84 
BULLETIN OF THE BUREAU OF FISHERIES 
found swarming there in 1912, 1913, and 1914 (p. 19) . 40 While 1914 is the only 
summer for which we have quantitative data from the offshore banks, all the most 
productive (100 + cubic centimeters) of the summer hauls of 1913, 1914, 1915, and 
1916 41 were likewise similarly concentrated in the Cape Cod-Bay of Fundy belt 
just outlined (fig. 38). So uniformly productive has this "rich zone” proved in 
summer that only 3 of the 25 vertical hauls, which we have made there in June, 
July, and August, have failed to yield upwards of 100 cubic centimeters of animal 
plankton per square meter, although the waters both immediately to the north and 
to the south of it have often proved decidedly barren, as the chart illustrates. 
The average volume of plankton for all the vertical summer hauls in this rich zone 
has been nearly 170 cubic centimeters per square meter including those for 1916 
(an exceptionally rich year), and more than 150 cubic centimeters if the 1916 hauls 
are omitted. 
Approximate volume of plankton per square meter of sea surface. July and August hauls, 1912 to 1916 
Year 
Station 
Volume 
in cubic 
centi- 
meters 
Depth 
Year 
Station 
Volume 
in cubic 
centi- 
meters 
Depth 
Meters 
Meters 
1912 
10002 
250 
119 
1914 
10213 
210 
110 
10004 
50 
55 
10214 
120 
175 
10007 
65 
265 
10215 
60 
70 
10008 
50 
41 
10216 
30 
70 
10011 
20 
110 
10218 
50 
500 
10015 
10 
37 
10223 
170 
75 
10021 
10 
110 
10224 
240 
55 
10022 
30 
82 
10225 
30 
260 
10025 
80 
91 
10226 
200 
85 
10027 
30 
165 
10227 
50 
220 
10031 
30 
128 
10229 
170 
100 
10035 
Trace. 
73 
10230 
140 
50 
10036 
30 
165 
10243 
100 
55 
10038 
20 
73 
10244 
15 
50 
10043 
15 
165 
10245 
60 
110 
10246 
200 
190 
Fathoms 
10247 
10 
30 
1913 
10087 
180 
128 
10248 
100 
190 
10089 
80 
183 
10249 
105 
220 
10090 
120 
164 
10250 
350 
145 
10092 
160 
219 
10253 
60 
140 
10095 
60 
37 
10254 
200 
260 
10096 
120 
91 
10255 
70 
175 
10098 
70 
55 
1915 1 
10304 
275 
200 
10099 
30 
37 
10306 
110 
140 
10100 
220 
165 
10307 
165 
235 
10101 
100 
73 
1916 
10340 
125 
45 
10102 
90 
128 
10341 
250 
80 
10103 
70 
73 
10342 
250 
55 
10104 
90 
146 
10344 
225 
80 
10105 
55 
110 
10345 
200 
150 
* 
10346 
200 
62 
1 For a list of the hauls for other months of this year see Bigelow, 1917, p. 314. 
Contrasting with the rich belt, the entire coastal zone of the gulf, from Cape 
Ann on the south and west to Grand Manan Island at the mouth of the Bay of 
Fundy on the east and north, has invariably proved far less productive of zooplankton 
in midsummer — never with more than 90 cubic centimeters per square meter, usually 
40 These ctenophores had shrunk in the preservative to only a fraction of their natural bulk before the vertical hauls were 
measured. 
41 In 1916 the zooplankton was unusually abundant in the waters off Cape Cod and in the southwest corner of the gulf in 
July, a fact discussed on p. 97. 
