FISHERY BULLETIN: VOL. 77. NO, 1 



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FIGI'RE 6 — Location of all American shad catches during sum- 

 mer and winter bottom trawl surveys, 1963-76, Cape Hatteras. 

 N.C., to Nova Scotia. 



uted along the Gulf of Maine and Georges Bank 

 perimeter, as well as south of Nantucket Shoals 

 (Figure 7). Most of these captures were along the 

 continental shelf at depths of >60 m. Monthly 

 catches indicated a southward movement out of 

 the Gulf of Maine in late autumn, although some 

 shad remained there into November. During lOyr 

 of autumn bottom trawl surveys along the Middle 



204 



Atlantic States, shad were never collected offshore 

 south of lat. 39°N. 



The relatively low number of successful trawl- 

 ing stations during the winter may be inadequate 

 to define the southern limit of the wintering area 

 (Figure 6). Winter catches occurred at 22 stations 

 from southern Long Island (lat. 39°N) to the 

 southern edge of Georges Bank (lat. 41''N) and 

 reflected the same general area where shad began 

 congregating in autumn ( Figure 7). Except for two 

 shallow-water stations, winter collections of shad 

 were made at a mean depth of 108 m. 



DISTRIBUTION OF 

 INTERNATIONAL CATCHES 



The season for major shad catches in ICNAF 

 divisions (Figure 8) agreed closely with distribu- 

 tion according to bottom trawl surveys. Largest 

 annual catches were reported by the United States 

 in Subarea 6 ( 1,517-2,812 1). United States catches 

 between 1970 and 1976 occurred primarily in Di- 

 vision 6B and ranged from 112 to 1,272 t in March 

 and April. Most of this spring catch was taken by 

 the inshore commercial fishery. The only other 

 catch of comparable size was made in Division 5Ze 

 by the Federal Republic of Germany during Sep- 

 tember 1973 and totaled 302 t. Catches in Subarea 

 5 occurred mainly in autumn; however, winter 

 catches were reported in Division 5Zw and 6A 

 between New Jersey and Cape Cod. Canadian 

 catches in Subarea 4 were greatest in May, with 

 decreasing catches throughout the summer. 



DISCUSSION 



The sampling design of NMFS bottom trawl 

 surveys covers a large area in a relatively short 

 period of time and provides good data on fish dis- 

 tribution and concurrent environmental condi- 

 tions. Even though these surveys were initially 

 designed to sample primarily demersal species, 

 results do reflect major changes in the abundance 

 of pelagic species as well (Schumacher and An- 

 thony'; Anderson*). Bottom trawls used during 

 U.S. surveys are less effective on A/osa spp. than 



'Schumacher, A., and V. C. Anthony. 1972. Georges Bank 

 (ICNAF Division 5Z and Subarea 6) herring assessment. Int. 

 Comm. Northwest Atl, Fish. Anna. Meet. 1972. Res. Doc. No. 24, 

 Serial No. 2715. 36 p. 



"Anderson, E. D. 1973. Assessmentof Atlantic mackerel in 

 ICNAF Subarea 5 and Statistical Area 6. Int. Comm. North- 

 west Atl. Fish. Annu. Meet. 1973. Res. Doc. No. 14. Serial No. 

 2916, 37 p. 



