198 
BULLETIN OF THE BUREAU OF FISHERIES 
would contain at least one and sometimes two or three large oily adult Calanus, 
even without the voluntary selection of such morsels which these fishes regularly 
practice, and the fish may be expected to be (and often are) packed full of this “red 
feed. ” 
At any time from early May until midsummer there exists a sufficient stock of 
Calanus, which is dense enough in some part of the gulf to afford a bountiful food 
supply. Our hauls point to the outer part of Massachusetts Bay, with the neighbor- 
ing waters along Cape Cod to the south, offshore to the east, and probably north- 
ward to Cape Elizabeth, as on the whole the subdivision of the gulf where it appears 
most abundantly during the spring and early summer, both absolutely and per cubic 
meter of water. Secondary centers of abundance have been recorded in the eastern 
basin, the northern channel, and off the southeast slope of Georges Bank, but the 
last of these was certainly transitory, (p. 193) and the others may have been equally so. 
In warm summers, when the peak of abundance for Calanus finmarchicus has 
passed before July, fewer are to be expected per cubic meter. In August, 1913, when 
the percentage of Calanus in the vertical hauls was determined by Dr. C. O. Esterly 
(Bigelow, 1915, p. 286), this copepod averaged only 244 per cubic meter at 14 stations 
generally distributed over the northern half of the gulf, even assuming that all of 
them were taken above 175 meters, the figures being as follows: 
Station 
Number 
per cubic 
meter 
Station 
Number 
per cubic 
meter 
100S7 
293 
10098 
91 
10089 
94 
10099. 
324 
10090 
229 
10100 
309 
10092 
503 
10101 . ..... 
411 
10095 
104 
10102 
176 
10096. 
330 
10103 
274 
10097 
160 
10105 
123 
The average at the Gulf of Maine stations inside the continental edge for July 
and August, 19 14, 100 was about 600 Calanus per cubic meter, varying from less than 
100 to upward of 2,000. These calculations show that in late summer most parts of 
the gulf offer by no means as fertile a feeding ground for the fishes that eat Calanus 
as it does two or three months earlier in the season. 
In the offshore parts of the gulf there is less variation in the number of Calanus 
per cubic meter of water, from station to station, in August than in May, with no 
definite contrast between "rich” and "poor” regions; but in the coastal belt the 
extremes, represented by very barren hauls between Mount Desert Island and the 
mouth of the Bay of Fundy and by upward of 2,000 at one station close to Cape Sable 
(station 10243), are perhaps as far apart as at any season. The fact that Calanus 
about tripled in number at the locality last mentioned during the interval from July 
25 (station 10230) to August 11, in 1914, shows that rapid changes take place. 
Nine vertical hauls for September, 1915, distributed over the eastern half of the 
gulf along the coast of Maine and in Massachusetts Bay give an average of approxi- 
11,0 A table of the number of copepods and large Calanus per square and per cubic meter for that year is given in an earlier report 
(Bigelow, 1917, p. 315) . The present calculation for 1914 is based on an estimated average of 70 per cent Calanus, which is probably 
below the true figure. 
