Fishery Bulletin 103(1) 



£ 25- 



20 



10 



25 Mean 50 75 100 



Discarded 



1 25 



Mean 50 



Percentile 



75 100 



Figure 3 



Percentiles of scup {Stenotomus chrysops) length frequency for those tows in which 

 discards exceeded or failed to exceed landings for landed and discarded scup. "M" 

 represents this study and "N" represents NMFS observer data. Landed, less disc. 

 = for scup landed, tows with less discarded scup than landed scup. Discarded, less 

 disc. = for scup discarded, tows with less discarded scup than landed scup. Landed, 

 more disc. = for scup landed, tows with more discards of scup than landed scup. 

 Discarded, more disc. = for scup discarded, tows with more discards of scup than 

 landed scup. l = smallest size. 100=largest size. 



and the total catch of all species (P=0.0195) and total 

 discards of all species (P= 0.0004) were higher in tows 

 taken during the last half of the trip (Table 6). More 

 scup being landed and discarded in the last half of the 

 trip indicates that captains learn where to fish for scup 

 during the trip and CPUE rises as a consequence. No 

 evidence exists that discards increased with respect to 

 landings during the trip. 



We anticipated that reduction of the trip limit from 

 4536 kg to 454 kg on 24 January would influence 

 the total weight of discards. Time did influence total 

 weight of scup discards (P=0.0056) in our study. More 

 discards per tow occurred on trips taken prior to 24 

 January, likely because of the larger trip limit (weight 



limit per species for each trip) for the 1-24 January 

 period. With a larger trip limit, more scup can be 

 caught per tow and therefore more scup will be dis- 

 carded. The discards-to-landings ratio, however, was 

 not significantly affected — indicating that captains 

 controlled total scup catch in proportion to the land- 

 ing limit. 



The present study versus the NMFS observer study 



We compared trends in our data with those in the NMFS 

 observer data. The subset of directed scup tows in the 

 two data sets rarely disagreed, despite the disparity in 

 codend mesh sizes reported (Table 1). 



