PEOGRESS IN BIOLOGICAL INQUIRIES, 1924 17 



INVESTIGATIONS OF FISH AND FISHERIES 



ATLANTIC COAST 



LIFE HISTORY AND MIGRATIONS OF COD, POLLOCK, AND HADDOCK 



This investigation was begun in April, 1923, when the Halcyon 

 made its first cruise from Gloucester to Nantucket Shoals. A second 

 cruise followed in May and a third in June. 



During the present fiscal year a fourth cruise was made in August, 

 a fifth in September, and the sixth and seventh cruises in October. 

 The tagging was concluded on October 17, 1923, for the present 

 fiscal year. These operations have been conducted by William C. 

 Schroeder, scientific assistant, under the general direction of Dr. 

 H. B. Bigelow, of the Museum of Comparative Zoology of Harvard 

 University. As a result of these seven cruises 10,246 fish were 

 tagged. In addition, 891 fish were injured and retained. From 

 these, scales and data were taken to be used in a study of the age 

 and rate of growth. The tagged fish consisted of about 75 per cent 

 cod, 20 per cent pollock, and 5 per cent haddock. About 98 per cent 

 of the fish were tagged on Nantucket Shoals and the remainder at 

 No Mans Land, off Chatham, and in Massachusetts Bay. 



The cooperation of fishermen and those connected with the fishery 

 industry is of prime importance to the success of this investigation. 

 Circulars, posters, and news items were distributed among the fisher- 

 men and periodicals along the coast from Maine to North Carolina. 

 In addition, one of the bureau's assistants gave direct information 

 to numerous fishing boats at Portland, Gloucester, Boston, New 

 Bedford, New York, and other points. An exhibit showing methods 

 of fish tagging was placed in the Tercentennial Exposition, which 

 was held at Gloucester, Mass., during August, 1923. 



Up until the 30th of June the recapture of 218 tagged fish had 

 been recorded. Although this number is but slightly more than 2 

 per cent of the total number tagged, the results have proved of 

 considerable value and interest. It was proved that many of the cod 

 that visit Nantucket Shoals during the spring and summer remain 

 until fall, when a migration takes place to points between Rhode 

 Island and New Jersey and probably still farther south. 



With the exception of one cod taken off Portland, Me., four off' 

 Cape Ann. one off Boston (all during the summer of 1923), and 

 one off Plymouth (the date of which is uncertain), all recaptured 

 fish were taken south of Cape Cod. During the summer numerous 

 tagged cod were recaptured on Nantucket Shoals in practically the 

 same place where they were first marked. To illustrate this ten- 

 dency for the fish to remain in the region where they were tagged, 

 the records show that of nine tagged fish recaptured by the Halcyon 

 on October 15, 1923, one had been tagged in May, six in June, one 

 in September, and one early in October, all on Nantucket Shoals. 

 Of three tagged pollock recaptured the same day, one each had been 

 tagged in June, August, and September, 1923, on Nantucket Shoals. 



To show the movements of the tagged cod from October, 1923, to 

 June, 1924, the following statement has been prepared. A^-liile in 

 some cases the data are meager, nevertheless the migration of cod 



