SUMMARY
REPORT ON
RELEASES OF
LABORATORY PRODUCED
PRODUCED CLAMS
CLAMS
SUMMARY REPORT
ON RELEASES
OF LABORATORY
BY
BY
Tom
Tom Gaumer
Gaumer
INFORMATION REPORT
INFORMATION
REPORT 78-4
78-4
Oregon
Oregon Department
Department of
of Fish
Fish and
and Wildlife
Wildlife
August
1978
August 1978
Table of Contents
Contents
Page
No.
Page No.
IINTRODUCTION.
NTRODUCTI ON. •
.
.
.........................
1
1
METHODS
• • . •................................
METHODS
naBa
.............................
Bay
Yaquina
Butter
Clam.Clam ...........................
Butter
ManTra-Il'ffleneck
Manila Littleneck Clams
Clams .....................
Native Littleneck
Littleneck TTh11Z
Clams .....................
Native
Gape:!rCCl ams ...........................
44
44
Netarts
Bay
tsBa.............................
44
...........................
Alsea Ba
Bay ..............................
Coos Bay
Bay ..............................
Coos
55
55
Cogui 11 e Bay
66
Tillamook
Ti
11 amook Bay
B~
................................
Yaguij............................
..
RESULTS
Yaguina Bay
Butter Clams
Clams • .........................
Butter
Clams ...............
Manila Littleneck Clams
Clams .....................
Nati
ve Littleneck
Littl eneck Clams
Nifle
..........................
Gaper Clams •••
Netarts Bay
Bay
Netarts
Clams
Manila Littleneck Clams
Tillamook Bay
Bay
Al
sea Bay
Bay •.
Alsea
.
.
.....................
...........................
........................
.
Coos Bay • • •
Coguill e Bay •
...........................
SUMMARY ................................
APPENDIX ...............................
LITERATURE CITED
CITED
LITERATURE
1
1
1
1
1
1
3
3
55
6
6
6
6
99
10
10
6
5
12
12
12
12
13
13
13
13
16
16
15
16
16
16
16
16
18
18
List of
of Figures
Figures
List
Figure No
No.
Figure
Page
No.
Page No.
.
...
.......
11
Artificial Substrate
Substrate Plots,
Plots, Yaquina
Yaquina Bay
Bay Breakwater
Artificial
Breakwater
2
2
Growth Curve
Curve of
of Butter
Butter Clams
Planted on
on the
Breakwater,
Clams Planted
the Breakwater,
Yaquina Bay
Bay (Vertical
(Vertical Lines
Lines Indicate
Indicate Range
Range in
in mm),
mm), 1978.
1978.
3
3
44
55
.
.
2
2
88
Growth Curve
Curve of
of Native
Native Littleneck
Littleneck Clans
Clams Planted in
in Artificial
Artificial
Substrate Plot,
Plot, Yaquina
Yaquina Bay
(Vertical Lines
Indicate Range
Range
Lines Indicate
Bay (Vertical
.........................
in
mm), 1977
1977 •
• • • . . • . • • • . • • . • . . . '"
in mm),
11
11
Growth Curve
Curve of
of Manila
Manila Littleneck
Clams Planted in
in Fenced,
Fenced,
Littleneck Clams
Unfenced and
and Eelgrass
Eelgrass Covered
Covered Areas
Areas of
of Netarts
Netarts BayBay
. .......
.
Unfenced
14
14
Growth Curve
Curve of
of Manila
Manila Littleneck
Clams Spawned and Planted
Littleneck Clams
from Normal
Normal and
and Fast
Fast Growing
Growing Brood
Brood Stock
Stock in
in Netarts
Netarts Bay.
Bay.
from
15
15
.
.
.
List of
of Tables
Tables
List
No.
Table
Table No.
1
1
22
33
Growth and Survival
Survival of Butter Clams
Planted in
in Artificial
Artificial
Clams Planted
Substrate Plots,
Plots, Yaquina
Yaquina Bay Breakwater,
1968-78
. . •.......
.
Substrate
Breakwater,
1968-78
7
Growth
Butter Clams
Planted on the
the Yaquina
Yaquina
Growth and
and Survival
Survival of Butter
Clams Planted
Bay Breakwater,
Breakwater, 1977
1977 •.....................
• • • • • • . • • • • • • • • • .
99
Summary
Summary of
of Size-Density
Size-Density Manila
Manila Clam Plants
Plants at
at Riverbend
Riverbend Marina,
Marina,
Yaquina Bay, Bay,
1972 • •
• • •.......................
•••••••.•.••.•..
Yaquina
1972
4
4
7
Summary of
of Clams
Clams Remaining
Remaining in
in Fenced,
Fenced, Unfenced,
Unfenced, and
and Eelgrass
Eelgrass
Summary
Covered
Plots, Netarts
Netarts Bay,
1974-77 . • • • • . • .
Bay, 1974-77
Covered Test
Test Plots,
...........
10
10
13
13
List of Appendix Figures
Figures
Figure Letter
Letter
A
A
Location of
Experimental Clam Plants, Yaquina
Yaquina Bay,
Bay, 1968-72
1968-72
Location
of Experimental
19
19
B
B
Location of
Experimental Clam Plants,
Plants, Netarts
Netarts Bay,
Bay, 1971-74
1971-74
Location
of Experimental
20
20
C
C
Location of
Experimental Clam
Clam Plant,
Plant, Tillamook Bay,
Bay, 1971
1971
Location
of Experimental
21
21
oD
Location of
Experimental Clam Plants,
Plants, Alsea
Alsea Bay,
Bay, 1971-72
1971-72
Location
of Experimental
E
E
Location of
of Experimental
Experimental Clam Plants,
Plants, Coos
Bay, 1973
1973 .......
.
Coos Bay,
23
23
F
F
Location of
of Experimental
Experimental Clam
Clam Plant,
Location
Coquille Bay,
Bay,1973.
1973 .....
Plant, Coquille
24
24
-
22
22
Summary Report
Report on
Releases of Laboratory
Laboratory Produced
Produced Clams
Clams
on Releases
IINTRODUCTION
NTRODUCTI ON
In 1968
1968 the Oregon
Oregon Fish
Fish Commission
(now Oregon Department
Department of
of Fish
Fish and
and Wildlife)
Wildlife)
In
Commission (now
initiated
funded studies
to develop
develop techniques
techniques to
to spawn
spawn and
and rear
rear several
several
initiated P.L.
P.L. 88-309
88-309 funded
studies to
species of
species
of bay
bay clams.
clams.
After
spawning and rearing
rearing studies,
studies, we
we planted
planted
After our
our successful
successful spawning
the
clams on
various tideflats
tideflats of
of several
several estuaries
estuaries to
to
the laboratory-produced
laboratory-produced juvenile
juvenile clams
on various
evaluate
evaluate their
their growth
growth and
and survival
survival (Figures
(Figures A-F
A-F in
in Appendix).
Appendix).
This
report summarizes
summarizes the
cur field
field work on
on Yaquina,
Yaquina, Netarts,
Netarts,
This report
the results
results of our
Tillamook,
Alsea, Coos
Coos and
and Coquille
Coquille estuaries.
estuaries.
Tillamook, Alsea,
METHODS
METHODS
Yaquina
Bay
naBa
Four
reared for
for planting
planting experiments
experiments
Four species
species of clams
clams weY'e
were spawned
spawned and
and juveniles
juveniles reared
in Yaquina
Yaquina Bay.
Bay.
in
Butter
Butter Clam,
Clam.
Butter
successfully spawned
spawned and
and
Butter clams
clams saxidomus
Saridomus giganteus
giganteus were
were successfully
reared
reared in
in the
the laboratory
laboratory (Phibbs,
(Phibbs, 1968
1968 and
and 1969).
1969).
Approximately
30,000 of
of the
the
Approximately 30,000
juvenile clams
clams were
were marked
marked with
with sodium
sodium alizarin
alizarin rnonosulfonate
monosulfonate using techniques
techniques
juvenile
described
descri
bed by
by Hidu
Hi du and
an d Hanks
Hanks (1968).
(1968).
These
rked clams
cl ams were
then used
used in
inaa habitat
habi tat
These rna
marked
were then
preference study
study in
in Yaquina
Yaquina Bay
Bay where we attempted
attempted to
to evaluate
eva] uate the
the effects
effects of
of various
various
preference
ubstrate types
types upon
upon growth
growth and
and survival
survival.
substrdte
The test
test plots
plots were
located on
on the
the
The
were located
north side
side of
of the
the breakwater
breakwater in
in the
the Department's
Department's shellfish
shellfish preserve
preserve (Figure
(Figure 1).
1).
The experiment
experiment was
was designed
designed to
to evaluate
evaluate the
the following
following substrate
substrate types:
types:
The
Plot
1 was
control consisting
primarily of a mud-sand
plot 22 contained
contained
Plot 1
was the
the control
consisting primarily
mud-sand substrate;
substrate; plot
crushed rock
rock 19
19 mm-38
mm-38 mm;
mm; plot
plot 33 contained
contained river
river run
run rock
rock 19
19 mm;
mm; plot
plot 44 contained
contained
crushed
crushed
rock 19
19 mm;
plot 5 contained
rock 19
19 mm-38 mm;
and plot
plot 66 contained
contained
crushed rock
mm; plot
contained river rock
mm; and
crushed rock
rock 38
38 mm-iS
mm-76 mm.
mm.
After allowing the
the plots
settle for
for one week,
juvenile butter
butter clams
clams were
were
plots to
to settle
week, juvenile
placed
in aa 1.2
1.2 xx 1.2
1.2 m
plot at
at aa density
density of
of 100
100 clams/O.09
clams/0.09 m2.
m2 •
placed in
m portion
portion of
of each
each plot
The
planted in
in December
December 1968.
1968.
The clams
clams were
were planted
The
old and
and
The clams
clams were
were eight months old
, 1 '
~-~- i -~-- ~~ 2 I ~ -~B:
I
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,
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1.
1.
2.
2.
3.
3.
4.
4,
5.
5.
6.
6.
~I
t
YaqtAitia'Bav
Yaq{Ait1~
131
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/
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-$-
Control
(natural substrate)l/
Control plot
plot (natural
substrate)'/
Crushed gravel
gravel 3/4"
3/4" -- 1½"
F 2"
Crushed
River-run
gravel >3/4"
>3/4"
River-run gravel
Crushed gravel
grave 1 >3/4
>3/4"
Crushed
River-run
gravel
River-run gravel 3/4"
3/4" - 1'1½"
-2"
Crushed
Crushed gravel
gravel 1½"
1'-2" -- 3"
3"
native littlenecks
littlenecks (v.
(v.
V LNLN= =
native
!J
B=
B
I
o
0
Figure
Figure 1.
1.
J
tOOO
tacO
.:2.000
000
$000
3000
"'tCOO
4000
staminea)
stwninea)
planted 977o
p1anted9!70
butter
clams (s.
(5. giganteus)
butter clams
planted 12/69
planted
'0/6B
COO Fnrr
Fr
4000
Location and
and Substrate
Substrate Composition
Composition of
of Artificial
Artificial Substrate
Substrate Test
Test Plots,
Plots, Yaquina
Yaquina Bay.
Bay.
Location
-3-3-
averaged 2.9
2.9 mm
mm in
·in shell
shell length
length when
when planted.
planted.
averaged
Survival
growth was
monitored
Survival and
and growth
was monitored
by annually
annually sampling
sampling randomly
randomly selected
selected 0.09
m2 portions
portions of
of each
each test
test plot.
plot.
by
0.09 m2
In 1970,
1970, 600
600 juvenile
juvenile butter
butter clams
clams were
were planted
planted in
in aa 0.9
0.9 xx 3.0
3.0 mmplot
plot in
in natural
natural
In
substrate near
near the
the base
base of
of the
the Yaquina
Yaquina Bay
Bay breakwater.
breakwater.
substrate
when
planted and
and averaged
averaged 20
20 mm.
mm.
when planted
The
22 months
months old
old
The clams
clams were
were 22
They
paint to
to distinguish
distinguish
They were
were marked
marked with
with enamel
enamel paint
them
natural set.
set.
them from
from natural
Manila
Littleneck Clams,
Clams.
Manila Littleneck
Manila littleneck
littleneck clams
clams
Manila
successfully
spawned in
in the
the laboratory
laboratory (Phihbs,
(Phibbs, 1970).
1970).
successfully spawned
Venerupis
Tlenerupis philipinarium
philipinarium were
The resultant
resultant 4,000
4,000 juveniles
juveniles
The
were planted
planted in
in upper
upper Yaquina
Yaquina Bay
Bay near
near the
the mouth
mouth of
of McCaffery's
McCaffery's Slough.
Slough.
were
2.4
x 7.6
7.6 mm test
test plot
plot was
placed at
at the
the 00 to
to 0.45
0.45 mm tide
tide level.
level.
2.4 x
was placed
The
The
The clams
clams were
were
The
2 and
planted
3.0 mm
in shell
shell length.
length.
planted at
at aa density
density of
of 20/0.09
20/0.09 m
m2
and averaged
averaged 3.0
mm in
In October
planting of
5,340 Manila
Manila clams
clams was
was
In
October 1971,
1971, an
an additional
additional experimental
experimental planting
of 5,340
made
Island to
to evaluate
evaluate optimum
optimum size
size and
and density
density of
of Manila
Manila juveniles
juveniles
made on
on McCaffery's
McCafferys Island
at
time of
of planting.
planting.
at time
Three
10-month-old clams
clams averaging
averaging 3.7,
3.7, 7.0
7.0 and
and
Three groups
groups of
of 10-month-old
11.4
11.4 mm
mm were
were planted
planted at
at four
four different
different densities
densities (50,
(50, 80,
80, 125
125 and
and 200/0.09
200/0.09 m2).
m2 ).
In
of Yaquina
Yaquina Bay.
Bay. One
One
In 1972
1972 we
we planted
planted Manila
Manila clams
clams in
in four
four additional
additional areas
areas of
plant
12,950 Manilas
in April
across from
from the
the Riverbend
R'iverbend Marina
Marina and
and was
was
plant of
of 12,950
Manilas occurred
occurred in
April across
also
to evaluate
density for
for planting
planting Manilas.
Manilas.
also designed
designed to
evaluate optimum
optimum size
size and
and density
Nine test
Nine
plots
separated into
into three
three groups
groups of
of three
three plots
plots each.
each.
plots were
were established
established and
and separated
Group
Group
one clams
clams were
were planted
planted at
m2 ; group
group two
two at
at 125/0.09
125/0.09 m2;
m2 ; and
and
One
at densities
densities of
of 200/0.09
20O/OO9 m2;
group three
three at
at 80/0.09
80/0.09 m2,
m2 •
group
The small
small clams
clams averaged 3.7
mm, the
The
3.7 mm,
the medium-size clams
clams
averaged 6.5
6.5 mm
mm and
and the
the large
large clams
clams were
were 11,0
11.0 nm.
mm.
A second
planting was
made in
in aa 4.6
4.6 m2
m2 plot
plot on
on the
the west
west side
side of
of Sally's
Sally's Bend.
Bend.
A
second planting
was made
The
The plot
plot was
was planted
planted with
with 2,500
2,500 juveniles
juveniles (50
(50 clams/0.09
clams/O 09 m2)
m2 ) in
in October
October 1972
1972 and
and
averaged
6.2 mm.
mm.
averaged 6.2
The
suitability of
of the
the area
area for
for
The planting
planting was
was made
made to
to determine
determine suitability
future
plants.
future plants.
The
third release
release of
Manilas occurred
in July
July 1972
1972 near
near Oregon
Oregon Oyster
Oyster Company.
Company.
The third
of Manilas
occurred in
2 plots
Three
3.3 m
plots were
the 0.97
to 1.5
1.5 mm tide
tide level.
level.
Three 3.3
m2
were estab·lished
established at
at the
0.97 to
Each
plot
Each plot
-4-
'.4-
2 ) of
received 1,800
1,800 Manilas
Manilas (at
(at 50/0.09
an average
average length
length of
of 6.7
6.7 mm.
mm.
received
50/0.09 m
m2)
of an
The fourth
fourth plant
plant involved
involved placing
placing 426,000
f1anilas enmass
enmass in
in aa 353
353 m2
m2 plot
plot on
on
The
426,000 Manilas
the south
south side
side of
of the
the Yaquina
Yaquina Bay
Bay breakwater.
breakwater.
the
These
clams were
were released
released in
in July,
July,
These clams
September and
September
and October
October of
of 1972,
1972.
Native
Littleneck Clams.
Clams.
Native Littleneck
In
1970, 600
juvenile littleneck
littleneck clams
clams
In September
September 1970,
600 juvenile
Venerupis
Venrupis staminea
staminea were
were planted
planted in
in specially
specially prepared
prepared plots
plots containing
containing the
the several
several
substrate described
described in
in the
the butter
butter clam
clam section.
section.
types
types of
of substrate
old
old and
and averaged
averaged 9.9
9.9 mii
mm when
when planted,
planted.
The
11 months
months
The clams
clams were
were 11
They were
were planted
They
planted at
at aa rate
rate of
of 6.3/0.09
6.3/0.09 m2.
m2 •
In
Yaquina Bay.
Bay.
In 1972
1972 we
we planted
planted 4,000
4,000 native
native littlenecks
littlenecks on
on the
the breakwater
breakwater of
of Yaquina
The clams
clams were
were planted
The
planted at a density of 100/0.09
100/0.09 m2
m2 and
and averaged
averaged 9,8
9.8 mm.
mm.
Gaper
Clams.
pJçlas.
Three thousand
thousand laboratory-reared
laboratory-reared gaper
gaper clams
clams Tresus capax
capax were
were
Three
planted
planted in
in Yaquina
Yaquina Bay
Bay in
in 1970.
1970.
25/0.09
m2 •
25/0.09 m2.
The
clams averaged
averaged 13.6
13.6 mm
mm and
and were
were planted
planted at
at
The clams
The clams
clams VJere
planted on
the breakwater
breakwater in
in an
an area
area containing
containing aa
The
were planted
on the
natural popul
population
clams.
natural
ati on of
of adult
adult gaper
gaper clams.
Bay
Netarts Bay
Netarts
Our clam plants
plants in
in Netarts
Netarts Bay
Bay started
started in
in 1971
1971 and
and extended
extended through
through 1974.
1974.
The
The
Manila littleneck
littleneck was
was the
the only
only clam
clam species
species released,
released.
Manila
In
Beach in
in Netarts
Netarts Bay
Bay
In 1971
1971 20,000
20,000 juvenile
juvenile Manilas
Manilas were
were planted
planted near
near Wilson
Wilson Beach
at
a density
density of
of 50
50 clams/O.09
clams/0.09 m2.
m2 •
at a
The
ranged from
from 3.2
3.2 to
to 11.6
11.6 mm
mm in
in length.
length.
The clams
clams ranged
Our primary
primary goal
goal was
was to
to determine
determine the
the suitability
suitability of
of the
the area
area for
for future
future releases,
releases.
Our
In 1973
five test
test plots
plots were
in scattered
scattered locations
locations of
of Netarts
Netarts Bay.
Bay.
In
1973 five
were established
established in
A
A total
total of 10,625
10,625 juvenile
juvenile Manilas
Manilas were
were planted in
in an
an attempt to
to locate
locate areas
areas that
that
might be
be suitable
suitable for
for additional
additional plants.
plants.
might
Each plot
plot was
planted with
with clams
clams at
at
Each
was planted
50/0.09 m2
50/0.09
m2 and
and the
the clams
clams averaged
averaged 7.3
7.3 mm
mm in
in length.
length.
In 1974
1974 two
two plots
plots were
Netarts to
to evaluate
evaluate movement,
movement, survival
survival
In
were established
established in
in Netarts
and
growth of
of Manila
t1anila clams.
clams.
and growth
One
1.5 xx 3,0
3.0 m
plot was
was fenced
fenced with
with 6,3
6.3 mm
mm mesh
mesh wire
wire
One 1.5
m plot
that extended
10.1 cm
em above
the substrate
substrate and
and the
the other
other area
area was
was unfenced.
unfenced.
cloth
cloth that
extended 10.1
above the
Both plots
planted at
density of
5010.09 m2
m2 with
with 2,500
2,500 juvenile
juvenile Manilas
Manilas
Both
plots were
were planted
at a
a density
of 50/0.09
-5-5-
averaging 13.1
13.1 mm,
mm.
averaging
At
test plot
plot was
established about
about
At the
the same
same time
time an
an additional
additional test
was established
75
closer to
to the
the main
covered with
dense eelgrass
eel grass Zostera
Zostera
75 m
m closer
main channel
channel in
in an
an area
area covered
with dense
marina.
marinn.
This area
lower elevation
elevation than
than the
the other
other two
two plots
plots and
and
This
area was
was at
at a
a slightly
slightly lower
planted
at aa density
density of
of 54
54 clams/0.09
clamsjO.09 m2.
m2 •
planted at
This
to (1)
(1) evaluate
This release
release was
was made
made to
evaluate
growth rate
rate at
lower tidal
tidal height
height as
as compared
compared to
to the
the fenced
fenced and
and
the
difference in
in growth
the difference
at a
a lower
unfenced areas
areas and
and (2)
(2) to
to determine
if eelgrass
harbored predators
predators (crabs)
(crabs) which
which
unfenced
determine if
eelgrass harbored
might
might effect
effect clam
clam survival.
survival.
Also
in 1974
1974 two
two test
test plots
plots were
to evaluate
evaluate the
the growth
growth and
and survival
survival
Also in
were established
established to
of
of progeny
progeny from
from selected
selected fast
fast growing
growing adult
adult clams
clams and
and from
from "normal"
"normal" growing
growing adults,
adults.
A total
total of
of 39,114
39,114 juveniles
juveniles averaging
averaging 5.7
5.7 mm
mm were
were planted
planted from
from fast
fast growing
growing adults
adults
A
and 11,375
clams averaging
averaging 55.33 mm
mm were
were released
released from
from 'normal"
"normal" growing
growing adults
adults.
11,375 clams
An
Manilas were
planted in
in adjacent
adjacent areas
areas
An additional
additional 430,200
430,200 laboratory
laboratory reared
reared Manilas
were planted
stocks in
in the
the bay.
bay.
to
to supplement
to attempt
attempt to
supplement the
the existing
existing spawning
spawning stocks
Tillamook
Ti
11 amook
BB~
In
clams in
in
In 1971
1971 we
we planted
planted aa total
total of
of 20,000
20,000 juvenile
juvenile Manila
Manila littleneck
littleneck clams
Bay adjacent
adjacent to
to Hobsonville
Hobsonville Point,
Point.
Tillamook
Tillamook Bay
Our
to determine
determine
Our primary
primary objective
objective was
was to
of the
the area
area for
for future
future releases.
releases.
the
the suitability
suitability of
Ba
In
In 1971
1971 we
we planted
planted 20,000
20,000 juvenile
juvenile Manila
Manila littleneck
littleneck clams
clams in
in Alsea
Alsea Bay
Bay on
on
the north
north shore
shore above
above the
the U.S.
U.S. highway
highway 101
101 bridge.
bridge.
the
were made
made upbay
upbay of
of the
the 1971
1971 plant.
plant.
were
In 1972
1972 two
two additional
additional releases
releases
In
A total
total of
of 19,800
19,800 clams
clams were
were released.
released.
A
SuitSuit-
ability
of the
the area
area for
for future
future clam
clam releases
releases was
was our
our primary
primary objective.
objective.
ability of
Coos Bay
Two
from the
the town
town of
Empire, were
were
Two areas
areas of
of the
the north
north spit
spit of
of Coos
Coos Bay,
Bay, across
across from
of Empire,
planted with
a total
total of
20,000 Manila
Manila clams
clams in
in August
August 1973.
1973.
planted
with a
of 20,000
area
for future
future releases
releases was
was our
our primary
primary concern.
concern.
area for
Suitability of
of the
the
Suitability
-6-6-
Cogui
11 e Bay
Bay
Coguilie
We planted
planted 10,000
10,000 juvenile
juvenile Manila
I~anila clams
clams across
across from
from the
the abandoned
abandoned light
light houses
houses
We
in
in Coquilie
Coquille Bay
Bay in
in August
August 1973.
1973.
Primary objective
to evaluate
suitability of
of
Primary
objective was
was to
evaluate suitability
the area
area for
for future
future Manila
Manila clam
clam plants.
plants.
the
RESULTS
RESUL
TS
Yaguina
Bay
na Bay
Butter
Clams.
Butter Clams.
has
been low.
low.
has been
Survival
butter clams
clams in
in the
the artificial
artificial substrate
substrate test
test plots
plots
Survival of
of butter
After
15 months,
months, survival
survival ranged
ranged from
from 0.5
0.5 to
to 4.5%
4.5% (Table
(Table 1).
1).
After 15
planted
in the
the control
control plot
plot failed
failed to
to survive.
survive.
planted in
Clams
Clams
Our sampling
sampling in
in April
April 1978,
1978, 112
112
Our
months
the clams
clams were
released, showed
showed aa total
total survival
survival rate
rate ranging
ranging from
from
months after
after the
were released,
0%
(for clams
clams planted
planted in
in natural
substrate and
and 19
19 mm
mm minus
minus river
river rock)
rock) to
to 0.8%
0.8% for
for
0% (for
natural substrate
clams
in 19
19 mm
minus crushed
crushed rock.
rock.
clams planted
planted in
mm minus
Growth
combined,
Growth of
of the
the butter
butter clams
clams after
after 15
15 months,
months, for
for all
all substrates
substrates combined,
averaged 20.6 mm;
mm; the
the butters
butters averaged
averaged 2.9
2.9 mm
mm when
when planted.
planted.
In
In the
the artificial
artificial
substrate plots,
plots, growth
growth ranged
ranged from
from 19.3
19.3 mm
mm in
in 38
38 mm
mm to
to 76
76 mm
mm crushed
crushed rock
rock to
to
substrate
21.5
21.5
mm in
rr~
in 19
19 to
to 38
38 mm
mm crushed
crushed rock.
rock.
Twenty-four
release, growth
growth
Twenty-four months
months after
after release,
ranged
33.6 mm
released in
in 19
19 to
to 38
38 mm
river rock
rock to
to 38.1
38.1 mm
mm
ranged from
from 33.6
mm for
for clams
clams released
mm minus
minus river
for
planted in
in 19
19 mm
mm minus
minus river
river rock.
rock.
for clams
clams planted
curve
of butter
butter clams.
clams.
curve of
Figure
the average
average growth
growth
Figure 2
2 shows
shows the
After 119
119 months
months the
the butter
butter clams
clams averaged
averaged 71.8
71.8 mm
mm in
in
After
length.
length.
One
the effect
digging and
and handling
handling
One parameter
parameter that
that was
was not
not measured
measured was
was the
effect of
of digging
on survival
survival and
and growth;
growth; both
both probably
probably were
were important.
important.
on
Survival
in aa natural
substrate envi
environment
Survi val of
of butter
butter clams,
clams, planted
planted in
in 1970
1970 in
natural substrate
ronment
at
the base
the Yaquina
Yaquina Bay
breakwater, was
51. 7% after
after 83
83 months
months in
in the
the test
test
at the
base of
of the
Bay breakwater,
was 51,7%
plot (Table
(Table 2).
2).
plot
2 section,
Each
previous"ly sampled,
sampled, was
was removed
removed
Each year
year aa 2.5
2.5 m
m2
section, never
never previously
to
mi na te adverse
adve rse effects
effects of
of handling.
handl i ng.
to eli
eliminate
in survival
survival is
is unknown.
unknown.
in
The
reason for
for the
the annual
annua 1 increases
increases
The reason
Either
randomly distributed
distributed when
when
Either the
the clams
clams were
were not
not randomly
planted or
there was
differences from
from one
one end
end of
of the
the plot
plot to
to
planted
or there
was subtle
subtle environmental
environmental differences
Table
Table 1.
1.
rowth and
Surviyal of
Growth
and Survival
of Butter Clams
Clams Planted
SubstratePlots,
Plots,
YaquinaBay
BayBreakwater,
Breakwater,
Plantedinin Artificial
Artificial Substrate
Yaquina
1968~78
196878
Months after
va 1
Mean
Months
after Survi
Survival
release
size
(mm)
(%)
size
(m)
(%)
Substrate
type
Date
sampled
Control
12/15/68
6/8/69
12/26/69
0
66
12
100.0
1.5
0.0
2.9
11.1
Crushed
Crushed rock 12/15/68
19mm
19mm to
to 38mm
38mm 6/8/69
12/26/69
3/25/70
12/9/70
4/12/73
4/25/74
4/28/75
4/16/76
4/6/77
4/25/78
0
0
66
12
15
15
24
52
52
64
76
88
100
112
100.0
3.3
0.0
0,0
2.0
0.8
0.1
0.1
0.1
0.1
0.1
0.1
2.9
10,3
10.3
Ri
ver Run
Run
River
19mm 19mm
12/15/68
6/8/69
12/26/69
3/25/70
12/9/70
4/12/73
0
66
12
15
15
24
52
100.0
1.0
0.0
0.5
0.2
0.0
-
Substrate
type
Date
sampled
Crushed
12/15/68
6/8/69
12/26/69
3/25/70
12/9/70
4/12/73
4/25/74
4/28/75
4/16/76
4/6/77
4/25/78
00
66
12
12
15
24
52
64
76
88
100
112
100.0
4.5
1.0
4.5
3.4
2.4
1.7
1.6
1.1
0.9
0.8
2.9
10.5
20.8
23.8
38.8
61.2
62.2
64.7
65.6
69.1
72.7
Ri
ver Run
Run
12/15/68
River
19mm
38mm 6/8/69
19mm to
to 38mm
12/26/69
3/25/70
12/9/70
4/12/73
4/25/74
4/28/75
4/16/76
4/6/77
4/25/78
0
0
100.0
6
12
12
15
15
24
52
64
76
76
88
100
100
112
112
0.8
D.8
1.8
0.9
0,7
0.7
0.2
0.3
0.3
0.3
0.3
0.3
2.9
7.4
20.7
23.3
36.5
36,5
61.0
63.2
65.3
0
0
100.0
6
12
15
15
24
24
7.3
1.5
2.4
2.5
19m 19mm
-
-
24.4
38.6
56.1
59.1
63.0
64.9
71.4
72.1
2.9
7.9
--
23.8
41.0
--
Months
val
Monthsafter
after Survi
Survival
re
lease
release
(%)
(%)
H
Crushed
38mm to
to 75mm
76mm
38nin
12/15/68
6/8/69
12/26/69
3/25/70
12/9/70
1972
4/12/73
4/25/74
4/28/75
4/16/76
4/6/77
4/25/78
6
6
-
-
52
64
76
88
100
112
112
--
1.7
1.4
1.3
0.9
0.9
0.4
Mean
Mean
size
(mm)
size (mm)
-
67.0
71.8
2.9
9.2
19.6
22.2
38.2
49.9
58.5
60.3
62.3
63.6
69.1
70.9
"
;
90
9C
- - ARTIFICIAL
ARTIFICIAL SUBSTRATE
SUBSTRATE PLOT
I
- - - BASE OF
OF BREAKWATE
BREAKWATER PLOT
"---BASE
LOT
80'
BC
If
70
7C
---E
6C
E 60
'-'
U1
t
r/rl
i=--r 1
1 ///1
U/f"
SC
.I
:i: 50
lIt9
4O
Z 40
T'
1
I
03
00
I
I
1
W
-J30
.-J
30
/I,"
T //
~
/'r /
// QCLAMS PLANTED
/iCLAMS
20
2C
I
j
10
I0
.telA"
S PLANTED
I-CLAMSPLAN1ED
I
30
10
20
30
40
50
60
70
I
80
I
90
I
I
100
300
110
310
120
320
130
33
140
140
AGE (MONTHS)
Figure 2.
2.
Growth Curve
Curve of
of Butter
Butter Clams
Clams Planted
Planted on
on the
the Breakwater,
Breakwater, Yaquina
Yaquina Bay
Bay (Verti-cal
(Vertka1
Lines Indicate
Indicate Range
Range in
in mm),
mm), 1978.
1978.
Lines
-9the
the other
other which
which affected
affected survival.
survival.
Table
2.
Table 2.
Growth
Growth and
and Survival
Survival of
of Butter
Butter Clams
Clams Planted
Planted on
on the
the
Yaquina
Bay Breakwater,
Breakwater, 19771/
1977~
Yaquina Bay
Date
Date
Samp
led
Sampled
Mean Shell
Shell
Mean
Length (mm)
(mm)
Percentage
PeFEiitage
Survi va1
Survival
Age of
of Clams
Cl ams
Ago
7-13-72
7-13-72
7-30-73
7-30-73
7-19-74
7-J9-74
7-9-75
7-9-75
7-27-76
8-2-77
8-2-77
37.0
37,0
46.7
46.7
48.4
48.4
53.7
53.7
60.0
60.0
65.4
65.4
31.
7
31.7
46.7
46.7
59.2
59.2
65.0
65.0
68.3
68.3
51.7
51.7
44,5
44.5
57.0
57.0
68.0
68.0
80.0
80.0
92.0
92.0
105.0
105,0
(Months)
(Months)
Months
In
Months In
Plot
Plot
22.0
22.0
34.5
34.5
46.0
46.0
58.0
58.0
70.0
70.0
83.0
83,0
l!
Butter clams
clams averaged
averaged 20
20 mm
mm when
when planted.
planted.
Butter
1/
Growth
butter clams
in the
the natural
natural substrate
substrate lagged
lagged behind
behind aa comparable
comparable
Growth of
of butter
clams in
group
planted in
in the
the artificial
plot located
located 91
91 mm away
away (Figure
(Figure 2).
2).
group planted
artificial substrate
substrate plot
Clams
Clams
in
those in
in the
the
in the
the natural
natural substrate,
substrate, after
after 105
105 months,
months, averaged
averaged 65
65 mm
mm whereas
whereas those
artificial
artificial substrate
substrate averaged
averaged 68
68 mm.
mm.
Manila Littleneck
Littleneck Clams,
Clams.
Manila
Twelve months
months after
after planting
planting 4,000
4,000 juvenile
juvenile Manila
Manila
Twelve
littleneck clams
clams on
on McCaffery's
McCaffery's Island
Island we
we found
found that
that 4.6%
4.6% had
had survived.
survived.
littleneck
months <1.0%
<1.0% survived.
survived.
months
After
24
After 24
Evidence
flooding and
and silt
silt deposition
deposition was
was
Evidence of
of severe
severe winter
winter flooding
seen on
on the
the tideflat,
tideflat.
seen
In
Island in
In 1971
1971 we
we repeated
repeated planting
planting Manila
Manila clams
clams on
on McCaffery's
McCaffery's Island
in a
a sizesizedensity
experiment.
density experiment.
Eight
release we
failed to
to find
find any
any surviving
surviving
Eight months
months after
after release
we failed
clams.
clams.
clams planted
planted in
in aa size-density
size-density experiment,
experiment, across
across from
from Riverbend
Riverbend Marina
Marina
Manila
Manila clams
on
on Yaquina
Yaquina Bay,
Bay, experienced
experienced good
good growth
growth but
but poor
poor survival
survival after
after one
one year
year (Table
('Table 3).
3).
Growth was
fastest for
for Manilas
Manilas planted
planted at
at 6,5
6.5 mm
mm and
and at
at densities
densities of
of 200/0.09
200;0.09 m2
m2
Growth
was fastest
whereas
whereas survival
survival was
was highest
highest for
for clams
clams planted
planted when
when 11.0
11.0 mm
mm in
in size
size and
and at
at aa density
density
of 80/0.09
80;0.09 m2.
m2 •
of
After 13
13 months
the clams
clams averaged
averaged 30.8
30.8 mm
mm and
and survival
survival was
was 1.5%.
1.5%.
After
months the
A
planting of
clams on
on Sally's
Sally's Bend
Bend was
was checked
checked 66 months
months later
later
A planting
of 2,500
2,500 Manila
Manila clams
and
and we
we found
found no
no surviving
surviving clams,
clams.
-10-10-
3.
Table 3.
Table
Plot
Plot
No.
No.
11
22
3
3
44
55
66
7
7
88
99
Total
Total
Summary of
Hanila Clam
Clam Plants
Plants at
at Riverbend
Riverbend
Summary
of Size-Density
Size-Density Manila
Harin a , Yaquina
Yaquina Bay,
Bay, 1972.
Marina,
1972 .
Planting
i'ianting
size
(mm)
size (mm)
(4/19/72)
Recovery
ecovery
size
(mm)
size (mm)
(5/4/73 )
80
80
80
80
80
80
125
125
125
125
125
125
200
200
200
200
200
200
3.7
3.7
6.5
6.5
11.0
11,0
3.7
3.7
6.5
6.5
11.0
11.0
3.7
3.7
6.5
6.5
11.0
11.0
29.2
29.2
30.7
30,7
31.
31.77
29.6
29.6
1,215
1,215
7.1
7.1
30.8
30.8
Pl
anting
Planting
2)
density/(0.09m
dens i ty/
-
32.2
32.2
28.9
28.9
33.6
33.6
-
rwmoer
Number
Recovered
Recovered
Percen t
Percent
(5/4/73)
Recovery
Re cpy_
33
11
66
11
00
22
22
33
0
0
3.8
3.8
1.3
1.3
7.5
7.5
1.3
1.3
0.0
0.0
2.5
2.5
2.5
2.5
3.8
3.8
0.0
0.0
18
18
1.5
1.5
The
release of
clams in
in three
three test
test plots
plots near
near Oregon
Oregon Oyster
Oyster
The release
of 5,400
5,400 Manila
Manila clams
Company initially
results with
survi vals ranging
ranging from
from 12.8
12.8
Company
initially produced
produced encoura9ing
encouraging results
with survivals
to 34.4%
34.4% after
after nine
nine months.
months.
to
Twenty-one months
months after
after release
release all
all planted
planted clams
clams
Twenty-one
had
had died.
died.
A
release of
s on
on the
the south
south side
side of
of the
the Yaquina
Yaquina Bay
Bay breakwater,
breakwater,
A release
of 426,000
426,000 Hanila
Manila s
to
rearing clams,
produced less
less than
than 1%
1%
to evaluate
evaluate the
the suitability
suitability of
of that
that area
area for
for rearing
clams, produced
survival after
after 20
20 months.
months.
survival
Poor
the substrate
substrate and
and exposure
exposure of
of the
the
Poor stability
stability of
of the
area to
to strong
strong wave
wave action
action during
during southwest
southwest winds
winds probably
probably contributed
contributed to
to the
the
area
massive
mortality in
in that
that area.
area.
massive mortality
Native Littleneck
Littleneck Clams.
Clams.
Native
Native littleneck
planted in
in September
September 1970
1970 in
in
Native
littleneck clams
clams planted
an
an artificial
artificial substrate
substrate plot were
were sampled annually to
to assess
assess growth.
growth. The
The study
study
was discontinued
discontinued in
in 1977
1977 due
due to
to the
the small
small number
number of
of clams
clams remaining.
remaining.
was
The
The clams
clams
were 10
10 mm
mm when
planted and
and averaged
averaged 48.9
48.9 mm,
mm, 79
79 months
months later
later (Figure
(Figure 3).
3).
were
when planted
Due to
to
clams in
in the
the intial
intial experiment
experiment and
and poor
poor survival,
survival, all
all clams
clams
the small
the
small numbers
numbers of
of clams
were remeasured
remeasured annually
annually since
since 1972;
1972; consequently,
consequently, growth
growth of
of the
the clams
clams may
may have
have been
been
were
retarded due
due to
to handling.
handl ing.
retarded
None of
the 4,000
4,000 native
native littleneck
littleneck clams
clams planted
planted on
on the
the Yaquina
Yaquina Bay
Bay breakbreakNone
of the
water in
in 1972
1972 were
were found
found alive
alive in
in July
July 1973.
1973.
water
These clams
clams were
vJere planted
planted in
in aa natural
natural
These
70
---EEo
60
E
.........
J:
I
4
50
T
--'1
1/
1
C
Z
z
W30
w30
-1
J
.--
1
I
t-'
t-'
I
r/
20
10
10
IT
T
I- 40
c.9
.,..........~
'-CLAMS
to
IO
20
PLANTED
30
40
30 40
50
60
70
80
90
100
110
too UO
!20 130
120
130
140
140
150
ISO
(MONTHS)
AGE (MONTHS)
Figure
3.
Fiuure 3.
Growt~ Curve
Substrate Plot,
Plot, Yaquin
Yaquinaa
Growtft
Curve of
of Native
Native Littleneck
Littleneck Clams
Clams Planted
Planted in
in Artificial
Artificial Substrate
Bay
(Vertical Lines
Lines Indicate
Indicate Range
Range in
in mm),
rrrn), 1977.
1977.
Bay (Vertical
-12-12-
substrate
area where wild
\'/ild native littleneck clams
clams already existed.
existed.
substrate area
Gaper
Clams.
2LPams.
None
three thousand juvenile gaper clams
clams planted
planted on the
the
None of the
the three
Bay breakwater
breakwater survived.
survived.
Yaquina Bay
No
plants of
of laboratory
laboratory reared
reared juvenile
juvenile
No additional
additional plants
clams were
were attempted.
attempted.
gaper clams
Netarts Bay
We have
tchery produced
produced
We
have had
had various
various degrees
degrees of
of success
success with
with our
our releases
releases of
of (lie
htchery
juvenile clams
clams in
in Netarts
Netarts Bay.
Bay.
juvenile
Litt'leneck Clams.
Clams.
t·1anila Littleneck
Manila
An
initial release
release in
in 1971
1971 of 20,000 Manilas
!'1anil as near
An initial
Beach was
was nearly
nearly aa total
total failure,
fail ure.
Wilson Beach
1%
clamS survived.
survived.
1% of
of the
the young
young clams
planting, less
less than
than
Eight months
months after planting,
The
native littleneck,
The area
area of release
release contained native
gaper and
and cockle
incompatible with juvenile
juvenile Manila
Manila clams
clams
cockle clams
clams suggesting something incompatible
existed in
in the area during
during and/or following
following time
time of
of release.
release.
The
in five
five different
different test plots
plots in 1973
1973 to
to attempt
The release
release of
of Manna
Manila clams
clams in
to
locate suitable
suitable release
re'lease sites produced discouraging
discouraging results.
results.
to locate
Ten
months after
Ten months
release,
release, 8.3% of the
the clams
clams released in
in one test
test plot
plot remained
remained alive.
alive.
None of the
the
in the
the remaining
remaining test
test plots
plots were alive,
alive.
clams in
Our
plantings of Manila clams
c'lams in
in 1974 to
to determine survival,
survival,
Our experimental
experimental plantings
cl ams showed that
that Manilas
Manil as were quite
quite mobile.
mobil e.
growth and movement of clams
Two
Two months
after release
release 80% of the
the clams in
in the
the fenced
fenced area were alive whereas 49%
49% of
of the
the
clams
clams released in
in the unfenced
unfenced plot
plot were recovered;
recovered; 15.7%
15.7% were recovered
recovered from
from the
the
eel
grass covered
covered test
test plot.
plot.
eelgrass
the movement of clams
cl ams from
from the
the unfenced
unfenced
Because of the
areas,
areas, comparison
compaY"ison of survival
survival between
between the
the three
three areas
areas was
was inconclusive.
inconclusive.
the test
test plots
plots is
is shown
shown in
in Table
Table 4.
4.
remaining in each of the
Clams
Although the
the eelgrass
eelgrass
plot
planted at a
0, slightly
slightly denser
denser concentration
concentration than
than the
the other
other two
two plots
plots
plot was
was planted
2 vs
(54.0.09
m2 ), fewer
fewer clams
clams remained
remained in
in the
the area,
area.
(54.0.09 m
m2
vs 50/0.09 m2),
Part of this
this might
be
to predation
predation from crabs that
that inhabited
inhabited the
the eelgrass beds
beds since
since many
many
be attributed to
of the remaining
remaining valves
valves of dead
dead clams
clams showed
showed evidence
evidence of
of breakage.
breakage.
Manila clams
clams planted in
in the
the eelgrass plot
plot averaged
averaged 40,0
40.0 mm
mm 36
36 months
months after
after
Manila
-13-13release.
release.
This
in the
the fenced
fenced and unfenced
unfenced
This \'!as
was considerably
considerably larger
larger than
than clams
clams planted
planted in
plots
averaged 37.8
37.8 and
and 33.8
33.8 mm,
mm, respectively
respectively(Figure
(Figure4),.
4).
plots which averaged
Table 4.
4.
Test Plot
Plot
Fenced
Unfenced
Eelgrass
Eel grass
]j
1/
Summary of Clams
Clams Remaining
Remaining in
in Fenced,
Fenced, Unfenced,
Unfenced, and
and
Eelgrass
Eelgrass Covered
Covered Test
Test P'lots,
Plots,'Netarts
Netarts Bay,
Bay, 1974-77':;.
1974-777.
8/74
_-3,D4
10/74
3.7
3.7
3.2
3.2
2.4
0.6
0.6
2.3
2.3
1.3
1.3
Date
5/75
5/76
6/77
2,0
2.0
0.8
0.2
1.8
0.1
0.1
0.8
0.8
0.2
0.2
0.1
Values
remaining in
in test plots.
Val ues are clams/ni2
clams/m 2 remaining
plots.
Results
survival of clams
clams spawned from
from 'fast"
"fast"
Results of our
our stud'ies
studies on
on growth
growth and
and survival
and "normal" growing
growing brood
brood stock showed
showed that
that after
after 34
34 months,
months, progeny
progeny from
from fast
fast
growing clams averaged
averaged 31.5 mm as compared to
to 29.2
29.2 mm
mm for
for normal
normal growing
9rowing clams
clams
(Figure
5).
(Figure 5).
The
The
"normal"
98/0.09 m2
m2 whereas
whereas "fast"
"fast"
'normal" size
size clams
clams were
were planted
planted at a density of 98/0.09
growing clams averaged
averaged 113
113 clams/0.09
clams/0.09 m2.
m2 •
Tillamook~
-Tiliamook.L
-
We
Y'ealized no
no survival
survival from the 20,000 juvenile
juvenile Manila
Manila littleneck
littleneck clams
clams
We realized
Point in
in Tillamook
Tillamook Bay.
Bay.
planted adjacent to Hobsonville Point
Excessive wave action and
and
appeared to
to be
be the
the major
major factors
factors effecting
effecting survival.
survival.
beach exposure appeared
Alsea Bay
Ba
None
None of the 20,000 juvenile
juvenile Manila
Manila littleneck
littleneck clams
clams planted
planted in
in 1971
1971 in
in AlAlsea
sea
Bay appeared
appeared to
to survive,
survive.
Bay
Beach erosion
erosion during
during heavy
Beach
heavy winter runoff appeared to
to
be aa factor.
factor.
be
Results of the
the 1972
1972 release
release of 19,800
19,800 Manila clams uphay
uphay of
of the
the 1971
1971 plant
plant
Results
in Alsea Bay produced
produced similar
similar results
results to
to the
the 1971
1971 plant
plant witi
witi' only 1 clam
in
from 7,3
7.3 m2
m2 of
of sample
sample area.
area.
recovered
------.
40
"
--.::.-::::-::
---
.... .._....._...
.-..,
E
E
E 30
'-"
I
I(J
,
a
""
-a
'-'
20
Z
W
II-
.~.
.......
./~.:::: ........
/'
-l
--EELGRASS
............... UNFENCED
10
- - - FENCED
10
10
20
30
40
50
60
70
'70
AGE (MONTHS
(MONTHS AFTER
AFTER RELEASE)
Figure 4,
Figure
4.
Growth
Curve of
of Manila
Littleneck Clams
Clams Planted
Planted in
in Fenced,
Fenced, Unfenced
Unfenced and
and Eelgrass
Eelgrass
Growth Curve
Manila Littleneck
Covered
of Netarts
Netarts Bay,
Bay, 1978.
1978.
Covered Areas
Areas of
NORMAL- GROWIN G BROOD STOCK
- - - FAST- GROWING
40
BROOD STOCK
..-
.-..
E 30
/,'
--
;/'
E
/'
/'
.
/.
020
l·J
...J
-:.:------
/'
:c
Z
",0
-- ..
/'
~
I
I
~
/-
~
01
101-/:"
10
to
H
Figure
Figure 5.
5.
H
20
30
40
50
60
70
AGE
AGE (MONTHS
(MONTHS AFTER RELEASE)
Growth
Curve of Hanila
Littleneck Clams
Clams Spawned
Spawned and
and Planted
Planted from
from Normal
Normal and
and Fast
Fast
Growth Curve
Manila Littleneck
Growing
Brood Stock
Stock in
in Netarts
Netarts Bay,
Bay, 1978.
1978.
Growing Brood
fl
-16-16-
Coos Bay
The
the north
in 1973 with
with 20,000
The two
two areas
areas on
on the
north spit of Coos
Coos Bay,
Bay, planted
planted in
Manila
clams, were resurveyed
resurveyed nine
nine months
months later.
later.
Manila littleneck clams,
clams was seen.
seen.
No evidence of
of live
live
No
Strong
Strong wave
wave action
action from
from passing
passing ships
ships and
and winter storms might
have
planted set.
set.
have destroyed
destroyed the newly planted
Cog ui 11
llee BBay
a
None
in August 1973,
1973, were alive
None of
of the
the 10,000 Manila
Manila littleneck
littleneck clams,
clams, planted in
nine
later.
nine months later.
Inadequate
Inadequate substrate
substrate and
and low
low winter
winter salinities
salinities probably
attributed
attributed to
to the total
total mortality.
CnED
LITERATURE CITED
Hidu,
James E,
E. Hanks,
Hanks. 1968.
Hidu, Herbert and dames
1968.
with alizarin sodium
sodium monosulforate.
monosulforate.
Vital staining
stainin9 of bivalve
bivalve mollusk shells
shells
Vital
Proc.
Proc. Nat.
Nat. Shellfish
Shellfish Assoc.
Assoc. 58:37-41.
58:37-41.
Phibbs,F.D.
Phibbs,
F.D. 1968. Laboratory
Laboratory hatching
hatching and
and rearing
rearing of Pacific coast clams
clams and
Comm.
Fish. Res.
Res. and
and Devel.
Devel. Act,
Act. July
1, 1967 to
to dune
June 30,
30, 1968.
1968.
oysters.
Comm. Fish.
duly 1,
Fi sh Corn.
Comm. of
of Ore,
Ore. Proc.
Rept. 12
pp.
Proc. Rept.
Fish
12 pp.
_ _---,;------,-_.
and oysters",
oysters.
Fish
of
Fish Comm,
Comm. of
tchi ng and
rea ri ng of Pacific
Pacifi c coast
coas t clams
Laboratory ha
hatching
and rearing
1969. Laboratory
Comm.
Comm. Fish.
Fish. Res.
Res. and
and Devel.
Devel. Act.
Act. July 1,
1, 1968
1968 to
to dune
June 30,
30, 1969.
1969.
Ore. Proc.
Rept. 15
pp.
Proc. Rept.
Ore,
15 pp.
Laboratory
coast clams
1970.
1970.
Laboratory hatching
hatching and
and rearing of Pacific coast
and oysters. Comm.
Fish. Res.
Res. and Devel.
Devel. Act,
Act. ,July
1, 1969
1969 to
to dune
June 30,
30, 1970.
1970.
Comm. Fish.
duly 1,
Fish
of Ore,
Ore. Proc.
Rept. 16
pp.
Fish Comm.
Comm. of
Proc. Rept,
16 pp.
SU~~MARY
SUMMARY
Ten
studies on
on the spawning,
spawning, rearing and planting
planting of
of juvenile
juvenile clams
clams
Ten years
years of studies
following results:
results:
has produced the following
has
1.
1.
We were
in spawning and rearing
rearing the
the butter,
butter, Manila
Manila littleneck,
littleneck,
We
were successful
successful in
native littleneck
littleneck and
and gaper
gaper clam.
clam.
native
Clams
these species were raised
raised
Clams of each of these
in
to release
release in
in field
field experiments.
experiments.
in sufficient numbers to
2.
2.
Survival
Survi valof
of butter
butter clams
clams planted
planted in
in artificial
artificial substrate
substrate p"lots
plots was
was low,
low, ranging
from
to 4.5%,
4.5%, 15
15 months
months after
after release.
release.
from 0.5
0.5 to
twelve months
months after
after
One hundred twelve
release, clams
in 19 mm minus
minus crushed rock
rock produced the
the highest
highest survival
survival
release,
clams planted in
(O.8%).
(0.8%).
-17-173.
3,
Growth
in artificial
plots, after 24
24 months,
months,
Growth of butter
butter clams
clams planted
planted in
artificial substrate
substrate plots,
ranged
in 19
19 to
38 mm minus
minus river
rive)' rock
rock to
to 38.1
38.1 mm
mm
ranged from
from 33.6
33.6 mm for
for clams
clams released
released in
to 38
for clams
in 19
19 mm
mm minus
minus river
river rock.
rock.
for
clams planted in
4.
4.
Survival
in aa natural
base of the
Survival of
of butter clams
clams planted in
natural substrate near the base
breakwater \"as
51. 7%, 83 months after
after release.
release.
was 51,7%,
5.
5.
Survival
Survival of Manila
Manila littleneck
littleneck clams,
clams, planted
planted in
in various
various locations of Yaquina
Yaquina
Bay,
extremely low,
low.
Bay, was extremely
Lack of suitable
to
Lack
suitable substrate material
material was suspected to
be a leading factor in
be
in the
the poor
poor survival.
survival.
6.
6.
Few
clams planted
planted in
in Yaquina
Yaquina Bay
Bay survived.
survived.
Few of
of the
the native
native littleneck clams
7.
7.
None
in Yaquina
Yaquina Bay
Bay survived.
survived.
None of
of the
the gaper clams
clams planted in
8,
8.
Plants of Manila littleneck
clams in
in Netarts
Netarts Bay
Bay produced
produced encouraging
encouraging results
results.
Plants
littleneck clams
We
concluded that juvenile
juvenile Manilas
Manilas are
quite mobile which makes evaluating
evaluating
We concluded
are quite
survival difficult,
survival
difficult.
IQanilas grew
grew faster
faster when
planted in
in eelgrass
eelgrass beds
beds at
at aa
Manilas
when planted
slightly lower tidal
tidal height than
than for clams
clams planted on non-vegetated areas
areas higher
higher
on the
the tideflat,
tideflat.
And progeny from
"fast" growing adults grew
grew faster
faster than
than clams
clams
from "fast'
spawned from "normal"
"normal" size
size adults.
adults.
9.
9.
Manila clams
in Tillamook,
Tillamook, Alsea,
Alsea, Coos
Coos and
and Coquille
Coquille bays
bays failed
failed to
to
Manila
clams planted in
survive.
survive,
Inadequate
release sites
Inadequate substrate
substrate material
material and
and instability of the release
are thought to
to have
have been the
the major causes of the loss
loss of clams.
clams.
are
-18-18-
APPENDIX
APPENDIX
(Figures AA through
through F)
F)
(Figures
.l(f(~
l\jt=y\jr--UKt
(
..."
~.
<Q
(0
illj
c:
....ro
-
i
-11
2
_'
n6fTi
~"
.
"~
(C
II
IN
:P
\) I
r
r
oo
o
()
'"r+
cv
I
~.
oo
::s
I
/
oo
/~'J
'-,
-h
.
"
rn,
><
-0
-Q
....roS
CD
~.
B
~
CD
1
::s
YQ\uif\o..
z
Z
r+
ci-
~
<
;:;
'"32
u
'"
eQl
~I
' l!
o
n
I
'.'
>-'
\D
,
\-l-
-0
-o
~
"j
U
cv
:::J
'"r+
.,
/
<!.
~
'"
U,
-<I
fl'"c:C
C
-<
cv
I
.D
~.
::s
'"co
(C
'<
'"
cv
cv
>-'
'"
'"
00
I
.....,
N
Na
11
22
33
4
4
5S
6
6
7
8
!
99
1 10
10
! 11
11
I
I
I
t
------
Butter
Butter
Butter
Butter
Manila
Manila
t~anila
Manila
Manila
Manila
Manila
Manila
Manila
Manila
Manila
Native
Native
Native
Native
Gaper,
Gaper,
clam, artificial
artificial substrate,
substrate, 12/68.
12/68.
clam,
clam, natural
natural substrate,
substrate, 3/70.
3/70.
clam,
LN, suitability
suitability of
of area,
area, 5/70.
5/70.
LU,
LN, size-density,
size-density, 10/71.
10/71.
LU,
LN, size-density,
size-density, 4/72.
4/72.
LU,
LN, suitability
suitability of
of area,
area, 10/72.
10/72.
LU,
LN, suitability
suitability of
of area,
area, 7/72.
7/72.
LU,
LU,
LN, suitability of area,
area, 7,
7, 99 && 10/72.
10/72.
LN, artificial
artificial substrate,
substrate, 9/70.
9/70.
LU,
LN, suitability
suitability of
of area,
area, 6/72.
6/72.
LU,
suitabi 1ity of
of area,
area, 9/70.
9/70.
suitability
7
Fl
5
"-----.,-~
~----~:
-20-20-
1 -- Manila
- Manila
r~anila
2 33 - Manila
r~anila
4 - Manila
4
5 - Manila
r1anila
- Manila
6 7 and 8 - Manila
- Manila
9 10
11 - Manila
10 and 11
12
12 -- r~anila
Manila
-.
\\
LN,
[N,
LN,
[N,
LN,
LN,
LN,
[N,
LN,
LN,
LN,
[N,
LN,
LN,
LN,
LN,
LN,
LN,
LN,
[N,
of area,
area, 9/71.
9/71.
suitability of
suitability of
of area,
area, 7/73.
7/73.
suitability
suitability of
of area,
area, 7/73.
7/73.
suitability
suitability of
of area,
area, 7/73.
7/73.
suitability
suitability of
of area,
area, 7/73.
7/73.
suitability
suitability of
of area,
area, 7/73.
7/73.
suitability
fenced
fenced vs.
vs. unfenced,
unfenced, 6/74.
6/74.
6/74.
eelgrass, 6/74.
fast vs.
vs. slow
slow growth,
growth, 8/74.
8/74.
fast
mass plants,
plants, 10/74.
10/74.
ETATS
NETA'RTS
I
z
«
LU
g
(j
/1.
lJ'T.
(f
Lz1p
10&11
o&u
6
2
Ne1-arfsBay
Net~rrs
'BlAY
I
=nno
¥&_
I
IOOd
Figure B.
B.
'"
N
N
a
0
taCO
/006
:JOex>
COO ~
zc 100<1
tOoo 4'"000
C000
'PVE.eT
tT
Location of Experimental
Experimental Clam Plants, Netarts
Netarts Bay,
Bay, 1971-74.
1971-74.
Location
-21-21
1illlilmook &y
""
N
1 -- Manila Littleneck
Littleneck clams,
clams,
suitabil ity of
of area,
area, 9/71.
9/71.
suitability
1000 0
G60
1000 flOt
TilLAMoOK
TILLAMOoc
Figure C.
C.
Location of
of Experimental
Experimental Clam
Clam Plant,
Plant, Tillamook
Tillamook Bay,
Bay, 1971.
1971.
Location
-22-
.4/
3
(
c
if L_y
c:
/7
N
V
-
--_\
,-
7
//
\
\
'
'L
'\
\
N\
:
N
4
':
\
Li
Li
,
0
I
c.-2
Li
C-
1
I
\
If
\
i
\
I
-2
I
1 -- r·1anila
littleneck clams,
clams,
1
Manila littleneck
suitabil ity of
of area,
area. 10/71.
10/71.
suitability
U
I
I
I
\
2 and
3 -- Manfla
Manila littleneck
littleneck clams,
clams,
2
and 3
suitability of
of area,
area, 6/72.
6/72.
Abea Thy
xl
Figure
D.
Figure 0
Location
Experimental Clam Plants,
Alsea Bay,
Bay, 1971-72.
1971-72.
Location of Experimental
Plants, Alsea
-23-23-
11 and
M
. a littleneck
aml
lit·
and 2
2 -- suitabil'ittleneck
Manila
clams,
clams
y of area, 8/:h.
-$
'V.)
r.
r-4
Ul
01
o0
o0
u
C-)
OD
4-)
C
r
CE
(Es
IC-)
(E$
4)
ci
ci
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II
C
Co
1 -- Manila
littleneck clams,
clams,
Manila littleneck
suitability
of area,
area, 8/73.
8/73.
suitability of
Pad f Ie
Pad
ic
Ocean
)
North
Spit
0
>
I
/
14R
/
1
Bard c)ri
Figure F.
Figure
F.
Location
Bay, 1973.
1973.
Location of
of Experimental
Experimental Clam
Clam Plant,
Plant, Coquille
Coquille Bay,