42 U. S. BUREAU OF FISHERIES 



The number of recaptured tagged fish recorded up to Jfovember 

 24, 1924, is 457, segregated as follows : 



Tagged in 1923, recaptured in 1923 by fishermen 128 



Tagged in 1923, recaptured in 1923 by the Ilalcyon 43 



Tagged in 1923, recaptured in 1924 by fishermen 86 



TagiU'ed in 1923, recaptured in 1924 by the Halcyon 39 



Tagged in 1924, recaptured in 1924 by fishermen 119 



Tagged in 1924, recaptured in 1924 by the Halcyon 102 



517 



There are now eight instances of tagged fish being recaptured 

 twice, all of them codfish. In each case the Halcyon made the first 

 recapture, liberating the fish after obtaining the record. Three of 

 the second recaptures were made by the Halcyon and five by fisher- 

 men. Six of these fish Avere taken each time in the locality where 

 tagged, while two had migrated from Nantucket Shoals to Rock- 

 away, N. Y. 



Although no pollock are included in the preceding lot, pollock No. 

 16418 holds the unique record of having been recaptured three times, 

 each time by the Halcyon at Great Round Shoal whistling buoy, 

 Nantucket Shoals, Mass, The record of this fish follows: Tagged 

 October 15, 1923, length 221/2 inches; recaptured July 16, 1924, 

 length 23 inches; recaptured September 11, 1924, length 231/^ inches; 

 recaptured October 26, 1924, length 23i/^ inches. 



Platts Bank, also called New Ledge, lies more than 30 miles from 

 the nearest land, off Portland, Me., has a depth of 29 to about 50 

 fathoms and an area of about 35 square miles. Of 174 cod tagged 

 in this locality the latter part of July, 1924, the Halcyon recaptured 

 3 on August 15, although only 48 cod were caught on that date. 

 This instance was considered remarkable, but subsequent records 

 have proved even more so. A total of 218 cod was tagged on Platts 

 Banlc last summer, and 22 have been recaptured by Portland fisher- 

 men. Of these 22 fish, 2 were included in the 3 fish recaptured by 

 the Halcyon on August 15, being, therefore, second recaptures. 



The scales of more than 10,000 cod, pollock, and haddock were 

 taken during this period for use in a study of age. It has been 

 determined that one of the most important parts of the cod scale 

 is that which registers the first year's growth, for from this it may 

 be possible to tell whether a fish Avas hatched in the full, midAvinter, 

 or spring. A careful study of this kind might rcA^eal Avhether 

 schools of cod remain together during a large part of their lives, 

 whether a fishing ground is populated with cod hatched during 

 various seasons (and therefore probably originating from various 

 localities), or whether the opposite might prevail. A careful study 

 of the cod scale indicates that a large amount of important data 

 might be obtained from this source. The possibilities here are very 

 promising indeed. The pollock scale and the haddock scale, too, are 

 very satisfactory as a means for age determination. During 1924 

 an excellent series of scales Avas obtained from each of these species. 



The results of the North Atlantic fish-tagging operations during 

 the past two years haA^e been so satisfactory that tagging Avill be 

 resumed in 1925. Considerable information already has been ob- 

 tained on age, rate of growth, and migration of these important food 

 fishes. 



