Heales et al : Effect of size of subsamples on estimates of catch composition and abundance. 



797 



100 - 

 90 - 

 80 - 

 70 - 

 60 - 

 50 - 

 40 - 

 30 - 

 20 - 

 10 - 



» Upper 95% CI 



a Mean % of species recorded 



• Lower 95% CI 



10 20 30 40 50 60 70 80 90 100 



Percentage of catcti sorted 



Figure 4 



The mean percentage (and 95% CI) of species recorded as increasing percent- 

 ages of catch weight were sorted. Curves were generated from 200 random 

 selections of the numbered order in which subsamples were collected from 

 each catch. 



100 1 

 90 

 . 80 



o 



^ 70 



cn 



c 



I 60 -\ 

 o 50 



cn 



Z 40 ^ 

 S. 30 



20 

 10 



Abundance categories 



ng error 



10 20 30 40 50 60 70 80 90 100 



Percentage of catch sorted 



Figure 5 



The mean percentage of sampling error calculated when estimating the 

 relative abundance of bycatch species grouped into eight categories of rela- 

 tive abundance. Curves were generated from 200 random selections of the 

 numbered order in which subsamples were collected from each catch. 



