Evidence of two stocks of Champsocephalus gunnari in the South Georgia region, CCAMLR fishing Area 48.3

In 1991, the 0 age-class of C. gunnari were sampled at Shag Rocks on 18 January, off Possession Bay, South Georgia during 19-20 January and off much of the north-east coast of South Georgia between to 19 January to 19 February.
The size- frequency of fish at Shag Rocks contained two modes of 31-46mm and 55-87mm SL. however, off Possession Bay only one mode of 25-57mm SL was apparent. Fish in combined samples off the coast of South Georgia were 24-63mm SL. The mean and median sizes of the fish at these locations were all significantly (p<0.001) different.
The size difference between the larger size mode at Shag Rocks and those at South Georgia must be the result of different spawning seasons and/or egg development periods and/or growth rates. This suggests that there are two separate stocks of C. gunnari in a single CCAMLR statistical sub-area.
There is an apparent growth of around 0.76% SL d-1 (0.27mm SL d-1) for larvae on the South Georgia shelf which is comparable with previous reports of early growth in C. gunnari.