FISHERY BULLETIN: VOL. 82. NO. 1 



TABLE 1.— Number of silver hake stomachs examined from each 

 geographic area by year and season. 



recorded. A stomach was considered empty when no 

 food items could be identified and the material found 

 in the stomach weighed <0.001 g. Data were ana- 

 lyzed with FORTRAN IV programs written for use 

 on a Honeywell SIGMA 7 3 computer system located 

 in Woods Hole, Mass. 



Food data are presented in terms of the mean 

 stomach content weight, adjusted stomach content 

 weight (discussed below), and the percentage weight 



'Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



fished, and during fall cruises a standard Yankee No. 

 36 was used. The cod end and upper belly of both 

 trawls were lined with 13 mm mesh netting to retain 

 smaller fish. A scheme of stratified random trawling 

 was conducted within the study area (Fig. 1), and 

 fishing continued over 24 h/d 2 . All tows were 30 min 

 in duration at a vessel speed of 3.5 kn in the direction 

 of the next station. 



Sampling of stomachs was concentrated in three 

 areas: Middle Atlantic, Southern New England, and 

 Georges Bank (Fig. 1). Fish within two length groups 

 (>20 cm and <20 cm) were randomly selected (50 

 fish/group) during each cruise from the bottom trawl 

 survey catches in each area. At each station within a 

 particular area no more than 10 fish were taken for 

 each of the two length groups, and fish were not sam- 

 pled at two consecutive stations. The only exception 

 to this collection method occurred when it appeared 

 (during the cruise) that 50 large or 50 small fish would 

 not be collected within a particular area. In this case, 

 all fish caught were collected in an attempt to obtain 

 the minimum sample size. Stomachs of large fish 

 were excised aboard ship; individually wrapped in 

 gauze with a label denoting vessel, cruise, species, 

 fork length (FL), sex, and maturity; and preserved in 

 3.7% formaldehyde (small fish were preserved whole). 

 In the laboratory the preserved stomachs were in- 

 dividually opened, and their contents emptied onto a 

 0.25 mm mesh opening screen sieve to permit wash- 

 ing without loss of any food items. The stomach con- 

 tents were sorted, identified, counted, and damp 

 dried on absorbent paper. Major prey items and com- 

 monly occurring but relatively minor prey, in terms of 

 weight, were identified to species whenever possible. 

 The wet weight of all stomach content groups was 

 determined to the nearest 0.00 1 g and all information 



'Further details of the bottom trawling techniques may be obtained 

 from the Resource Surveys Investigation, Northeast Fisheries Cen- 

 ter Woods Hole Laboratory, National Marine Fisheries Service, 

 NOAA, Woods Hole, MA 02543. 



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S 



% 



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FIGURE 1.— Offshore areas sampled during bottom trawl surveys 

 conducted by the Northeast Fisheries Center between the years of 

 1973 and 1976, inclusive. 



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