13
Live Organisms >50 µm –
Cultured native oyster larvae (
Crassostrea virginica
)
were added to
the intake water to increase levels of live organisms >50 µm by approximately 30,000/m
3
for this
trial.
Signs of stressed organisms (slow moving and slow response to stimulus) were evident in
treated uptake. Non-motile bivalve larvae (not gaping) and large disc diatoms that appeared
intact and health (3/m
3
in treated discharge) where included in these values. The organism in the
size category included: calanoida, copepod nauplii, polychaeta, bivalves, cnidarian, carchesium,
nematode, eggs, and disc diatoms.
Live Organisms 10-50 µm
–
The dominant species in this trial were
Cochlodinium polykrikoides,
C. closterium
and
Gymnodinium sanguineum
.
Other species in this size category included:
E.veridis, Scrippsiella trochoidea, Prorocentrum minimum, Coscinodiscus
sp
.
Stylonychia
sp
.
and tintinnids.
Viable Bacteria and Indicator Pathogens
–
In general, levels of regulated pathogens were low in
all samples regardless of analytical method used.
Enterococci
Uptake Mean
(
cfu/100 ml)
SD
Discharge Mean
(
cfu/100 ml)
SD
Control
1.0
0.00
1.0
0.00
Treated
<1.0
0.00
<1.0
0.00
E. coli
Uptake Mean
(
cfu/100 ml)
SD
Discharge Mean
(
cfu/100 ml)
SD
Control
79.0
42.00
947.4
71.32
Treated
2.7
2.20
1.7
0.58
V. cholerae
Uptake Mean
(
cfu/100 ml)
SD
Discharge Mean
(
cfu/100 ml)
SD
Control
NEG
NEG
NEG
NEG
Treated
NEG
NEG
NEG
NEG
NEG: Negative, Vibrio cholerae O1 and O139 were not present in the sample
Heterotrophic
Plate Counts
Uptake Mean
(
cfu/100 ml)
SD
Discharge Mean
(
cfu/100 ml)
SD
Control
5,833.3
1,283.2
TNTC
N/A
Treated
1,450.0
920.3
TNTC
N/A
TNTC: Too numerous to count
Uptake
Mean/m
3
Uptake
SD
Discharge
Mean/m
3
Discharge
SD
Control
219,265
2,790
4,345
168
Treated
22,235
3,650
23
0
Uptake
Mean/ml
Uptake
SD
Discharge
Mean/ml
Discharge
SD
Control
7,623
742
1,074
23
Treated
1,557
240
10
3