NATURAL HISTORY OF THE BAY SCALLOP 
619 
Table 9. — Extreme, monthly maximum and minimum salinities at Fivers Island, 192^-1928 
[Fractions of parts per thousand are omitted] 
Month 
Year 
Janu- 
ary 
Febru- 
ary 
March 
April 
May 
June 
July 
August 
Septem- 
ber 
Octo- 
ber 
Novem- 
ber 
Decem- 
ber 
MAXIMUM 
1924 
1925 
1926 
1927 
1928 
MINIMUM 
32 
30 
29 
31 
33 
32 
30 
32 
32 
25 
28 
32 
27 
24 
27 
30 
32 
35 
36 
35 
35 
35 
35 
33 
32 
29 
31 
33 
35 
36 
35 
38 
37 
34 
35 
34 
33 
35 
31 
34 
35 
37 
38 
38 
35 
34 
34 
34 
35 
35 
34 
35 
35 
37 
38 
38 
35 
32 
34 
37 
1924 
21 
16 
20 
18 
27 
23 
21 
21 
6 
14 
16 
23 
1925 
14 
18 
18 
15 
30 
31 
28 
24 
28 
28 
27 
27 
1926 
22 
20 
20 
21 
27 
22 
33 
34 
32 
30 
28 
27 
1927 
26 
28 
22 
25 
31 
34 
35 
30 
28 
28 
27 
20 
1928 
26 
26 
25 
27 
23 
32 
35 
35 
24 
19 
21 
23 
■X 
/jaf 
1925 
When fall towings were begun at Pivers Island in 1928, larvae believed to be 
those of the scallop were taken regularly. They soon disappeared, however. This 
might have been one of the vagaries 
of distribution or collecting but, in 
view of the failure of the “set” or 
crop of young it seems probable that 
it was due to death from the freshets 
which were responsible for a destruc- 
tion vastly more serious than that 
of adults. 
At Pivers Island, routine daily 
hydrometer readings are taken. 
Although these might readily miss 
the extreme reduction during a brief 
freshet, they would be expected to 
yield satisfactory data for a long-con- 
tinued saline reduction such as oc- 
curred in the fall of 1928. However, 
although there was definite mortality, 
presumably due to the freshet, not 
only at Pivers Island but also nearer 
the inlet, the lowest reading corres- 
ponds to a salinity of about 19 
parts per mille. (Fig. 30.) If the 
figures obtained really represent the 
lowest salinity occurring over the 
Beaufort Harbor scallop beds, it is 
indicated that salinity reductions 
below 20 parts per mille are dan- 
gerous. On the other hand the fact 
that the salinity in Newport River 
at a point where salinities of 25 to 
35 parts per mille were found before 
C 
10 
30 
10 
to 
30 
20 
10 
30 
20 
10 
30 
20 
10 
20 
10 
s' 
tsi 6 
19X7 
1929 
JAti FEB VAX APR. HAY ME MY AUG. S£PI OCT. NOV. DEC. 
Figure 32. — Monthly maximum and minimum water temperatures at 
Pivers Island, 1924-1928, based on one reading daily. (See Table 12) 
the freshet, went as low as 4.8 parts per mille would make it appear not improbable 
that salinitieg at its mouth (that is, in Beaufort Harbor) went considerably , below 
such a figure as 19 parts per mille. 
