Brodeur et al.: Summer distribution of early life stages of Theragra chalcogramma 



607 



Day hauls 



Night hauls 



P<0.01 



 Anchovy 



D M.lhol 



P<0.01 



o 



o 



c 



15 20 



40 45 



I I I I I I I 

 15 20 



35 40 



P = 0.12 



P = 0.99 



JU 



tlL 



15 20 26 30 36 40 45 



15 20 25 30 35 40 45 



Standard length (mm) 



Figure 3 



Comparison of the length distributions by haul for the Methot and anchovy trawls for the four 

 paired comparisons done at different stations. Also shown are the results of a Kolmogorov-Smirnov 

 test in which the distributions of each gear type were compared. 



(Fig. 8). Sebastes spp. catches also comprised rela- 

 tively small larvae and were found almost exclusively 

 at offshore stations but were evenly distributed 

 among these stations (Fig. 8). 



Species associations 



The Recurrent Group Analysis identified one main 

 grouping of taxa that showed a common affinity level 

 of at least 0.40 (Fig. 9). Curiously, the nine taxa with 

 the highest densities were members of this group- 

 ing, even though the groupings are formed on the 

 basis of common occurrences. Zaprora silenus lar- 

 vae were associated with eight of the nine taxa but 

 showed a low association with Sebastes spp. larvae. The 

 larval and juvenile stages of T. chalcogramma and G. 

 macrocephalus occurred within the same species group- 

 ing and thus were not differentiated in this analysis. 



The TWINSPAN results were similar to the Re- 

 current Group Analysis in that a large grouping was 

 formed. However, in this instance, Sebastes spp. lar- 

 vae were not closely related to this grouping, but 

 Ammodytes hexapterus larvae were related (Fig. 10). 



H. elassodon 



T. chalcogramma 



A. stomias 



Icelinus spp. 



Liparis spp. 



G. macrocephalus 



Sebastes spp. 



P. bi I meal us 



B. alascanus 



Lumpenus spp. 



A. hexapterus 



P. isolepis 



Z. silenus 



Pleuronectes sp. II 



E. zachlrus 



6 



7 8 9 10 



Log 10 number 



Figure 4 



The estimated total abundance in the survey area for the 

 15 most abundant taxa collected in the Methot trawl sur- 

 vey. Abundances for Theragra chalcogramma, Gadus 

 macrocephalus, and Zaprora silenus include combined to- 

 tals for larval and juvenile stages. 



