738 



BULLETIN OF THE BUEEAU OF FISHERIES 



slope above the 100-meter contour within the gulf; seldom, if ever, above the 200- 

 meter level in its western side. The extensive, plateaulike elevation of the bottom 

 in the offing of Penobscot Bay, intermediate in depth between these two levels, like- 

 wise rises above this highly saline bottom water, although the latter approaches 

 closer than tlais to the surface in the eastern side of the gulf. 



In 1920 the inflowing bottom current slackened at least as early as the first part 

 of April, allowing the horizontal equalization of the water of the basin, just described, 



4J + 



FIG. 116.— Salinity at a depth of 100 meters, April 6 to 20, 1920 



and its vertical equalization on Browns Bank; but the general anticlockwise circu- 

 lation of the gulf continued to carry the more saline water around the basin, thus 

 increasing the salinity of its western side and lessening the regional variations of 

 salinity. On the other hand, the southern side of the Gulf of Maine eddy brought 

 water of comparatively low salinity out of the basin, to the eastern part of Georges 

 Bank, and to that side of the Eastern Channel, in the mid-depths. This probably 

 represents the normal course of events, though no doubt the seasonal schedule falls 

 earlier in some years, later in others. 



