sorted fish brought in through the kindness 

 of the trap boat captains. 



This characteristic, changing composition 

 of the catches at Newport and Fire Island 

 is shown in figure 6 and tables 14 and 15. 

 Figure 6 allows comparison with New Jersey 

 catches as to age and size of fish. Choosing 

 the 1927 class for comparing the effects on 

 the catch of successful reproduction by sev- 

 eral consecutive broods, we find that if ef- 

 fected sudden record high catches in the New 

 Jersey fishery beginning in 1929; and, although 

 it did appear at Newport and Fire Island in 

 1929, it accounted for a smaller proportion 

 of the catch and did not become dominant 

 there until 1930. Similarly, the 1928 class. 



which contributed greatly to the New Jersey 

 pound catch for the first time in 1930, did not 

 attain dominance at Newport and Fire Island 

 until 1931. 



These differences in fluctuations of the New 

 Jersey fishery compared with that of New 

 York-southern New England may be explained 

 in part (1) by differences in the age and size 

 composition of the catches and (2) by fishing 

 practices affecting the reported amounts 

 caught. For instance, both fisheries show 

 upward trends in catch per trap in recent 

 years of about the same percentage increase, 

 but differ in magnitude and in individual years 

 (fig. 4). This might be explained on the basis 

 that the catch of a fishery depending on the 



Table 14. — Length frequencies of scup in random samples from the catch by floating traps near 



Newport, R.I., 1930-31 



[Number of fish] 



29 



