MIGRATIONS OF COD 
59 
Further evidence that Great Rip cod grow somewhat faster than Round Shoal 
cod is indicated by the Round Shoal C cod, which centered around 24 inches in Sep- 
tember, 1926, as against 26 inches for the Great Rip fish (fig. 19), and by the D cod, 
which in June, 1927, had a peak at 21 inches at Round Shoal compared with 22 
inches at Great Rip (figs. 20 No. 1, and 22 No. 2). We are justified, therefore, in 
considering the 19 to 21 inch Great Rip cod and the 17 to 19 inch Round Shoal fish 
as parts of the same group (D cod, fig. 19). 
During 1926, therefore, the stocks of cod at Great Rip and at Round Shoal 
buoy were essentially the same and had in common the following: 
1. A complete absence of small cod below 14 inches, excepting those too small 
to take the hook and concerning whose presence we have only meager information. 
2. An almost complete absence of large cod of more than 34 inches in length. 
3. Two outstanding size groups of fish — a dominant group composed of 2-year 
olds (in their third year) averaging about 18 inches long at Round Shoal buoy and 
around 20 inches long at Great Rip buoy, and a group of secondary importance, 
composed presumably mostly of 3-year olds, averaging around 24 to 25 inches at 
Round Shoal buoy and 26 inches at Great Rip buoy. The difference in size in each 
instance was due most probably to the rate of growth of the fish within their respec- 
tive areas. 
LENGTH OF NANTUCKET COD IN 1927 
The first cruise to Nantucket Shoals in 1927 was made early in May, at which 
time, 1,159 cod were caught. 
At no time since we began our cod tagging in April, 1923, did one size group 
stand out so prominently as on this cruise. (Fig. 20, No. 1.) It was apparent, too, 
that the 20-inch peak of May, 1927, and the 18-inch peak of September, 1926 (fig. 
19, No. 1), were formed by the same stock of fish, with the difference in size being- 
due to growth. 
A few scales of these 20-inch May, 1927, cod, Z), were examined and they proved 
to have three annual rings as expected in place of the two annuli plus the wide 
peripheral circuli possessed by the September, 1926, 18-inch fish. Even more positive 
proof was furnished by the scales of recaptured fish. It so happened that in May, 
1927, only one September, 1926, cod was recaptured with its tag still attached (other 
September, 1926, Nantucket Shoals cod were recaptured by us in June and Septem- 
ber, 1927). This fish, which was 19% inches long and possessed two annuli in Sep- 
tember, 1926, was 22/ inches long and had three annuli in May, 1927. 
The C cod of September, 1926, were practically out of the picture in May, 
1927, as there was then only a bare suspicion of them at 26 inches. A very few 
large cod, above 34 inches, were present in May, 1927, at Round Shoal buoy (fig. 
20, No. 1), although they were absent in 1926. They might have represented part 
of a school of cod which came from Georges Bank or elsewhere to join the cod migrat- 
ing westward toward New Jersey in the fall. But it was surprising that the stock 
of cod in May, 1927, was so nearly like that of September, 1926 — the only changes 
of note being the disappearance of the C cod and appearance of a few large fish. 
At Great Rip buoy only 93 cod were caught in May, 1927, the small catch being 
due to weather conditions and other factors rather than to a scarcity of fish. Ordi- 
narily so few fish would be insufficient upon which to draw conclusions, but in the 
present instance we can be justified in utilizing the September, 1926, and June, 
1927, catches at Great Rip to interpret conditions there in May. (Fig. 22, No. 2.) 
