SPAWNING AND SETTING OF OLYMPIA OYSTERS 
485 
Table 28. — Number of spat caught on bags of shells planted periodically in Mud Bay during 1932 
[Counts were completed on the dike B series, and representative samples from dikes D and E were studied for comparison] 
Date planted 
Date removed 
Number 
of days 
Dike B 
Dike D 
Dike E 
Total num- 
ber of spat 
Number of 
spat daily 
Total num- 
ber of spat 
Number of 
spat daily 
Total num- 
ber of spat 
Number of 
spat daily 
July 2 
July 9 
7 
441 
63 
466 
66 
July 12 
7 
935 
134 
609 
87 
July 9 
7 
2. 521 
360 
3, 663 
623 
July 12 
July 19 
7 
8, 350 
1, 193 
7,626 
1,089 
3, 469 
496 
July 16 
July 23 
7 
5, 153 
736 
4, 034 
576 
July 19 _ . 
July 26 
7 
2, 843 
403 
2,275 
325 
7 
5, 590 
798 
July 26 
Aug. 2 
7 
7, 692 
1,099 
5, 520 
789 
6, 047 
864 
July 30 . 
7 
1,705 
243 
2,126 
304 
Aug. 2 
Aug. 9. 
7 
442 
63 
354 
61 
7 
50 
7 
Aug. 9. 
Aug. 16 
7 
269 
38 
Aug. 20 
7 
1, 238 
177 
1,391 
199 
Aug. 16 
Aug. 23 
7 
2, 992 
427 
4, 057 
579 
4,271 
610 
Aug. 20 
Aug. 27 
7 
530 
76 
1, 395 
140 
Aug. 23. 
Aug. 30 
7 
2, 463 
352 
5, 177 
739 
Aug. 27 
Sept. 3 
7 
220 
31 
Aug. 30 
7 
175 
25 
7 
320 
46 
860 
123 
7 
45 
6 
Table 29. — Number of spat caught on bags of shells on 2 grounds in Mud Bay, 1933 
[Dike B is more favorable seed ground, although the time of most profuse setting is the same on both beds] 
Date 
planted 
Date re- 
moved 
Num- 
ber of 
days 
Dike B 
Dike E 
Date 
planted 
Date re- 
moved 
Num- 
ber of 
days 
Dike B 
Dike E 
Total 
number 
of spat 
Num- 
ber of 
spat 
daily 
Total 
number 
of spat 
Number 
of spat 
daily 
Total 
number 
of spat 
Num- 
ber of 
spat 
daily 
Total 
number 
of spat 
Num- 
ber of 
spat 
daily 
July 18 . 
July 25.. 
■7(1) 
1,494 
1,494 
Aug. 12. _ 
Aug. 19. 
7 
1,836 
262 
234 
33 
22.. 
29.. 
>7(5) 
2,318 
464 
157 
31 
" 15. _ 
22. 
7 
913 
130 
163 
23 
25.. 
Aug. 1. . 
7 
9, 933 
1,419 
1,417 
202 
19.. 
26. 
7 
530 
76 
55 
8 
29.. 
5.. 
7 
27, 678 
3, 954 
3, 877 
554 
22.. 
29. 
7 
226 
32 
( 2 ) 
Aug. 1.. 
8.. 
7 
10, 011 
1,430 
2, 951 
421 
26.. 
Sept. 2.. 
7 
183 
26 
( s ) 
5.. 
12. 
7 
8, 154 
1,165 
1,892 
270 
29.. 
5.. 
7 
61 
9 
M 
8 .. 
15. 
7 
1,565 
223 
463 
66 
1 Bags in water for 7 days, but setting started some time after they were planted. 
2 Only occasional spat; too few to warrant counting. 
Table 30. — Number of spat caught on bags of shells on 2 grounds in Mud Bay, 1934. 
Date 
planted 
Date 
removed 
Num- 
ber of 
days 
Dike B 
Dike E 
Date 
planted 
Date 
removed 
Num- 
ber of 
days 
Dike B 
Dike E 
Total 
number 
of spat 
Num- 
ber of 
spat 
daily 
Total 
number 
of spat 
Num- 
ber of 
spat 
daily 
Total 
number 
of spat 
Num- 
ber of 
spat 
daily 
Total 
number 
of spat 
Num- 
ber of 
spat 
daily 
June 
9 
June 16 
1 7(1) 
39 
39 
7 
7 
June 
26 
July 
3 
7 
729 
104 
137 
19 
June 
12 
June 19 
1 7(4) 
377 
94 
123 
31 
June 
30 
July 
7 
7 
1,360 
194 
355 
50 
June 
16 
June 23 
7 
2, 134 
305 
248 
35 
July 
3 
July 
10 
7 
788 
112 
85 
12 
June 
19 
June 26 
7 
1,998 
285 
343 
49 
July 
7 
July 
14 
7 
401 
67 
Juno 
23 
June 30 
7 
1, 562 
223 
266 
38 
July 
10 
July 
17 
2 7(4) 
66 
17 
1 Bags in water for 7 days, but setting started some time after they were planted. 
2 Setting stopped 4 days after planting. 
The figure shows only one period of setting, which started between July 24 and 
25, reached a maximum about a week later, then gradually declined until early in 
September when it reached the zero level. The entire length of the setting season was 
onl^y about 1 % months. Nevertheless, oyster growers obtained a highly satisfactory 
catch of seeds, for during a short time the frequency of attachment was greater than 
was found in this bay during any of the other years. 
