88 
BULLETIN OF THE BUKEAU OF FISHERIES 
Zooplankton volumes, mouth of Massachusetts Bay 
Date 
Station 
Depth 
of haul 
in meters 
Approxi- 
mate 
volume, 
cubic 
centi- 
meters 
per 
square 
meter 
Date 
Station 
Depth 
of haul 
in meters 
Approxi- 
mate 
volume, 
cubic 
centi- 
meters 
per 
square 
meter 
July 10, 1912 
10002 
119-0 
250 
Aug. 31, 1915 
10306 
140-0 
110 
July 19, 1916 
10340 
45-0 
125 
Octf. 1, 1915 
10324 
140-0 
150 
Do. 
10341 
80-0 
250 
Oct. 27, 1915 
10338 
80-0 
250 
Do 
10342 
55-0 
250 
Mar. 1,' 1920 
20050 
150-0 
±25 
Aug. 9, 1913. 
10087 
128-0 
180 
Apr. 9, 1920 
20090 
120-0 
10 
Aug. 22, 1914 
10253 
140-0 
60 
May 4, 1915 
10266 
125-0 
270 
Evidence that a similar augmentation spread generally throughout the coastal 
waters west of Penobscot Bay in 1915 is afforded by volumes as great as 100 to 150 
cubic centimeters per square meter off Penobscot Bay, off Cape Elizabeth, and near 
the Isles of Shoals during that October. However, we have yet to learn whether 
this increase is an annual event, nor does our experience suggest that it extends east 
of Penobscot Bay, because vertical hauls yielded only 30 cubic centimeters per square 
meter off Mount Desert Island and 20 cubic centimeters off Machias on October 9 
(stations 10328 and 10327). 
We have made no quantitative hauls in the gulf during the period between Octo- 
ber and late February, but the comparative scantiness of the yields of the horizontal 
nets in Massachusetts Bay during the cold months of 1913 (Bigelow, 1914a) and at 
all our inshore stations from Cape Cod to Yarmouth, Nova Scotia, in December, 
1920, and January, 1921, points to an ebbing zooplankton as characteristic of the 
coastal belt in late autumn and early winter, leading progressively to the extremely 
barren state of the water typical of the first weeks of spring (p. 82). Hauls made 
near Mount Desert Island and in the northeast corner of the gulf from January 1 
to 5, 1921 (stations 10497, 10500, and 10502) were equally unproductive, 42 but I 
hesitate to conclude from this that the water was actually so barren there, because 
horizontal hauls were hardly more productive in that general region in March, 1920, 
although the vertical nets yielded large catches, a fact suggesting that the former 
missed the level at which the plankton was most concentrated. However this 
may be, it seems that in winter and early spring the zooplankton is far more plentiful 
in the western side of the basin than near shore, because we made a rich horizontal 
catch there on December 29, 1920 (station 10490), a rich vertical haul (though a 
rather scanty horizontal) on February 23, 1920 (station 20049), and a rich horizontal 
and a comparatively rich vertical on March 24 of that year (station 20087). 
The results of both vertical and horizontal hauls point to the Massachusetts 
Bay region and the neighboring part of the basin, on the one hand, and to the deeps 
off Lurcher Shoal and the eastern part of Georges Bank, on the other, as the parts of 
the gulf uniformly most productive of zooplankton; while the deep water in the 
i! Yield of half an hour’s haul with a J^-meter net was only about 100 to 150 cubic centimeters in each case at 50-0, 75-0, and 
150-0 meters. 
