480 DEPARTMENT OF THE NATAL SERVICE 



channel, the Cansan, cuts through between Sable Island bank and Banquereau. 

 Farther to the south is the Fundian channel passing out from the Bciy of Fundy and 

 through the gulf of Maine. These three channels delimit two portions of the con- 

 tinental shelf off Nova Scotia. That to the north between the Laurentian and Cansan 

 channels includes the Banquereau, Misaine, and Cansan banks, and may be called the 

 Breton portion of the shelf, or the Breton bank, since it lies off Cape Breton island. 

 The southern part lies between the Cansan and Fundian channels and includes La 

 Have and Sable Island banks. It may be called the Scotian bank since it lies against 

 the main portion of the province of Nova Scotia. 



In the St. Lawrence gulf we have to the north of Anticosti island, the Anticostian 

 channel, and running north towards the straits of Belle Isle the Esquimau channel. 

 To the south of the Laurentian channel in the gulf is an extensive submarine plateau 

 with, for the most part, less than 30 fathoms of water covering it. Cropping up from 

 it are the Magdalen islands and Prince Edward island. This area is peculiar in its 

 biological and hydrographical characters. We have referred to it as the Lower Gulf 

 region. It might be called the Magdalen bay. 



The currents of the region have been thoroughly investigated by Dr. W. Bell 

 Dawson, and his results published in the reports of the Tidal and Current Survey of 

 Canada from 1894 to 1913, including special reports on the currents. In the gulf of 

 St. Lawrence he finds that the general circulation is in a left-handed direction and 

 chiefly confined to the deep central portions. A current enters the gulf through Cabot 

 strait off cape Ray and spreads out to the north and northeast. Part runs up the 

 Esquimau channel on the east side and returns on the west. Similarly a current runs 

 up the Anticostian channel on the north side and returns on the south, and up tlje 

 Laurentian channel between Anticosti island and the Gaspe coast on the north side 

 and returns on the south. The last of these, the Gaspe current, is very strong and 

 spreads to the southeast over the Magdalen bay, passing to either side of the Magdalen 

 islands, and finally as a single stream of constant strong character, the Cape Breton 

 current, it emerges from the gulf on the south side of Cabot strait. 



Dr. Dawson has shoiwn by density determinations that the inflowing water is more 

 saline than the outflowing and, as a result, the northern part of the gulf is constantly 

 more saline than the southern, a line of division passing from East cape, Anticosti 

 island, to the middle of Cabot strait. 



The shallower channels of the gulf show the same circulation but to only a slight 

 degree. Through the straits of Belle Isle and the Mingan channel on the north there 

 is a general inward or westward tendency, and through the Northumberland strait 

 (and perhaps also the Gut of Canso^ on the south a general outward or eastward 

 tendency. 



Outside the gulf there is a slight westward tendency on the southern coast of 

 Newfoundland and a southwestward drift along the outer coast of Nova Scotia. In the 

 gulf of Maine, Bigelow has found a general left-handed circulation, entering the gulf 

 on the north and leaving it on the south. In the Bay of Fundy there is doubtless a 

 similar circulation, although so masked by the heavy tides that Dawson has been 

 unable to determine it by current measurements. 



Farther out we have two well-known strong currents, the Polar or Labrador 

 current coming down from the north along the outer coast of Newfoundland, flooding 

 the Grand Banks and then turning to the east at their southern border; and the Gulf 

 Stream coming from the southwest along the coast of the United States and being 

 deflected to the east and south just south of the Grand Banks. 



As a basis for our knowledge of the different kinds of water occurring in the 

 region we may take the three sharply marked zones found ly TTjuvt off our eon t^ in 

 1910 (Murray and Hjort, 1912, p. 109) in his section from the Azores to Newfoundland. 

 There are the following: (1) a Northern Coastal zone (Arctic?) on the Newfoundland 



1 1 have just received from Dr. Dawson a proof sheet of a forthcoming report in which he 

 describes a preponderance of outflow to the south througli the Gut of Canso. 



