814 



BULLETIN OF THE BUREAU OF FISHERIES 



of surface salinity is only about one-fourth as wide (about 1 per mille) as in the Bay 

 of Fundy — half as wide as at the mouth of Massachussetts Bay. The surface off 

 Mount Desert then salts again slowly right through the summer and early autumn, 

 its salinity increasing from about 31.5 per mille on May 11, 1915 (station 10275), to 

 to 32.66 per mille on October 9 (station 10328); and while we lack data for No- 

 vember and December it is probable that the surface is near its saltest here during 

 the late autumn and early winter, for readings for January 1, 1921, and March 3. 

 1920, were somewhat lower and almost precisely alike (32.3 and 32.2 per mille). 



The seasonal fluctuation associated with land drainage is strictly confined to 

 the superficial stratum off this open coast, probably because the more saline water 

 in the trough of the gulf tends to bank up along this part of the coastal slope here 

 at all times of year. Thus the highest and the lowest salinities yet recorded at the 

 40-meter level near Mount Desert are only about 0.4 per mille apart (32.16 per mille, 

 July 19, 1915, station 10302, and 32.6 per mille, August 13, 1913, station 10099). 

 About the same range and the same maximum and minimum values were recorded 

 near bottom at 80 meters, though the water at this depth proved most saline in 

 January (station 10497, January 1, 1921, 32.6 per mille); least so in May (station 

 10274, May 10, 1915, 32.23 per mille) . 



GERMAN BANK 



The seasonal cycle on German Bank appears from the following summary: 



Date 



Date 



Station 



Salinity 

 at the 

 surface 



Salinity 

 at 40 

 meters 



Mar. 23, 1920 

 Apr. 15, 1920. 

 Apr. 28, 1919. 

 May 7, 1915 . 

 May 30, 1919. 

 June 19, 1916. 



Aug. 14, 1912, 



Aug. 12, 1913. 

 Aug. 12, 1914. 

 Sept. 2, 1915. 



10029 

 10030 

 10095 

 10244 

 10311 



FeT mille 



32.75 

 32.84 

 32.23 



Per mille 



32.80 



32.97 

 32. 90± 

 32.60 



1 Probably. 



' Ice Patrol station. 



A seasonal variation of at least 1 per mille is thus to be expected there, with 

 the whole column of water least saline sometime between the last of April and first 

 of June, the exact date depending on the flow and ebb of the Nova Scotian current. 

 Data for this part of the gulf during autunm and winter are desiderata. 



WESTERN SIDE OF THE BASIN 



The extent to which the salinity of the basin of the gulf is afi^ected by the out- 

 rush of river water in spring depends more on the tracks of the latter than on the 

 distance ofl^shore. Consequently, the considerable variations that have been re- 

 corded in the salinity of the surface of the basin in the offing of Cape Ann from summer 

 to summer no doubt reflect corresponding variations in the volume and direction 

 of the drift from the north past Cape Ann. 



In the summers of 1912 and 1914 this di'ift appears to have been turned sharply 

 offshore by the jutting cape, so that the surface water of the neighboring parts of 

 the basin was about 1 per mille less saline in July and August than the mean value 



