484 
BULLETIN OF THE BUREAU OF FISHERIES 
SEASON OF 1931 
Bags of shells were planted and removed periodically for spat counting on two 
grounds. Dike B is near the shore and dike D is next to the small channel which 
remains at low tide (see chart, fig. 4). As in Oyster Bay during this year a system 
of planting shells for regular in- 
1 
a 
DIKE 0 
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OIKE & 
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JUNE JULY 
AUGUST 
SEPTEMBER 
OCT. 
Figure 2S.— Average number of spat caught daily per bag of shells left in 
dikes B and D (Mud Bay) for different periods during 1931. 
tervals was not employed and the 
results are not as accurate as in 
later seasons. Setting began on 
the 16th of June and the maximum 
was reached at the end of the 
month, after which it diminished 
gradually in intensity (see table 27, 
fig. 28). From soon after the mid- 
dle of July until early in August 
no spat were caught, but after this 
time a few were found on every 
The total number of seeds caught was small 
The first setting period was 
bag of shells until the end of September 
as compared with Oyster Bay during the same season, 
by far the more important, as shown in the figure, while in Oyster Bay the later 
period of setting was more signifi- 
cant. All tests in Mud Bay were 
made in dikes A, B, C, D (J. J. 
Brenner Oyster Co.) and E (Charles 
Brenner). 
SEASON OF 1932 
Figure 29.— Average number of spat caught daily per bag of shells in dike 
B, Mud Bay, 1932. 
During this year the improved 
method of sampling was employed 
and complete counts were made on 
the shells tested in dike B. For comparison, some counts were made on shells planted 
in dikes D and E. The latter is across the channel from dike D. The original results 
are given in table 28, and the dike B values are represented graphically in figure 29. 
The picture is in some respects different from that ob- 
tained during 1931, but the 2 years are alike in that 
there were two separate setting periods. In the graph 
the first period falls into two maxima. The late set- 
ting, though not as intense, was sufficient to be of com- 
mercial importance, although it continued only until 
early in September. 
SEASON OF 1933 
The results for this year are given in table 29 and 
figure 30, and consist of complete counts on two series 
of bags of shells. The graphs are very similar save that 
the number of spat caught in dike E is only a small frac- 
tion of that obtained in dike B. It was necessary to dou- 
ble the scale in plotting the results in the former case in 
order to make the values distinct. It has generally been found that the catch of seeds 
Figure 30.— Average number of spat caught 
daily per bag of shells in dikes B and E, 
Mud Bay, 1933. 
in dike E and grounds nearby is much less than in other places a short distance away. 
