BIOLOGICAL STUDY OF CHESAPEAKE BAY WATERS 
295 
A similar condition may be seen for the salinity values at the 30-meter depth. 
The single determination at 30 meters during the March cruise was 16.50, while 
those of the July and October cruises (1920) were higher and those of the January, 
1921, cruise lower. 
Table 6. — -Surface and 30-meter salinities at area L, taken at frequent intervals during 2f hours, July 
and October , 1920, and January, 1921 
Period 
Sur- 
face 
30 
me- 
ters 
Period 
Sur- 
face 
30 
me- 
ters 
Period 
Sur- 
face 
30 
me- 
ters 
Period 
Sur- 
face 
30 
me- 
ters 
Jnl!/ 6-7, 1920 
July 6-7, 1920 — 
Oct. 18-19, 1920— 
Jan. 26-26, 1921 
10.19 a. m 
12. 50 
20.20 
Continued 
Continued 
10.30 a. m . ...... 
13. 64 
16.80 
12. 56 
20. 04 
12. 76 
19. 18 
9.00 p. m 
15. 92 
21.93 
13. 64 
15. 34 
1.19 p. m 
12. 57 
19. 98 
5.49 a. in 
12. 40 
20. 01 
10.30 ji. in. ... 
15. 85 
21. 92 
1.30 p. m 
13. 97 
16. 12 
2.49 p. in 
12.53 
20. 10 
Midnight 
15. 38 
22. 04 
3.00 p. m 
14. 15 
14. 87 
12. 60 
20. 00 
Oct. 18-19, 1920 
1 . 30 a. m 
15. 79 
21. 88 
4.30 p.m.. __ 
14. 52 
14. 87 
5.49 p. m 
12. 08 
20. 10 
10.30 a. in 
15. 90 
22. 30 
3.00 a. m 
15. 77 
21. 82 
7.35 p. m 
14. 26 
14. 64 
7.19 p. ill 
12.68 
20. 04 
Noon 
15. 89 
22. 24 
4.30 a. ni 
15. 68 
21. 75 
3.00 a. in. . ... 
14. 59 
14. 59 
8.49 p. ill. . 
12. 66 
20. 00 
1.30 p. m ... 
15. 90 
22.34 
6.00 a. m 
15. 76 
21. 61 
4.30 a. m 
14. 38 
14. 87 
10.19 p. m. 
12. 58 
19.68 
3.00 p. m 
15. 86 
22. 32 
7.30 a. in 
15. 71 
21. 99 
9.00 a. in 
14. 20 
14. 34 
11.49 p. m 
12.68 
19. 69 
4.30 p. in 
15. 95 
22. 22 
9.00 a. in 
15. 81 
21. 87 
1.19 a. in. 
12.68 
20. 06 
6.00 p. m 
15.98 
21. 35 
2.49 a. m 
12. 73 
20. 02 
7.30 p. m 
15. 92 
21. 85 
RELATION OF SEASONAL SALINITY TO SALINITY OF COASTAL WATER 
The investigations of H. B. Bigelow (1917b) along the eastern coast of the United 
States in the region of Chesapeake Bay indicate that “the salinity of the coast water, 
so far as is known, rises during autumn and winter * * *”. Water samples col- 
lected outside of the mouth of Chesapeake Bay on January 20, 1914, and January 27, 
1916, at the depth of 18 meters showed that the salinity was 33.57 and 33.35, respec- 
tively. (See Bigelow, 1917b, pp. 54, 55,60; and 1922, pp. 124, 181, 184.) While no 
water sample was collected below the surface at this same station in November, 1916, 
other data indicate that the salinity at 18 meters was about 33.00; at the surface in 
this same locality the salinity was 32.52. On the other hand, the salinity at 18 
meters on August 21, 1916, was 31.02. These data, which were the ones directly 
concerned with Chesapeake Bay in Bigelow’s study, indicate a. higher degree of salin- 
ity for the coastal water in the winter than in the summer. 
The salinity determinations inside of Chesapeake Bay are, on the whole, in ac- 
cord with Bigelow’s tentative statement concerning the rising of the salinity of the 
coastal water during autumn and winter. 
SALINITY AT 30 METERS AND AVERAGES OF SALINITIES 
The data that we have for salinities at 30-meter depths, although limited, sup- 
port the view that the coastal water increases in salinity during the latter part of the 
year after the floods of the first part of the year. At area A, off Cape Charles City, 
the salinities at 30 meters on the following 1920 cruises were: March, 20.81 ; August, 
'28.09; and October, 27.02. Near the middle of the bay at area L during the same 
year and at the same depth they were as follows: March, 16.15; July, 20.26; August, 
19.76; October, 22.24; and December, 20.10. Farther up the bay at area R the 
data at 30 meters for two cruises during 1920, were: March, 16.06; and December, 
19.68. No samples were collected at 30 meters during the January cruise. 
Those areas visited during 1920 also show higher surface salinities during the 
cruises of the latter part of the year. The following are examples: Area G, January, 
*28.19; March, 20.64; May, 19.26; July, 20.54; August, 22.73; October, 20.28; and 
December, 25.20. Area A, January, 23.32; March, 18.70; July, 21.72; August, 
