682 



BULLETIN OF THE BUREAU OF FISHERIES 



Sable in some summers enters the gulf about as warm as is the contribution from 

 the Cape Sable dead water (p. 835) ; actually warmer than the water with which it 

 mixes in the ofEng of Cape Sable or close by to the westward. Although icy cold 

 water persists on bottom right through the summer only a few miles east of the 

 cape, we have no evidence that anything from this source actually penetrates the 

 gulf after May. 



In short, the Nova Scotian current acts as a chilling agent in the Gulf of Maine 

 for only a few weeks during the spring, and then more to retard vernal warming 

 (p. 558) than actually to lower the temperature of the part of the gulf into which it 

 debouches below the readings prevailing there before the current commences to 

 flood past Cape Sable. During the short period of its westward flood, however, 

 and for some weeks thereafter, its chilling influence on the eastern side of the gulf is 

 obvious enough, as is described in the account of the distribution of temperature in 

 the spring (p. 553). 



We have next to consider how far the difference in temperature between the 

 side of the gulf most directly exposed to the efl'ects of the Nova Scotian current and 

 the opposite side most remote from it is recognizable at other seasons of the year. 

 This problem is complicated by regional differences in the activity of vertical 

 stirring by the tides, reflected in lower and lower surface temperatures at successive 

 stations around the shore line of the gulf from Massachusetts Bay to Nova Scotia, 

 but higher and higher temperatures at the 50 to 100 meter stratum. In order to 

 be instructive for the water mass as a whole, regional comparison must therefore be 

 based on a calculation of the mean temperature of the entire column. To name 

 one part of the gulf as potentially colder than another, or vice versa, on the 

 evidence of temperature of any one given level can only prove misleading. 



In calculating the mean temperature the gulf is best divided into two sub- 

 divisions — (1) the basin outside the 100-meter contour and (2) the shoaler water of 

 the coastwise zone. 



An earlier report (Bigelow, 1915) gives calculations of the mean temperature of 

 the stratum inclosed between the surface and the 50-fathom level for the basin, 

 which would apply closely enough to the upper 100 meters. 



Approximate mean temperature (°C.) for the upper 50 fathoms, or 100 meters, of the basin, August, 



, ■ 191S 



Locality 



Off Gloucester 



Western basin 



North of Cape Ann _.. 

 Near Isles of Shoals.. 

 Ofl Cape Elizabeths. 



Near Platts Bank 



Ofl Monhegan Island 

 Ofl Penobscot Bay.... 



Station 



100S7 

 10086 

 lOlOS 

 10104 

 10103 

 10089 

 10102 

 10101 



Mean 

 tempera- 

 ture 



7.9 

 9.7 

 8.3 

 8.4 

 9.1 

 8.3 

 9.2 

 9.4 



Locality 



Ofl Penobscot Bay 



Near Cashes Ledge 



Near central part of basin 



Ofl Mount Desert 



OQ Bay of Fundy 



Near Lurcher Shoal 



East side of basin 



Do 



station 



10091 

 10090 

 10092 

 10100 

 10097 

 10096 

 10093 

 10094 



Mean 

 tempera- 

 ture 



10.0 

 8.6 

 8.0 

 9.1 

 10.2 

 10.1 

 10.0 

 8.1 



According to this table the eastern side of the basin, with the waters along 

 the Nova Scotian slope and off the mouth of the Bay of Fundy, was potentially 

 the warmest part of the gulf (10°), not the coldest, as the popular belief that an 



