TABLE 10. — Mean weight (in grams) of fish at each age in samples from purse-seine 



catches, by area and season, 1955-57 



[Numerically dominant year class xmderscored ] 



Area, year 

 and season 



Age 



10 



Mean 



SUMMER FISHERY 



South Atlantic: 



1955 



Jl936 •••••••••• 



jSyj /«•••••••«• 



Chesapeake Bay: 

 1955 



1957 



Middle Atlantic: 



1955 



1956 



1957 



North Atlantic: 



1955 



1956 



1957 



FALL FISHERY 



North Carolina: 



1955 



1956 



1957 



35 



32 



60 



68 



82 



_67 

 83 



U2 

 118 



31 

 28 

 35 



97 



225 

 206 

 149 



190 



166 



116 



94 



125 

 134 



117 



222 



196 



171 



317 

 305 



257 



401 

 395 

 352 



356 

 346 

 452 



155 



176 

 190 



262 

 388 

 181 



404 

 448 

 429 



426 

 44^ 



471 



460 

 516 



540 



157 

 217 



224 



278 



235 



257 



457 

 522 

 589 



494 



521 

 566 



566 

 563 

 606 



327 



505 

 582 

 608 



589 



565 

 607 



648 

 582 

 636 



596 

 629 

 621 



641 

 615 

 638 



690 

 642 



646 



712 

 643 

 535 



691 



658 

 660 



643 



664 



543 

 688 

 630 



732 

 725 

 706 



806 



784 



634 



760 

 766 

 612 



774 



98 



69 



102 



185 

 125 

 108 



385 

 359 

 270 



514 

 522 

 497 



256 

 373 



450 



DISCUSSION 



The 1957 purse-seine catch of 

 Atlantic menhaden was the lowest in 

 the past 3 years, and despite improve - 

 nnents in the efficiency of fishing- - 

 resulting from the introduction of the 

 "power block", larger vessels, re- 

 frigerated holds, and the increased 

 use of aircraft and fish pumps --catch 

 per unit of effort from most sumnner 

 stocks declined. 



Although details of the general 

 recruitment pattern are still largely 

 unknown, the relative contributions by 



various year classes offer at least a 

 partial explanation for the observed 

 variations in the catch in the different 

 areas in 1957. 



Judging from its contribution to 

 the catch at age 1 in 1957 (1.5 billion 

 fish), the 1956 year class appeared to 

 be relatively abundant. The catch per 

 unit of effort of this year class (42,000 

 fish) in 1957, for example, was only 

 about a third less than that of the 1955 

 year class at age 1 in 1956 (65,000 

 fish) and nearly double that of the 1954 

 year class at age 1 in 1955 (23,000 

 fish). Its contribution to the summer 



17 



