MIGRATIONS OF COD 
75 
Table 30 . — Bottom water temperatures from west of Nantucket Shoals — Continued 
[All positions listed are true positions. The letters before the station numbers are to be interpreted as follows: A = Albatross II\ 
Q = Orampus; and H = Halcyon] 
Refer- 
Depth 
Temperature 
ence 
No. 
Station 
Date 
Position 
Locality 
Meters 
Fath- 
oms 
° C. 
o y. 
Off New Jersey — Continued 
66 
G 10377 
Aug. 10,1916 
38 54 N. 
74 44 W. 
11 miles E. by S. from Cape May Light _ 
15 
8 
15.8 
60.4 
67 
G 10379 
Aug. 11,1916 
38 46 N. 
74 35 W. 
21 miles ESE. from Cape May Light ... 
25 
13 
10.9 
51.6 
68 
G 10375 
Aug. 4, 1916 
38 59 N. 
74 08 W. 
40 miles E. J4> N. from Cape May Light . 
40 
22 
6.2 
43. 1 
69 
G 10373 
do 
38 57 N. 
73 35 W. 
66 miles E. from Cape May Light... 
South of New Jersey 
60 
32 
4.5 
40. 1 
70 
A 20407 
Mar. 3, 1929 
37 58 N. 
75 02 W. 
15 miles E. by N. from Assateague Light 
15 
8 
3.4 
38. 1 
71 
A 20408 
do 
37 47 N. 
74 40 W. 
35 miles E. by S. from Assateague Light. 
40 
22 
5.7 
42.2 
72 
A 20412 
do 
36 52 N. 
75 20 W. 
33 miles E. % S. from Cape Henry Light 
20 
11 
5.0 
41.0 
73 
A 20411 
do 
36 49 N. 
75 00 W. 
49 miles E. % S. from Cape Henry Light. 
30 
16 
7.2 
45.0 
74 
A 20410 
do 
36 45 N. 
74 36 W. 
70 miles E. by S. from Cape Henry Light. _. 
180 
98 
9.6 
49.4 
Combined with what we know of this migration from other sources such as 
fishing, tagged fish, etc., these temperatures may be interpreted as follows: 
When the first schools of cod migrate westward from Nantucket Shoals the latter 
half of October they leave behind them temperatures ranging from about 9° to 13° 
C. (48° to 55° F.) and enter a region that is somewhat warmer. In this region 
immediately to the westward of the shoals, off Marthas Vineyard and Rhode Island, 
temperatures the end of October (reference numbers 14 to 19, Table 30) in 18 to 80 
meters out to about 50 miles from shore have ranged from 11.7° to 14.5° C. (53° to 
58° F.). At this time the warmer water is found near shore, but many of the fish 
take this route, judging from the number that are caught within a few miles of shore 
late in October. By November, when the migration of cod is in full swing, the bottom 
temperatures are very much the same near shore as they are further off. Appa- 
rently the cooling of the water in the fall plays an important part in bringing about 
the migration, and even though the earliest fall migrants which leave in October enter 
a region slightly warmer than Nantucket Shoals at the time, the temperatures are not 
so high that they afford a barrier to a movement of cod farther to the westward. 
The fall migrants continue their journey, therefore, with the water becoming cooler 
and cooler as the season advances. They do not, however, keep pace with the 
temperature but migrate rapidly and appear off New Jersey only about a week after 
they pass Rhode Island. 
In the late winter the shore waters west of Nantucket Shoals are much cooler 
than the offshore (reference numbers 21 to 29, 52 to 56, 70 to 74, Table 30), but after 
the cod reach there in the late fall most of them appear to remain localized until the 
spring. In general, the cod off the New Jersey coast may move offshore a few miles 
in the coldest part of the winter, probably to seek water that is 1° or 2° warmer, but 
there are times, as in January and February, 1928 and 1929, when good catches were 
made in the shoal water of Delaware Bay, that they remain inshore. 
The cod leave their southern wintering grounds and return north and east to 
southern Massachusetts in the spring, after the water has started to warm. By the 
