768 



BULLETIN OP THE BUREAU OF FISHEKIES 



again the case during August and the first few days of September in 1915 (fig. 137), 

 when the surface was less saUne than 32.5 per mille at all the eastern stations on the 

 line Cashes Bank-Cape Sable, but more saline (32.6 to 32. S per mille) farther north 

 in the eastern arm of the basin. 



Unfortunately, the stations for 1915 were not situated close enough together to 

 locate the course of the isohaline for 32.5 per mille in a satisfactory manner; in the 

 preliminary account of the operations for that season a reading of 32.52 per mille near 

 Cashes Ledge (station 10308), with slightly lower salinities to the west of it as well 

 as to the east (32.47 per mille at stations 20307 and 20309), was taken as evidence 

 of a body of still salter water in the southern half of the gulf (Bigelow, 1917, 



Fig. 137.— Salinity at tiie surface, August to September, 1915 



p. 222, fig. 67) . Further study of the salinities for the several years combined makes it 

 more probable that the station in question marked the southwestern extremity of a 

 band of 32.5 per mille that continued thence to the vicinity of Lurcher Shoal, as is 

 indicated on the chart (fig. 137). 



A pool more saline than the surrounding water and usually very close to 32.75 

 to 33 per mille in actual salinity, may thus be expected to develop annually on the 

 surface over the northeastern corner of the basin in August, its boundaries conform- 

 ing more or less closely to the contour of the coastal slopes of Maine and of Nova 

 Scotia but not involving the Bay of Fundy at all. Being entirely surroimded (in 

 most summers, at least) by less saline water oh the ofi'shore as well as on the inshore 

 side, it must obviously have its source in the still higher salinities below the surface 



