BIGELOW: EXPLORATIONS OF THE COAST WATERS. 241 



of Georges Bank in 1914 being hard to explain, except as an outflow- 

 ing current from the Gulf. Whether, however, this is a regular, or a 

 sporacHc phenomenon, is yet to be learned. 



The seasonal cycle of temperature and salinity, (p. 205) indicates 

 the following fluctuations in the relative importance of the several 

 waters in the Gulf of Maine, from season to season. 



River water is at its minimum in February and March (1914b), 

 when the salinity, at least in the western part of the Gulf (where alone 

 it is known at that season) is at its maximum (1914b). But, as a 

 result of the freshets of early spring, it suddenly assumes great 

 importance in April, as evidenced by the sudden freshening which 

 takes place all along the coast west of Penobscot Bay (1914b), and 

 which probably includes the coastal zone east of the latter as well; 

 and local variations in salinity show (1914a, p. 91, 1914b, p. 402) 

 that there is then a distinct along-shore current from northeast to 

 southwest, the result of the successive increments of fresh water 

 added by the various rivers, which I have myself found very noticeable 

 as it flows past Cape Ann. The actual freshets are ended by May 

 (though the river flow is considerable throughout the year), when 

 salinity immediately next the land is at its minimum, (p. 213; 1914b, 

 p. 393). 



North of Cape Ann, the visible effect of the freshets hardly survives 

 its immediate cause, as evidenced by the rise in salinity which takes 

 place along the coast in June; and this is probably more or less true 

 everywhere within two or three miles of land, owing to the frequent 

 upwelling of bottom water, caused by offshore winds (1914b). But 

 river water is increasingly evident throughout the late spring and 

 early summer, off Massachusetts Bay, and over the Western Basin, 

 where the immediate effects of the freshets are less pronounced, not 

 reaching its maximum, even within 8-10 miles of Cape Ann until 

 August (p. 207, Fig. 42) ; and at least in some years, it then appears as 

 a distinct tongue extending eastward from Cape Ann (1914a, pi. 2), 

 or as a general fresh area off Massachusetts Bay (Fig. 18). Even 

 here, however, it dwindles very rapidly in importance in late summer 

 and early autumn (Fig. 42, 47). 



In the Gulf, river water is always most in evidence at and near 

 the surface, as might be expected; and it has very little effect below 

 1,00 meters, except close to land. 



So far as our data go, northern, like river water, is at its maximum 

 in the Gulf in early ^lay, when we encountered a current running 

 westward past Cape Sable into the Gulf, unmistakably identified by 



