MIGRATIONS OF COD 
3 
In Europe the cod has been studied by means of marking experiments for more 
than 25 years, while in American waters, prior to the present experiment, one was 
made off Woods Hole, Mass. Although marking experiments have thrown con- 
siderable light on the behavior of the cod in European waters, particularly on their 
migrations, we can not assume that the same conditions obtain along our coast or 
that the habits of American and European cod are similar in all respects. 
The present investigation was undertaken on April 17, 1923, to study the cod’s 
life history not only as a matter of biological interest but so that if a decided decline 
in the abundance of the fish should ever occur the fishing industry would be able 
to adjust itself thereto with as full a knowledge as possible of the fish’s habits, 
especially of its migrations, duration of life, rate of growth, and size at different 
ages. The present study concerns the natural history of the cod after it seeks bot- 
tom, including fish as small as about 2 inches in length. 5 Most of the field work 
during 1923-1925 was carried out by means of the Bureau of Fisheries’ vessel Halcyon, 
commanded by G. W. Carlson. A few fish were tagged by the steamer Fish Hawk, 
while specimens and data were collected by the steamer Gannet. In 1926 the Halcyon 
and Fish Hawk were taken out of service, and since that time all investigations have 
been carried out with the Albatross II, together with small fishing boats. 
It was realized at the start of this cod investigation that an extensive territory 
was available for carrying on operations, including both the shore grounds along the 
entire New England coast and the offshore banks such as Georges, Browns, Sable 
Island, and the Grand Bank. As the Halcyon was not suitable for fishing the offshore 
banks, operations from 1923 to 1925 were restricted to within about 40 miles of land. 
Nantucket Shoals was selected for the first tagging partly for this reason, partly 
because (a) it is the most southerly region along our shores where cod are caught in 
abundance in the summer; ( b ) there was a strong probability from Smith’s (1902) 
experiment that a migration of cod occurs between Nantucket Shoals and the region 
from Rhode Island to New Jersey, so that definite results might be expected from 
the first year’s work; (c) cod are abundant in water shoal enough to fish conveniently 
with hand lines; (d) boats fish there from time to time; and (e) two of the largest 
offshore fishing banks — South Channel and Georges Bank — are adjacent, thus 
affording an opportunity for determining migrations of cod to and from Nantucket 
Shoals. 
Opportunity is taken here to thank Dr. Henry B. Bigelow, of Harvard University, 
for his helpful advice in the preparation of all parts of this paper. Thanks are also 
extended to O. E. Sette for suggestions, temperature records, and other data, and to 
R. A. Goffin for specimens of young cod. Acknowledgment is made to Capt. G. W. 
Carlson of the Halcyon, and later of the Albatross II, and to the officers of these 
vessels for their cooperation, which was so necessary in making the field work a 
success. Finally, I wish to thank fishermen and those connected with the fishing 
industry for sending tags from recaptured fish and for supplying information on the 
habits of the cod. 
HISTORICAL 
COD MIGRATIONS IN EUROPEAN WATERS 
The first real attempt to determine the migrations of cod by means of tagging 
experiments was made in the North Sea off Scotland, in October and November, 
1888, when 16 fish were marked with numbered brass labels. (Fulton, 1890, pp. 
t Some study has been given to earlier stages by Charles J. Fish: Production and Distribution of Cod Eggs in Massachusetts 
Bay in 1924 and 1925. Bulletin of the Bureau of Fisheries, Vol. XLIII, 1927 (1928), Pt. II, pp. 253-296. 
