MIGRATIONS OF COR 
43 
Table 
23 . — Cod taqqed on Nantucket Shoals and subsequently recaptured on Nantucket Shoals — 
Continued 
The recaptures given in Table 23 prove conclusively that part of the cod living 
on Nantucket Shoals one summer are to be found there a year or more later. A few 
tagged fish were retaken on the shoals in the winter, in contrast to the lack of recap- 
tures at that time in the Chatham-South Channel region, where a large number of cod 
were caught. That the number of tagged fish taken monthly did not follow more 
closely the fluctuations in the commercial catch (Table 24) was due to the fact that 
much depended upon what part of the shoals the fishermen were operating. Very 
often a large proportion of the cod were caught along the eastern edge of the grounds 
by haddock fishermen and the number of cod tags received from this source was small. 
We have here a good indication that many of the cod living on the shoals remain 
localized for an extended time. This is shown further by the comparison between the 
number of marked fish taken b} r the tagging vessels, which, of course, fished on the 
tagging grounds, with that taken by commercial fishermen who generally fished about 
10 to 40 miles away. Throughout the period from 1923 to 1928 the Halcyon and the 
Albatross II recaptured on the shoals proper 122 Nantucket cod with tags attached, 
among about 24,000 cod caught, whereas commercial fishing boats reported only 137, 
among a catch of about 866,000. To make this difference more striking, the time 
element between the dates of tagging and recapture was very much the same for the 
fish retaken by fishermen and those retaken by us. The average number of days the 
fish recaptured by us were at liberty was 72 in 1923, 232 in 1924, 193 in 1925, 336 in 
1926, 246 in 1927, and 378 in 1928. Thus it can be seen that sufficient time had 
elapsed for these fish to have emigrated to other regions if they had so desired. 
