Bottom Trawl Survey Results 



The cumulative spring and autumn ai stri cutions over the time series are 

 shown in Figures 5.1 and 5.2. The plots show quite dramatically that silver 

 hake were distributed over a large portion of the Mid-Atlantic shelf during 

 each seasonal survey. The spring distribution (Figure 5.1) shows silver hake 

 over most of the shelf, with large catches along the 1U0 m depth contour and 

 north of New Jersey. In Figure 5.3 data from all cruises prior to 1976 have 

 been deleted. This deletion frequently produces a significantly different 

 distribution pattern because of the timing of the surveys, however, this is 

 not evident with silver hake since the basic distribution pattern is the same 

 in both Figures 5.1 and 5.3. The autumn distribution (Figures 5.2) shows the 

 •greatest concentration of fish in southern New England waters with some 

 occurrences along the 100 m contour to southern portions of the area. Inshore 

 catches were few especially south of New Jersey, indicating the southern 

 movement from northern summering grounds had begun. 



The seasonal plots of mean weight and number per tow by year are shown in 

 Figures 5.4-5.7. The recovery of the stocks from low population levels in 

 the late 1960's is apparent. 



Plots of length frequencies by strata set and season are shown in Figures 

 5.8-5.19. During both seasons the adult silver hake were only rarely caught 

 in the inshore Delaware-Chesapeake and North Carolina strata sets (Figures 

 5.9-5.10). Large adult fish greater than 40 cm were caught in significant 

 numbers only in the central and northern strata sets during the spring 

 (Figures 5.8-5.9 and 5.11-5.12). 



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