204 U. S. BUEEAU OF FISHERIES 



Summary of recaptured fish reported up to DecemJ)er 31, 1927 — Continued 



There are records of 44 cod recaptured a second time, the first 

 recapture having been made by one of the tagging vessels, which 

 returned the fish to the water. No marked pollock or haddock were 

 caught more than once, with the single exception of pollock No. 

 16418, mentioned in previous reports, which was recaptured three 

 times. 



Not included in the preceding tables are 946 cod tagged at Woods 

 Hole, Mass., on January 6 and 7, 1926, of which 20 have been recap- 

 tured ; and 422 cod tagged on January 3, 1927, of which 8 have been 

 recaptured. These fish were caught near by during November and 

 held for their spawn at the bureau's biological station. 



Scale samples have been taken from all fish tagged during and 

 since 1924, and about 1,000 of these have been studied. Although 

 it appears possible to secure from the scales desirable data on age 

 and growth, definite conclusions as to these factors can not yet be 

 stated. One of the chief difficulties encountered in the study of cod 

 scales lies in the interpretation of evidence of early growth. To 

 assist this study, quite a number of small cod, 2 to 9 inches long, 

 were taken by bottom trawls in the vicinity of the tagging grounds. 

 It is very likely that a careful study of this material will be of value 

 in determining the age of older fish. 



Tagging from 1923 to 1925 was done by the Halcyoiv on the shore 

 grounds from Nantucket Shoals to Mount Desert, Me. The Albatross 

 11^ a larger and more seaworthy vessel, replaced the Halcyon in 

 1926. Operations did not commence that year until August, when 

 the first cruise was made offshore to the northeastern part of Georges 

 Bank and Browns Bank and Cashes Ledge were fished. In Novem- 

 ber, a tagging cruise was made to the Cholera Bank, between northern 

 New Jersey and western Long Island. 



One of the chief difficulties encountered in the present investigation 

 has been the great loss of tags from the fishes' tails, even during the 

 first year. Two years ago this loss was conservatively estimated at 

 about 60 per cent for the first year, but more recent data have raised 

 this to 70 per cent. This loss made it imperative to modify the 



