MIGRATIONS OF COD 
7 
by the Fish Commission schooner Grampus and by commercial fishing vessels. The 
spent fish were weighed, measured, tagged, placed in live cars, and then towed out 
into Vineyard Sound or Buzzards Bay, where they were liberated. 
The tags used in this experiment were made from sheet copper, cut in pieces 
five-sixteenths to three-fourths inch long and one-fourth inch wide, with a hole punched 
on one end. A fine copper wire was used to attach the tag to the fish. Different 
points of attachment were tried, among them the bases of the three dorsal fins, the 
two anal fins, and the upper and lower caudal lobes. Smith concluded, however 
(ibid., p. 194), that the upper part of the caudal fin near the base was the best. 
Smith found that some tags were lost by gradually tearing from the fin, but stated 
that the available evidence failed to show that many tags could have been lost in this 
manner. However, no tagged fish were taken by the tagging vessel Grampus , and 
therefore there was no opportunity in the field to check the number of fish having 
scars caused by the tag tearing loose. The fine wire used by Smith would leave 
scarcely any wound or scar after it had been lost by the fish, and no fisherman would 
have recognized a fish as having lost its tag. Without our observations in the field, 
we, like Smith, would have greatly underestimated the losses of tags. Then, too, the 
tags used by Smith were in two pieces — sheet metal and wire — therefore movable and 
more liable to loss than the rigid 1-piece tags used in the present investigation. 
Table 1.- — Numbers of cod tagged and recaptured as a result of the marking experiments made off Woods 
Hole from 1897 to 1901 
December-January-February 
Fish 
tagged 
Subse- 
quently 
recaptured 
Percentage 
recaptured 
1897-98 
35 
6 2 
1898-99 . _ . . _ . __ - 
593 
30 
5 0 
1S99-1900 
1,421 
22 
1 5 
1900-1901 
1, 443 
53 
3 7 
Total 
4, 019 
140 
3.5 
Table 2. — Summary of recaptures, by localities and months, of tagged fish released in the vicinity of 
Buzzards Bay during 1897-1901 
Recaptured 
Month released 
Locality of recapture 
During first year 
During 
second year 
Dec. 
Jan. 
Feb. 
Mar. 
Apr. 
May 
June 
July 
Aug. 
Sept. 
Nov. 
Dec. 
May 
December 
2 
3 
1 
2 
1 
1 
January 
do. _ 
1 
14 
9 
6 
4 
1 
1 
February 
. _ do. ... _. .. 
2 
1 
3 
2 
December.— . 
Marthas Vineyard and No 
Mans Land. 
do. . — _ 
2 
January . 
2 
3 
1 
February . . 
December _ 
2 
3 
1 
January 
do 
1 
2 
5 
7 
9 
2 
1 
February 
1 
2 
3 
1 
1 
December.-. ... 
Long Island. _. 
4 
3 
1 
January... 
do 
4 
5 
1 
4 
1 
February. 
2 
December 
2 
1 
2 
January... __ _ 
-..do.... 
1 
1 
1 
February 
December 
Elsewhere . . - 
1 
January 
do... . 
1 
February.. 
