476 



Fishery Bulletin 91(3). 1993 



SOUTH 

 GEORGIA 



Drake' s 



Passage 



r a>» 



80° U 



\f 



■* itfl^lJT, 





50" U 



40° U 



30" U 



50° S 



60° S 



Figure 1 



Map showing the location of South Georgia Island in the Southern ocean. Inset map identifies samples 

 sited during each of the three AMLR cruises. Each asterisk (*) represents a sample taken during the 

 1986-87 survey. Each triangle ( ) represents a sample taken during the 1987-88 survey. Each square 

 ( ) represents a sample taken during the 1988-89 survey. 



in the demersal fish community (Kock, 1985b, 1986, 

 1991; Kock and Koster, 1989, 1990), there is a need for 

 more basic information about the ecology of these fishes. 

 The effects of natural (or anthropogenic) events on the 

 populations of these animals cannot be accurately 

 judged without a clear understanding of their basic 

 community organization. 



Analysis of Antarctic fish communities has generally 

 been limited to descriptions of the species present and 

 some investigations of their diets. Targett (1981) in- 

 cluded some measures of diversity in his examination 

 of the fish community at three different islands along 

 the Scotia Arc. His research emphasized diets and re- 

 source partitioning, and gives some of the first descrip- 

 tions of relationships between the species based on a 

 quantitative analysis. However, his sampling was lim- 

 ited to one or two locations at each island. More ex- 

 tensive work has been conducted at Elephant Island by 

 Tiedtke and Kock (1989). Their examination of 

 the demersal fish assemblage around that Island 

 found evidence of spatial structure associated with depth. 



A survey program concentrating on the South Geor- 

 gia area was established as part of the U.S. Antarctic 

 Marine Living Resources (AMLR) project. The research 

 described here used the data from that program to 

 examine the spatial structure of the demersal fish com- 

 munity in the vicinity of South Georgia Island and its 

 temporal consistency from 1986 to 1989. 



Methods 



Data used in this study consisted of species abundances 

 (and associated length-frequency information) collected 

 during three research survey cruises in the South Geor- 

 gia area. The abundance of each species in the region 

 was measured both numerically (number/standard tow) 

 and on a biomass (kg/standard tow) basis. 



These surveys were conducted during the austral 

 summers of 1986-87 (29 Nov.-17 Dec. 1986), 1987-88 

 (19Dec.-10Jan.), and 1988-89 (17-28 Jan. 1989). The 

 1986-87 and 1987-88 surveys sampled the abundance 



