614 BULLETIN OF THE BUREAU OF FISHERIES 
Station 
Depth, 
meters 
Locality 
Tempera- 
ture, ° C 
10088 
183 
Offing of Cape Ann 
6.28 
10090 
183 
6. 61 
10092 
183 
183 
219 
■ 
6. 11 
10100 
6.22 
10093 
5.89 
In August, 1914, however, the bottom water was appreciably warmer (7° to 
7.9°) in the eastern and northeastern parts of the basin than in the western and 
central parts (6° to 6.24°), apparently banking up against the Nova Scotian slope, 
as indicated on the chart (fig. 57). Successive stations, from the offing of Cape 
Ann to the Nova Scotian slope, again showed a slight rise in the temperature of the 
of the bottom water (at 175 meters) from west to east across the basin on August 
31 to September 2, 1915, as follows: Station 10307, 5.4°; station 10309, 5.8°; and 
station 10310, 6.8°. The amount by which the temperature of the one side of the 
gulf differs from that of the other, in this stratum, varies so widely from year to 
year that it would not be surprising to find it virtually uniform over the whole area 
of the basin in some future summer. 
Other features of the temperature at 175 meters worth mention are its con- 
stancy in the southwestern part of the basin from July 19 (station 10214, about 5.4°) 
to August 23 (station 10256, 5.6°) in 1914, and the fact that the southeastern part 
was warmer than the Eastern Channel in that summer , 34 although the latter offers 
the only route by which water of high temperature can flow into the gulf from off- 
shore. Barring the possibility of higher temperature in one or the other sides of the 
channel than in its center, where the observations were taken, the most reasonable 
explanation for this apparent anomaly is that a considerable indraft had taken place 
late in June, but that this had then slackened, allowing the temperature of the 
channel to be reduced slightly by mixture with the cooler water to the east and 
west of it. 
Our data for 1914, combined with temperatures taken south of Marthas 
Vineyard by Libbey (1891) in 1889, show the water along the continental edge 
abreast of the gulf as 10° to 11° at the 175-meter level in late summer, warming to 12° 
a few miles farther offshore (fig. 57). In 1914 the mouth of the Eastern Channel 
marked a division at this and greater depths between these comparatively high 
temperatures to the west and lower temperatures to the east, with the isotherms 
swinging offshore, abreast of Browns Bank, and a 175-meter value of only about 
7.7° in the offing of Shelburne on July 28 (station 10233). But with the tempera- 
ture between 11.3° and 11.85° there at this same level and at about the same date 
a year later (Bjerkan, 1919, p. 393; Acadia station 41), the ocean water was 
evidently closer in to the slope — annual variation sufficient to exercise considerable 
biologic effect on the bottom fauna along the southeastern slopes of Browns Bank 
and Georges Bank. 
Only a small portion of the basin of the gulf is deeper than 175 meters. The 
bottom of the western bowl, at 260 meters (entirely inclosed at this level), was 7° 
in August, 1914, that of the eastern branch ranging from about 6° in its western 
** Station 10225 about 8.8° and station 10227 about 7.1° at 175 meters on July 23 and 24, 1914. 
