Bochenek et al.: Assessment of Stenotomus chrysops and Centropnstas striata discards in the Mid-Atlantic Bight 



Landed 



I Landed, less disc. 

 I anded, more disc 



Discarded 



I Discarded, less disc. 

 Discarded, more disc 



I 25 Mean 50 



Percentile 



Figure 5 



Percentiles of black sea bass (Centropristas striata) length frequencies for those 

 tows in which discards of black sea bass exceeded or failed to exceed landings for 

 landed or discarded black sea bass. Landed, less disc. = for black sea bass landed, 

 tows with less discards of black sea bass than what was landed. Discarded, less 

 disc. = for black sea bass discarded, tows with less discards of black sea bass 

 than what was landed. Landed, more disc: for black sea bass landed, tows with 

 more discards of black sea bass than what was landed. Discarded, more disc. = 

 for black sea bass discarded, tows with more discards of black sea bass than 

 what was landed. l = smallest size. 100 = largest size. 



50 th (P=0.0280), and the 75 th (P=0.0090) percentile size 

 fractions and the mean length (P=0.0133). The size of 

 landed black sea bass was larger in tows where discard- 

 ing was low (Fig. 5). 



Time and effort 



Because of trip limits, discards could increase in tows 

 taken near the end of a trip. Therefore, we compared the 

 catch of black sea bass in the first and the last half of 

 the tows. The quantity caught and the length-frequency 



percentiles were not significantly different between the 

 first and last half of the tows. In contrast, for scup trips, 

 discards and landings tended to be higher in tows made 

 in the last half of the trip. 



Effort significantly affected the 25 th (P=0.0010), 50 th 

 (P= 0.0003), and 75 th percentile (P= 0.0153) size fractions 

 of black sea bass for the combined data sets (NMFS 

 study and our study). In these cases, higher effort was 

 associated with more smaller fish. When the two data 

 sets were analyzed independently, most of the effort 

 effects were no longer present. 



