The size of fish in the catches 

 also had an important bearing on the 

 summer yield in most areas in 1957. 

 The data presented in tables 9 and 10 

 showed that the average size of fish in 

 the donninant age groups contributing 

 to the summer catches was the smallest 

 in the past 3 years. The significance 

 of this finding perhaps is most evident 

 from an example provided by the fish- 

 ery in the Middle Atlantic Area. In 1956 

 an estimated 1.3 billion fish produced a 

 catch of 402,000 tons, whereas in 1957, 

 1.4 billion fish contributed a catch of 

 only 342,000 tons. 



A possible explanation for the 

 smaller size of fish of ages 1 and 2 in 

 the 1957 summer catches is that pre- 

 vailing drought conditions may have 

 reduced the available plankton food 

 supply in the inshore waters where 

 these age groups normally are con- 

 gregated in greatest abvmdance. Pre- 

 cipitation during June, July, and August 

 generally was less than 50 percent of 

 normal from the Carolinas to southern 

 New England (U. S. Weather Bureau, 

 1958). It also was pointed out (p. 5) 

 that in contrast to previous summers, 

 schools in the Middle Atlantic Area 

 occurred farther offshore where they 

 were less accessible to capture in the 

 deeper waters. The larger fish in the 

 younger age groups, therefore, may 

 not have been represented in the catches 

 in proportion to their actual abundance 

 in the stock, resulting in a reduction 

 in size of fish caught. An alternative 

 hypothesis is that the relatively greater 

 nunnber of fish in the 1955 and 1956 

 year classes increased competition 

 for food--i.e., less food was available 

 to the individual --and growth conse- 

 quently was reduced. 



It also should be pointed out that 

 the decrease in average size of fish in 

 the younger age groups in the summer 

 catches could have resulted from in- 

 creased fishing effort. Along this line, 

 it is of interest to note that the greatest 

 relative decrease in average size of 

 fish occurred in the Chesapeake Bay 

 and Middle Atlantic Areas where in- 

 creases in fishing effort have been 

 proportionately greatest. Further in- 

 vestigation of this apparent relation- 

 ship appears to be highly desirable. 



SUMMARY 



This, the third in a series of re- 

 ports, summarizes and discusses 

 data obtained from the catch- 

 sampling program conducted by th3 

 Bureau of Commercial Fisheries 

 on the menhaden stocks along the 

 Atlantic coast of the United States 

 in 1957. The purpose of the sannpling 

 program is to furnish data for 

 determining the relation between 

 fluctuations in the catch and changes 

 in the connposition of the Atlantic 

 menhaden (Brevoortia tyr annus) 

 population. 



The 1957 purse-seine catch of At- 

 lantic menhaden amounted to 632,000 

 tons, of which 576,000 tons were 

 taken in the "sumnner" fishery. 

 The catch was 14 percent below 

 that of the previous year, and the 

 fishing effort expended in taking it 

 (31,600 sets) was 8 percent greater. 

 The Middle Atlantic Area furnished 

 the greatest portion of the catch 

 (54 percent), while the South At- 

 lantic Area furnished the least (7 

 percent). Catch per unit of effort 

 in the summer fishery declined 

 from that of the previous 2 years 

 in all areas except Chesapeake Bay, 

 while in the North Carolina fall 

 fishery it was greater than that of 

 the previous year and nearly 

 equalled that of 1955. 



The 1957 fishery could be charac- 

 terized as spotty. In the South 

 Atlantic Area, adverse weather was 

 partly responsible for the sporadic 

 fishing off Fernandina, Fla., and 

 Southport, N. C. In Chesapeake 

 Bay, numerous small schools pro- 

 vided productive fishing through 

 the entire summer. Drought con- 

 ditions during June, July, and August 

 may have been responsible for the 

 shifty availability of schools in the 

 inshore coastal waters of the Mid- 

 dle and North Atlantic Areas. Liarge 

 schools which congregated off 

 southern Long Island in October 

 produced the heaviest vessel 

 catches of the entire summer fish- 

 ery. Although fish were present in 

 abundance on the North Carolina 



19 



