Abstract — This study was undertaken 

 to re-assess the level of scup iSten- 

 otomus ehrysops) discards by weight 

 and to evaluate the effect of various 

 codend mesh sizes on the level of 

 scup discards in the winter-trawl 

 scup fishery. Scup discards were high 

 in directed scup tows regardless of 

 codend mesh — typically one to five 

 times the weight of landings. The 

 weight of scup discards in the present 

 study did not differ significantly from 

 that recorded in scup-targeted tows 

 in the NMFS observer database. Most 

 discards were required as such by the 

 22.86 cm TL (total length) fish-size 

 limit for catches. Mesh sizes sl2.7 cm, 

 including the current legal mesh size 

 (11.43 cm) did not adequately filter 

 out scup smaller than 22.86 cm. The 

 median length of scup discards was 

 about 19.83 cm TL. Lowering the 

 legal size for scup from 22.86 to 19.83 

 cm TL would greatly reduce discard 

 mortality. Scup discards were a small 

 fraction (0.4%) of black sea bass (Cen- 

 tropristis striata) landings in black- 

 sea-bass-targeted tows. The black sea 

 bass fishery is currently regulated 

 under the small-mesh fishery gear- 

 restricted area plan in which fishing 

 is prohibited in some areas to reduce 

 scup mortality. Our study found no 

 evidence to support the efficacy of 

 this management approach. The 

 expectations that discarding would 

 increase disproportionately as the trip 

 limit (limit [in kilograms] on catch 

 for a species) was reached towards 

 the end of the trip and that discards 

 would increase when the trip limit 

 was reduced from 4536 kg to 454 kg 

 at the end of the directed fishing 

 season were not supported. Trip limits 

 did not significantly affect discard 

 mortality. 



An assessment of scup (Stenotomus ehrysops) 

 and black sea bass iCentropristas striata) 

 discards in the directed otter trawl fisheries 

 in the Mid-Atlantic Bight 



Eleanor A. Bochenek 

 Eric N. Powell 

 Allison J. Bonner 



Sarah E. Banta 



Haskm Shellfish Research Laboratory 



Rutgers. The State University of New Jersey 



6959 Miller Ave. 



Port Norns, New Jersey 08349-3167 



E-mail address (for E A Bochenek), bochenek@hsrl.rutgers.edu 



Manuscript submitted 6 January 2003 

 to the Scientific Editor's Office. 



Manuscript approved for publication 

 7 September by the Scientific Editor. 



Fish. Bull. 103:1-14(2005). 



Because of regulations, market fac- 

 tors, and other reasons, both com- 

 mercial and recreational fishermen 

 discard some of their catch. Discards 

 are considered one of the principal 

 sources of mortality for many fish 

 species, including those of significant 

 commercial and recreational fisheries 

 (Howell and Langdon, 1987; Glass et 

 al., 1999; Suuronen et al., 1996). 



The Sustainable Fisheries Act 

 (SFA), governing U.S. fisheries man- 

 agement in federal waters, states 

 that "conservation and management 

 measures shall minimize bycatch." 

 Much has been written about the 

 environmental impact of discarding 

 (Mooney-Seus, 1999; Alverson, 1999; 

 Kennelly, 1999). Discard mortality 

 reduces population size by limiting 

 the number of individuals that can 

 reach maturity and spawn. Because 

 EEZ (Exclusive Economic Zone) fish- 

 eries must be managed at B msv (bio- 

 mass at maximum sustainable yield) 

 under SFA guidelines and discards 

 must be included in estimates of the 

 TAC (total allowable catch), discard 

 mortality also reduces total allowable 

 landings. Therefore, discarding is not 

 just an environmental problem; it is 

 a problem that affects all aspects of 

 fisheries. 



A recreational and commercial 

 fishery for scup (Stenotomus ehrys- 

 ops) occurs in the Mid- Atlantic Bight 



(the portion of the U.S. Atlantic coast 

 extending from Cape Hatteras to 

 Cape Cod) and New England regions 

 where scup are caught south and off- 

 shore in the winter and north and 

 inshore in the summer (NEFSC 1 ). In 

 1996, the legal size for commercially 

 caught scup was raised to 22.86 cm 

 total length (TL), more or less coin- 

 cidently with the establishment of a 

 legal codend mesh size of 11.43 cm 

 to reduce discard mortality (MAFMC, 

 1996). Discarding is considered to be 

 an important cause of mortality for 

 this important commercial and rec- 

 reational species (NEFSC 2 ). Kennelly 

 (1999) reported large amounts of scup 



1 NEFSC (Northeast Fisheries Science 

 Center). 2002. SARC 35. 35 th North- 

 east regional stock assessment workshop 

 (35 th SAW). Stock assessment review 

 committee (SARC) consensus summary 

 of assessments. Northeast Fisheries 

 Science Center Reference Document 02- 

 14, 259 p. Northeast Fisheries Science 

 Center, NMFS, NOAA, 166 Water St., 

 Woods Hole, MA 02543. 



2 NEFSC (Northeast Fisheries Science 

 Center). 2000. SARC 31. 31 st north- 

 east regional stock assessment workshop 

 (31stSAW). Stock assessment review com- 

 mittee (SARC) consensus summary of 

 assessments. Northeast Fisheries Sci- 

 ence Center Reference Document 00-15, 

 409 p. Northeast Fisheries Science 

 Center, NMFS, NOAA, 166 Water St., 

 Woods Hole, MA 02543. 



