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



these tows, reflecting the overall larger size of the scup 

 catch in tows where total catch was relatively low. 



Finally, for tows in which scup discards exceeded 

 landings, total catch of all species and total discards of 

 all species were also high. This trend was significant 

 for total catch (P=0.0273) and total discards (P=0.0038) 

 in our study (Table 5) and for total discards (P= 0.0017) 

 and total catch (P=0.0112) in the NMFS observer data 

 set (Table 5). Therefore, scup discards tended to increase 

 with respect to landings as total catch increased. 



Time and effort 



For our study, effort significantly affected the 25 th 

 (P=0.0247) and 50 th (P=0.0466) percentiles of the size- 

 frequency distribution of discards. The size frequencies 



for landings were not similarly affected. In both former 

 cases, the 25 th and 50 th percentile sizes were larger when 

 effort was less (shorter tows). No significant effects were 

 observed in the NMFS observer data set. Because the 

 length frequency of the entire catch did not change sig- 

 nificantly, this is likely an effect of processing onboard 

 the boat. 



Given trip limits, one might anticipate discards to 

 increase in tows made at the end of the trip. We ex- 

 amined the amount of scup caught either in the first 

 half of the tows or in the last half of the tows on each 

 trip. For this study, more scup were landed (P= 0.0008) 

 and discarded (P=0.0001) in tows that occurred during 

 the last half of the trip. Total catch and total discards 

 were unaffected. For the NMFS observer data set, more 

 scup were landed (P=0.0001) and discarded (P=0.0001) 



