maturation rates as well as the average minimal sizes of E.superba are appreciably higher in the former than in the latter area. This is attributed to milder climatic conditions and better food supply in the South Georgia area as compared to Bouvet Island. The differences in the growth and maturation rates of E.superba between these two areas persist with a change of climatic epochs. During the warmer climatic epoch maturation in both areas begins earlier and stops later than during the colder epoch. Two spawning peaks are observed during the warmer and one peak during the colder epoch.
Abstract:
Analysis of original and literature data for the past 10 years pertaining to the region -of the Antarctic Penunsula and adjacent waters points to a relationship between the distribution of krill and the waters of two major circulation systems - those of the Weddell Sea and the Bellingshausen Sea inhabited by separate subpopulations of the species. The latter are predominant in the region while the proportion of the Weddell Sea krill increases eastward, primarily in the Bransfield Strait but also off the Mordvinov Island. Seasonal coastward migrations (Siegel's suggestion) may actually result from the fact that waters of each of the two major modifications carry out krill into the eastern part of the region at different times. Isaacs-Kidd trawl surveys yielded krill biomass values of 1233±41% and 1708±30% thousand tons in March and December-1984 respectively for the area south of 60°S between 60 and 52°W. The frequency of occurrence of krill aggregations in the area between 75 and 52°W was estimated. For this area, the 1984 survey data yielded krill biomass estimates of 3.27 to 7.89 million tons.
