654 
BULLETIN OF THE BUREAU OF FISHERIES 
Depth 
Station 
10499 
Prince 
station 3, 
Jan. 3, 
1917‘ 
Surface _ 
°C. 
5.56 
2 6. 00 
6.03 
2 6. 80 
°C. 
3. 69 
4. 56 
5. 30 
4.59 
60 meters ... . ... ... _ 
1 From Mavor, 1923. 2 Approximate. 
Apparently the waters along the western shores of Nova Scotia are about as cold 
as the inner part of Massachusetts Bay in the first week in January, judging from 
1921, when the temperature was uniformly 3.8° to 3.9°, surface to bottom, a few miles 
off Yarmouth (station 10501) on the 4th; or about the same at the surface as the 
reading off the mouth of Boston Harbor 5 days previous, with no wider difference at 
20 to 40 meters than can be accounted for by more active vertical circulation and 
by this difference in date. 
In the northeastern part of the trough, on January 5 (station 10502), the surface 
was coldest (5.56°) overlying a uniform stratum (6.6° to 6.7°) at 40 to 100 meters, 
with slightly warmer water (6.9° to 7.2°) at still greater depths; but readings taken 
in the western side of the basin for January 9 showed the water about 2° warmer 
at 100 to 150 meters than either the surface or the bottom (station 10503). 
Thus, the level that is coldest in the western side of the basin in summer is 
warmest in midwinter — about 2.5° warmer, in fact (7.5° to 7.8°), than we have ever 
found it in August. A serial for late November is required for a correct picture of 
the autumnal change there; but the fact that the salinity of the 100-meter level was 
higher at this locality in December, 1920, than we have ever found it in August, 
September, or October (fig. 138), suggests that the temperature of its warm stratum 
had been maintained at about the November value (about 8°) throughout December 
by additions of warmer and more saline water from the southeastern part of the gulf, 
while the surface stratum had cooled. This reconstruction is corroborated, also, by 
the fact that while the surface continued to chill (about 0.5°) during the interval 
between December 29 (station 10490) and January 9 (station 10503), the 100-meter 
level warmed by about 0.5°, the 150-meter temperature rose by about 1.5° during 
the interval, with no corresponding increase in salinity (p. 994). 
In horizontal projection the midwinter serials just discussed show the 40-meter 
level coldest (3.86°) in the eastern side of the gulf, off Yarmouth, Nova Scotia; 4° 
to 6° in Massachusetts Bay, along the coast of Maine east of Penobscot Bay, and at 
the mouth of the Bay of Fundy; 6° to 7° elsewhere (fig. 80). The temperature 
was regionally as uniform at 100 meters, also, varying only from 6.03° to 7.81° over 
the whole area — coldest in the mouth of the Bay of Fundy. At 200 meters, how- 
ever, the regional distribution of temperature (also of salinity — p. 804), was just the 
reverse, being warmest (6.9° to 7°) in the northeastern branch of the basin and the 
Bay of Fundy and coldest in the western side of the basin off Cape Ann (5.3° to 5.6°) . 
No serial temperatures have been taken in the open basin of the gulf during the 
last half of January or the first three weeks of February, but records for the vicinity 
