Robards el al : Variation in fish communities of lower Cook Inlet, Alaska 



971 



(Table 7) that were not present in any of the beach 

 seine sets (Tables 1 and 6). Similar proportions of 

 the most abundant taxa were evident in trawl and 

 beach seine samples from Kachemak Bay (Fig. 5), 

 and sand lance dominated both nearshore and off- 

 shore catches. Few midwater trawls were made at 

 Chisik Island because acoustic sign signals rarely 

 indicated that fish were present in the water column. 

 There was moderate overlap in composition of seine 

 and trawl catches at Chisik Island, and no single 

 species dominated the samples (Fig. 5). In contrast, 

 the shelf environment of the Barren Islands was 

 clearly dominated by walleye pollock, and nearshore 



habitats were almost completely populated by sand 

 lance. 



CPUE (defined as catch-per-individual-trawl) for 

 trawl sets varied by an order of magnitude among 

 the three study areas, paralleling results from beach 

 seine sets (Table 2). Geographic trends in commu- 

 nity diversity indices from trawl catches were also 

 similar to those calculated for nearshore beach seine 

 sets (Table 2). Species diversity (H'), species richness 

 (D), and equity (J') were highest at Chisik Island, 

 somewhat lower in Kachemak Bay, and lowest at the 

 Barren Islands (Fig. 5). 



