BUREAU OF FISHERIES XXI 



not indicate the production of an}^ year class at all comparable to 

 those of the earlier period. 



Work carried on during the past year both at sea and on shore 

 has shown that there is now present on the banks a group of small 

 haddock forming the most numerous year class which has appeared 

 during the past several years. It is anticipated that as this abundant 

 group grows in size the landings of scrod will increase and during 

 1932 and 1933 a proportional increase in the landings of large had- 

 dock should occur. With favorable market conditions therefore the 

 outlook for a more successful haddock fishery is bright. 



A continued study of fluctuations in the mackerel fishery is also 

 producing results that should be of great value to the industry. By 

 studying'the condition and trend of this fishery, which yielded 

 64,000.000 pounds in 1929, it is possible not only to discover depletion, 

 should it occur, before it becomes disastrous to the industry but also 

 to issue predictions of future yields which permit an adjustment of 

 distributing facilities and expenditures for production and prevent to 

 some extent the demoralizing effects of glutted markets. As a result 

 of such studies a prediction was issued in May at the beginning of 

 the mackerel season which estimated the quantities of mackerel in the 

 sea to be sufficient to yield 26,000,000 pounds of commercial size 

 exclusive of 1931 tinkers, providing the same number of vessels oper- 

 ated with the same intensity of fishing as during the last year. The 

 prediction of the previous year of 35,300,000 pounds exclusive of 

 1930 tinkers was surprisingly close. The actual yield of the sizes of 

 fish considered was 32,164,000 pounds, while the total catch for the 

 season was approximately 36,472,000 pounds. 



In order to provide a more complete understanding of the causes 

 of fluctuations in abundance, observations on the spawning grounds 

 from Cape Cod to North Carolina were continued. Oceanographic 

 observations were made on ocean drifts, on the abundance of eggs 

 and larvae of the mackerel, and experimental studies on the rate of 

 development of mackerel eggs under varying conditions of temper- 

 ature were carried out. 



Limited observations on the migrations of the cod by means of 

 tagging experiments confirmed and extended previously published 

 conclusions. Similar studies were also conducted on the important 

 shore fishes of the Middle Atlantic States, including the squeteague 

 or weakfish, scup, butterfish, sea bass, and summer flounder. The 

 relationship of production areas from Chesapeake Bay northward 

 has been clemonstrated and variations in the supply of these im- 

 portant fishes are now believed to follow the same principle of domi- 

 nant year classes demonstrated for the haddock and mackerel. Dur- 

 ing the past two years commercial trawlers have located and are 

 exploiting these species on their winter feeding grounds off the 

 Virginia capes. A study of the migrations and varying abundance 

 of these species is being extended to include the offshore areas in 

 order to determine what the probable effect will be of the winter 

 drain upon the supply which heretofore has been exploited only in 

 the summer seasons. 



Investigations of fishery problems in the South Atlantic and Gulf 

 include the shrimp fishery from North Carolina to Texas, oyster 

 culture in the coastal area from North Carolina to Florida, and 



