McKenna: Spatial structure and temporal continuity of South Georgian fish community 



485 



CLUSTER 1 



other (9.1%) 

 ACER (3.4%) 



LARS (14 6%) 



GUNN (16.6%) 



ACER 

 PSEU (4.8%) 



CLUSTER 2 



other (54%) 

 (4 5%) 



GIBB (14.1%) 



NUDI (16.2%) 



CLUSTER 3 



(77) 



CLUSTER 4 



other (6 3%) 

 ACER (3.8%) 



olhe ' (4 7%) 

 GIBB (5" 



RARE 



SQUA (9 8%) 



GIBB (10.5%) 



- 



GUNN (22.5%) 



GUNT 

 -(35.8%) SPECIES 

 — ]ANGU 

 (KEMP 

 ICARE 

 CENT 

 DIPL 

 HARP 

 LIPA 

 MELA 

 NICH 



MICR (6.7%) 



LARS (17.2%) 



(13) 



(4) 



CLUSTER 5 



other (4 5%) 

 GUNN (6.7%) 



GIBB (10.5%) 



PSEU (13.3%) 



(2) 



Figure 7 



Charts describing the composition of the communities identified by cluster analysis of the 1987-88 AMLR survey data, 

 based on numerical abundance. Pie charts depicting the composition of each community. Stations comprising each 

 cluster are listed horizontally below each chart. The species which accounted for at least 10% of the community are 

 listed to the left of each chart. Bars depicting the presence/absence of the rarest species in each community. Shaded 

 boxes indicate presence. Stations comprising each cluster are listed horizontally below each chart. Species codes are 

 read vertically under each box of a given bar. 



clearly defined. The weakness of the pairwise associa- 

 tions and the nebulous basis for the classification of 

 species into groups suggests the lack of stronger eco- 

 logical ties between some species than others in the 

 community. 



Normal (r?-mode) clustering of sample sites based 

 on both species assemblages and size structure of each 

 species' population indicated the lack of spatial struc- 

 ture in the community, as well. The movement of fish 

 towards deeper water as they grow larger offers a pos- 



