FISHERY BULLETIN: VOL. 79. NO. 3 



ter life history is similar to that of the alewife, 

 although its biology has not been as rigorously 

 studied (Scherer 1972; Loesch and Lund 1977). 

 Adults appear in rivers about 1 mo later than ale- 

 wives and spawn over an extended period, at water 

 temperatures between 21° and 24° C (Bigelow and 

 Schroeder 1953). The young leave freshwater dur- 

 ing their first year and remain in the ocean for 2 to 

 5 yr before returning to spawn. 



This paper presents information on the offshore 

 distribution and seasonal movements of these 

 river herring, based on cruise and catch data col- 

 lected during bottom-trawl surveys from 1963 to 

 1978 by U.S. research vessels between Cape Hat- 

 teras, N.C., and Nova Scotia, Canada. 



METHODS 



The National Marine Fisheries Service (NMFS) 

 and its predecessor agency, the Bureau of Com- 

 mercial Fisheries, have conducted bottom trawl 

 surveys each autumn since 1963, using the RV 

 Albatross IV and the RV Delaware II. The survey 

 area, which extended from Nova Scotia to Cape 

 Hatteras out to a depth of 366 m (Figure 1), was 

 stratified into geographical zones based on depth 

 and area. Coastal sampling stations were outside 

 the 27 m depth contour. Middle Atlantic stations 

 between New Jersey and Cape Hatteras were 

 added during autumn 1967. A stratified, random 

 sampling design was used in the surveys; trawl 

 stations were allocated to strata in proportion to 

 stratum area and randomly assigned within 

 strata (Grosslein 1969). A standard No. 36 Yankee 

 bottom trawl with a 1.25 cm stretched mesh cod 

 end liner was towed at each station for 30 min at 

 an average speed of 3.5 kn. Fall surveys were con- 

 ducted 24 h/d between 3 September and 16 De- 

 cember 1963-78. 



Bottom trawl surveys were conducted each 

 spring during 1968-78 by U.S. vessels over the 

 same geographical area (Figure 1). The No. 36 

 Yankee trawl was used from 1968 to 1972 and a 

 larger No. 41 Yankee trawl from 1973 to 1978. 

 Trawling procedures were the same as during au- 

 tumn surveys, and stations were sampled between 

 4 March and 23 May. Spring and fall cruises were 

 each conducted within an 8-wk period. A detailed 

 description of NMFS bottom trawl surveys and 

 survey procedures was provided by Flescher^ and 

 Grosslein.^ All spring and autumn surveys and 

 additional cruises during summer and winter are 

 summarized in Table 1. 



Figure L — National Marine Fisheries Service bottom trawl 

 survey area, between depths of 27 and 366 m, Cape Hatteras, 

 N.C., to Nova Scotia, western North Atlantic. Contour intervals 

 are in meters (from Neves and Despres 1979). 



^Flescher, D, 1976. Research vessel cruises, 1963-1975 Na- 

 tional Marine Fisheries Service, Woods Hole, Massachu- 

 setts. NMFS, Woods Hole, Mass., Lab. Ref No. 76-14, 30 p. 



^Grosslein, M. D. 1969. Groundfish survey meth- 

 ods. NMFS, Woods Hole, Mass., Lab. Ref No. 69-2, 34 p. 



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