90 
BULLETIN OF THE BUREAU OF FISHERIES 
The coast of Maine from the Bay of Fundy to Cape Elizabeth. — For this long 
stretch of coast it is difficult to set an average time and place for the spawning of 
the cod or an average temperature. Cod eggs spawned there in March would hatch 
in about 25 to 31 days in the 1° to 2° C. temperatures prevailing, 16 to 19 days in 
4° to 5° C. water in April, and 11 to 14 days in 6° to 8° C. water in May. The dis- 
tance from this region to Nantucket Shoals, over the shortest route that can be taken 
by the dominant drift, is about 180 to 360 miles. Arbitrarily assuming an average 
drift rate of 3 miles per day, it would require 60 to 120 days for flotsam to cover the 
distance from this region to the shoals. Allowing an incubation period of 12 to 28 
days for the eggs and a pelagic existence of about 50 days for the larvae and fry, they 
would travel 62 to 78 days before the latter reached the stage when they seek bottom. 
This region, therefore, constitutes one of the most probable sources of the cod 
fry found on bottom on Nantucket Shoals. 
Cape Elizabeth to Cape Ann.— Eggs spawned in this region in January, drifting 
southward and around Cape Cod, would incubate in a temperature averaging around 
3° C., while in February and March it would be closer to 2° C. During the principal 
part of the spawning season, therefore, hatching would there require about 23 to 28 
daj 7 s. The center of this region is about 150 miles distant from the shoals, along the 
probable route of the drift, which at an average velocity of 3 miles a day would carry 
flotsam to Nantucket Shoals in about 50 days. Allowing 73 to 78 days of drift for 
the eggs, larvae, and fry, it appears that most of the latter would pass well beyond 
the shoals before seeking bottom and, consequently, that this region is less favorably 
situated than the preceding with respect to stocking the shoals with cod fry. 
Massachusetts Bay region. — Cod eggs spawned here as early as November would 
hatch in about 10 days in 9° C. water, while in December the period would be 14 to 
19 days, for the temperature then ranges from 4° to 6° C. In January and February, 
when much of the spawning occurs in this region, the temperatures along the route 
to Nantucket Shoals average about 2° C.; hence the incubation period occupies 25 
to 28 days. The distance from both the Plymouth grounds and Stellwagen Bank 
to Nantucket Shoals is about 80 miles, and the time required for flotsam to accom- 
plish the drift at 3 miles per day would be about 27 days. From the time the eggs are 
spawned there cod fry would drift about 60 to 75 days before taking to the bottom, 
by which time those which passed over the shoals would probably go far beyond. It 
seems clear that this region is much less favorably located than others farther north 
for supplying the shoals with cod fry. 
These estimates, rough at the best, are meant to apply to the principal spawning 
grounds along the western part of the Gulf of Maine, to the height of the spawning 
period, and to the approximate velocity of the dominant drift along a direct course. 
For example, spawning on most of the grounds progresses throughout the winter, 
so that while as many eggs, or more, may be deposited during one or two months (when 
the season is at its height) as during the rest of the season combined, the secondary 
period, in the aggregate is very important. And it is possible that fry may at such 
times reach the shoals from grounds that do not contribute to the former at the height 
of the breeding season. 
Although many cod fry are carried past Nantucket Shoals by the dominant drift, 
the probability must not be overlooked that some of these seek bottom near by and 
thus are an important factor in keeping up the stock of cod off southern New England 
in general, if not on Nantucket Shoals in particular. 
