470 



Fishery Bulletin 98(3) 



cr 

 0) 



o 15 



A Southern sand flathead 



JLOl 



 Spectra-l-mm n = 65 

 D Control n= 105 



Jj at 



llMI I III 



±_y 



 MomoJ-1 7-mm n=55 

 D Control n = 88 



ii J ^ n \ I 



30 



35 



B Sand trevally 



C Leatherjackets 



 Spectra- 1 -mm n = 332 

 D Control n = 579 



 Spectra-l-mm n = 690 

 D Control n = 704 



Itl^t-. 



Length (cm) 



Figure 4 



Size-frequency distributions of the new and control trawl bodies for (A) southern sand flathead 

 {Platycephalic hassensis), (B) sand trevally iPseudocaranx wnghti\ and iCi leatherjacket iTham- 

 nacnnus degeni). 



the meshes of the body panels. Likewise in our study, we 

 observed numerous larger individuals of southern sand 

 flathead, leatherjackets, and particularly larger sand trev- 

 ally ( 10-15 cm) trapped in the meshes of the posterior sec- 

 tions of both large-mesh trawl bodies. 



Although the results showed that significantly more smaller 

 prawns escaped from the new trawl bodies than fi-om the con- 

 trol trawl body, the selectivity parameters and associated 95'7( 

 confidence limits (Fig 5; Table 4) were within the range cal- 

 culated in a previous study (Broadhurst et al., 1999) for a 



