740 BULLETIN OF THE BUREAU OF FISHERIES 
ANNUAL VARIATION IN THE SALINITY OF THE BOTTOM WATER IN 
APRIL 
The station data for 1920 picture salinity in the deep trough of the Gulf of 
Maine during a spring when a very considerable volume of water enters via the 
bottom of the Eastern Channel. Probably the deep water was equally saline in April, 
1913, if not more so, when the surface of the southwestern part of the gulf and the whole 
column of water on Georges Bank were considerable salter than at the corresponding 
date in 1920 (p. 725). In 1919, however, no salinities higher than 33 per mille were 
recorded in the bottom of the basin either in March or in April (fig. 103; ice patrol 
stations 1 to 3 and 19 to 22) . This difference is partly to be explained on the assump- 
tion that the indraft into the bottom of the gulf ceases during the period (later or 
earlier in the spring in different years) when the Nova Scotian current is flooding 
into the upper strata of the gulf from the east. In part, too, the difference between 
lower salinities in the deeps of the gulf in 1919, than in 1920, can be explained by 
the fact that the one was an early and the other a tardy season. However, so wide 
