The autumn plot (Figure 1.2) shows some offshore distribution to about the 

 mid-shelf, but the population is still mainly concentrated inshore. 



The grapns of mean weight and number per tow (Figures 1.4-1.7) generally 

 reflect the importance of the inshore strata areas. The frequent occurrence 

 of large numbers of fish in strata set 6 is the result of a combination of 

 offshore overwintering and the first appearance of northerly-migrating smooth 

 dogfish from south of Cape Hatteras. The extraordinarily high numbers and 

 weights during 1974 in Figures 1.4 and 1.6 result from a few large tows. 



Length frequencies from the strata sets, arranged by seasons, are shown 

 in Figures 1.8-1.18. These frequencies suggest that, with the exception of 

 young-of-the-year (YOY), all size ranges were represented in our survey 

 tows. A spring plot for strata set 4 was omitted because no fish were caught 

 in that area. 



Figures 1.19 and 1.20 show the percentage occurrence by stratum of YOY. 

 The cutoff length was 32 cm for both the spring and fall series. Very few YOY 

 smooth dogfish were caught on NMFS surveys because they remain in very shallow 

 water until they reach 50 cm. Because of the very light catches, no patterns 

 are discernable in the YOY plots. 



Since there is no directed fishery for smooth dogfish, and in fact 

 fishermen try to avoid areas inhabited by significant numbers, the species has 

 not oeen extensively studied. The smooth dogfish is a voracious bottom feeder 

 and the ecological impact in areas of high density must be considered 

 important . 



22 



