722 
BULLETIN OF THE BUREAU OF FISHERIES 
in spite of the very considerable area covered by the stations and the variation in 
depth from 50 to 90 meters. 
The contrast between this low bottom salinity on Georges Bank and the more 
saline water that then bathed Browns Bank (33.02 per mille) has already been 
commented on (p. 719). 
It is probable that wide regional variations in bottom salinity would have been 
recorded all along the shores of the gulf in March at depths less than 20 to 30 
meters, corresponding both to the precise depth and to the location relative to the 
sources of land drainage, had more readings been taken so shoal, because the values 
ranged from 32.3 to 33.1 per mille at the bottom of Massachusetts Bay at depths 
of 12 to 70 meters on February 24 to 28, 1925, and from 32.4 to 33 per mille at 25 to 76 
meters on March 10 of that year, the higher values at the deeper stations, the lower 
values at the shoaler stations. In the Ipswich Bay region, however, between Cape 
Ann and the Isles of Shoals, the bottom water varied only from 32.9 to 33.2 per 
mille in depths of 30 to 64 meters on March 12, 1925 ( Fish Hawk cruise 9). 
ANNUAL VARIATIONS IN SALINITY IN MARCH 
An approximate idea of the variation in salinity that may be expected from 
year to year in the gulf at the beginning of March results from the following com- 
parison between the observations taken in its western side by the Albatross in 1920 
and at nearby locations by the Halcyon in 1921: 
Mouth of Massachu- 
setts Bay 
Near Isles of Shoals 
Off Cape Elizabeth 
Depth, meters 
Mar. 1, 1920 
Mar. 5, 1921 
Mar. 5, 1920 
Mar. 5, 1921 
Mar. 4, 1920 
Mar. 4, 1921 
20050 
10511 
20061 
10509 
20059 
10507 
0— 
32.35 
32. 64 
32.2 
32. 85 
32. 09 
32.35 
40 
32. 36 
32. 70 
32. 34 
32.79 
* 32. 20 
32. 47 
90... 
32.32 
100 
32.34 
32. 76 
32.41 
32. 86 
32.47 
150 
32.39 
32.70 
175 
32.91 
32.99 
Off Seguin Island 
Western Basin 
Depth, meters 
Mar. 4, 1920 
Mar. 4, 1921 
Feb. 23, 1920 
Mar. 24,1920 
Mar. 5, 1921 
20058 
10508 
20049 
20087 
10510 
0 
31. 31 
32. 32 
32.52 
32. 49 
32. 49 
15 
32.00 
32. 30 
30 
32.30 
40 
32.54 
32.47 
45 . 
32. 34 
50 
32. 52 
60 
32.41 
100 
32. 54 
32. 63 
32.65 
150 
33.40 
33. 53 
33. 12 
200 
33. 78 
34.05 
225 
33.08 
250 
34.22 
33.99 
1 Approximately. 
These tables show salinities averaging about 0.4 per mille higher in 1921 than in 
1920, at depths less than 150 meters along the coastal zone from the mouth of Massa- 
chusetts Bay to the neighborhood of Cape Elizabeth; but the readings for the two 
