912 BULLETIN OF THE BUEEAU OF FISHERIEfe 



more closely as far as the cape, or perhaps to Massachusetts Bay, such as were actu- 

 ally followed by bottles set out in the Bay of Fundy during the summer of 1919 

 (p. 870) and off Cape Neddick (series O) in July, 1926. The locations of the isohalines 

 at the surface are thus entirely reconcilable, both with the drifts assumed for the 

 bottles and with the annual difference indicated by the sets put out in the summers of 

 1919, 1922, 1923, and 1926. 



Mavor (1923), in his discussion of the distribution of salinities and temperatures 

 in the Bay of Fundy for August, 1919, has shown that these are best explained as 

 due to a movement of water into the bay on the Nova Scotian side, recognizable 

 from the surface down to a depth of 100 meters, crossing northward toward New 

 Brunswick about midway up the bay, with a counterbalancing outflow of water 

 of low salinity southward and westward along the northern (New Brunswick) 

 side. Here, again, temperature and salinity corroborate the evidence of drift 

 bottles (p. 870). 



The high surface salinities recorded in the northeastern corner of the gulf on the 

 August cruises of 1912 and 1913 suggested a continuous tongue of highly saline water 

 flowing into the eastern side of the gulf at the surface from the Atlantic Basin. 

 However, subsequent discovery that the high surface values encountered in the basin 

 between Maine and Nova Scotia in successive summers actually represent an isolated 

 pool, resulting from local upwelling combined with tidal stirring (p. 768), and sur- 

 rounded by less saline water on all sides, has lead to the appreciation that the gulf 

 receives its saline water chiefly in the deeper strata (p. 842), not on the surface. 



The rather abrupt west-east transition in surface salinity registered in the offing 

 of Cape Sable in the summers of 1914 and 1915, added to the retreat of the critical 

 isohalines (32 to 31.5 per miQe) from the eastern side of the gulf, eastward, with the 

 advance of the spring (p. 755), argues against any notable current from the east past 

 the cape as characteristic of summer. Here, however, the effect which the active 

 tidal mixing southwest and west of the cape would have in increasing the salinity of 

 the surface, moving westward, must be taken into account. 



If the evidence of salinity does not make clear the dominant set, if any, past 

 Cape Sable for the summer months, the tongue of low salinity and low temperature 

 found extending along the southeastern face of Georges Bank from northeast to 

 southwest in July, 1914 (p. 770), is "hard to explain, except as an outflowing current 

 from the gulf" (Bigelow, 1917, p. 241) ; and though this may not be a regular feature 

 of the summer circulation (p. 608), the fact that several bottles from the Cape Cod and 

 Cape Ann series of 1922 and 1923 seem to have drifted out of the gulf via this same 

 route across the eastern end of Georges Bank (figs. 174 and 176) is certainly sug- 

 gestive of its permanency. A tendency for water of low salinity to spread from the 

 vicinity of Cape Cod southeastward to the neighboring part of Georges Bank is also 

 indicated by the contrast in salinity between the western and eastern ends of the 

 latter on the summer chart for 1914 (fig. 136, isohaline for 32.2 per mille). Here, 

 again, a close parallel appears from the set, as indicated by the salinity of the surface 

 water and the probable drift tracks of bottles that went in that direction from the Cape 

 Cod series of 1922 (series B, p. 880, fig. 174). Fai-ther south, in the southwestern 

 part of the area, successive isohalines for 32.5 to 33.5 or 34 per mille, closely crowded 

 and roughly paralleling the edge of the continent, prove that the dominant set here 



