RESULTS 
Oyster Experiments 
Mortality over the period was low (see Table 3). The only 
station showing mortality noticeably higher than that of the 
control station is Station 10. This is the most upriver station 
and subjectively seemed initially to have lower concentrations 
of fouling organisms and more silt. The single event of six 
dying, between 2 June and 14 June, may be related to heavy runoff 
and smothering by silt. 
TABLE 3. MORTALITY OF OYSTERS DURING THIS STUDY 
Station 
2 
3 
4 
5 
6 
7 
8 
9 
10 
Control 
23 May 
0 
0 
0 
* 
0 
* 
0 
0 
0 
2 
2 June 
1 
0 
0 
* 
* 
* 
1 
0 
1 
1 
14 June 
* 
0 
0 
0 
0 
0 
1 
0 
6 
0 
27 June 
0 
1 
0 
It 
1 
0 
0 
* 
★ 
0 
12 July 
* 
0 
0 
0 
1 
°$ 
0 
0 
0 
5 August 
* 
0 
1 
1 
1 
1 
1 
1 
0 
Total 
1 
1 
1 
2 
2 
3 
1 
8 
3 
★ 
Trays 
were 
not 
examined 
• 
+ Lines 
cut 
and 
tray 
missing. 
| Tampered with but appeared intact 
In late spring and early summer, growth was mostly not 
significantly different from that shown at the control station, 
and there was no pattern of either increased or decreased growth 
(see Table 4). In July, all stations showed significantly slower 
growth than the controls while in August four out of seven sta¬ 
tions showed significantly slower growth. 
24 
