CLAM-OYSTBR-ABALONE
CLAN-OYSTER-ABALONE LARVAL REARING
July 1,
l~
July
ANNUAL REPORT
1970 to
to June
June 30,
30, 1971
1971
1970
Gerald T.
Lukas
Gerald
T. Lukas
Gary G.
G. Gibson
Fish Commission of
of Oregon
U.S. Department
Department of
of Commerce
Commerce
U.S.
National Oceanic and Atmospheric Administration
Fisheries Service
Service
National Marine Fisheries
Commercial
and Development
Development Act
Commercial Fisheries
Fisheries Research
Research and
Act
Subproject
Subproject l-60-R-1
l-60-R-l
Contract No.
14-17-0001-2329
Contract
No. 14-17-0001-2329
July 1971
1971
July
TABLE OF CONTENTS
CONTENTS Page No.
No.
Page
INTRODUCTION.
INTRODUCTION
11 CLAM
CLAM STUDIES.
STUDIES
.
Methods •
• •
• • • • •
Spawning
and Larval
Larval Rearing
Rearing of
of Clams
Clams .•
Spawning and
Field Studies
• . • ........................
. . . • . • . .
Field
Studies
littleneck clams
clams ...............
. • . . . . . • . .
Manila
Manila littleneck
littleneck clams
clams •..............
.
Native
Native littleneck
Gaper clams • . .
Gaperclams....................
Butter
clamsclams
• . . . .....................
•.
Butter
Results . . . . . . . . ,
. ...... . . . . . . .
Spawningand
andLarval
Larval
Rearing
of Clams
Spawning
Rearina
of Clams
••. ..........
.
.
.
.
.
,
.
.
.
Fie
Id Studies
. . . . . . • . • • •
Field
Studies ......................
.
Manila Ii ttleneck
clams clams
• .
Manila
littleneck
..............
littleneck clams
clams ...............
. . • .
Native littleneck
Native
Gaper
clams
.
•
.
.
•
.
.
.
Gaperclams....................
ButterClams
Butter
Clams • . • •....................
...
Discussion and
and Conclusions
Conclusions
Discussion
Spawning
Rearing
of Clams.
Spawningand
andLarval
Larval
Rearing
of Clams ..........
Field
Studies • • • •.....................
• • ••
• •
FieldStudies
Manila
littleneck
..............
clams clams
.
Manila littleneck
Native littleneck
clams clams
•
Native
littleneck
..............
Gaper
clams
•
.
Gaperclams....................
Butter clams. .
Butterclams....................
OYSTER
STUDIES. • • • •.........................
.
OYSTERSTUDIES
Me thod.s .
Methods
. • .........................
. . . . . .
Spawning
Rearina
of Clams.
Spawningand
andLarval
Larval
Rearing
of Clams ..........
Field Studies • . • ......................
. . . • . • • •
FjejdStudjes
Spat Spat
.
Imported vs.
Imported
vs.Laboratory-Reared
Laboratory-Reared
........
at at
Different
Depths.
Tray
Tray Culture
Culture
Different
Depths ..........
String
TrayTray
Culture
.
Stringvs.vs.
Culture
..............
Winter
Spat
Survival
• • • . .................
•••
Winter
Spat
Survival
Resul
ts . . . . . . . . . . . . . . . . . . .
Results..........................
Field
Studies
. . • . .....................
. • . • . • . •
Field
Studies
Imported
Spat Spat
.
Importedvs.
vs.Laboratory-Reared
Laboratory-Reared
........
at at
Different
Depths
..
Tray
Tray Culture
Culture
Different
Depths
..........
String
TrayTray
Culture
.
Stringvs.vs.
Culture
..............
. • • • •................
.•.
Winter
Spat
Survival
Winter
Spat
Survival
Discussion
and and
Conclusions
.•.••.
.••.••.
Discussion
Conclusions
.................
Fie
Id Studies . • • •.....................
. . • • • • . . • . . • . • . • •
FieldStudies
Spat Spat
...•
.
Imported
Importedvs.
vs.Laboratory-Reared
Laboratory-Reared
........
Tray Culture
Different
Depths
. . . ..........
Tray
Cultureat at
Different
Depths
String
TrayTray
Culture
Stringvs.vs.
Culture ..............
Survival.
Winter
Spat
Winter
Spat
Survival ................
1
1 11 11 2
2
2
2
2
2
2
2
2
2 2
2
2
2
3
3
3
3
5
S
5
66 66 66 6
6
6
6
7
7 7
7 7
7
7
7
7
7 7
7 7
7 88 8
8
9
9
9
9
10
10 10 11
11 12
12 12 12
12 13
13 13
13 14
14 ABALONE STUDIES . •
ABALONESTUDIES
........................
14
14 Methods . . . ..........................
Methods
Results
•. Results..........................
14
14 15
15 15
15 Discussion.
Discussion
.........................
PROGRESS TOWARD OBJECTIVES.
.
PROGRESS
OBJECTIVES ...................
LITERATURE CITED. CITED
• . • . ........................
. .
LITERATURE
15
15 16
16 LIST OF TABLES
Table No.
No. 11 2
2 33 4
5
5 6
77 8
Page No.
No.
Length and
and Percentage
Percentage Survival
Survival of
of Ilanila
HanUa Mean Shell Length
Clams
Experimental
ClamClam
Bed. Bed......
. . • • .
Clams Planted
Plantedininanan
Experimental
4
Growth and Percentage Survival of
of Native
Nativ.e Littleneck
Littleneck Clams
After
Planting.
• . . ............
• • • • •
Clams7 7Months
Months
After
Planting
4
4
Growth and Percentage Survival of
of Butter
Butter Clams
Clams at
at 15
{\ionths
After
Plan ting
• . . . ...........
• • .
15 and
and2424
Months
After
Planting
5
5 (mm) and Volume of Imported and Length and Width (mm)
Hatchery-Reared
Pacific
Oysters
• . . ...........
.•••• .
Hatchery-Reared
Pacific
Oysters
99 (mm) of
of Imported
Imported and
and HatcheryHatchery­ Length and Width (mm)
Reared
Oysters
....•
........
RearedKumamoto
Kumamoto
Oysters
...............
10
10 Shell Growth (Length
(Length Width mm)
II1II) of
of Pacific
Pacific Oysters
Oysters Reared in Suspended Trays,
in
a
Stationary
Intertidal Trays,
Tray
. ., . . . . . . . . . . . . . . . . . . . . . .
Tray........................
10 Shell Growth (mm)
(mm) of Pacific Oysters Cultured on Strings (Rack
(Rack and
and Boom
Boom Log)
Log) and
and in
in aa Suspended
Suspended Tray.
Tray.
11
11 Winter Survival of Laboratory-Reared Pacific Oyster Spat Planted at Different Ages
Ages and Times in Yaquina AprilApril
1971) 1971)
. • . • ..............
• • • • • • • . • •
Bay (Sampled
Bay
(Sampled
11 11
LIST OF FIGURES
Page No.
No.
Figure 11o.
Fisure
No.
1
1 (Length Times Width)
Width) vs.
VS. Meat Mean Shell Size (Length
(Shucked Count Per Quart)
Quart) of Four
Four Groups Volume (Shucked
of
Pacific Oysters . . . . .................
• . • . . . • • • . •
ofPacificOysters
2
2 (Length Times Width)
Width) vs.
vs. Meat
Mean Shell Size (Length
(Shucked Count
Count Per
Per Pint)
Pint) of
of Three
Three Groups
Groups
Volume (Shucked
..
of
Oysters
. . • . ..................
....•....•
of Kumomoto
Kumomoto
Oysters
12
12 13 CLAM-OYSTER-ABALONE
CLAI.1-OYSTER-ABALONE LARVAL
LARVAL REARING
REARING
INTRODUcrION
Clam studies
studies in the laboratory during the 1970-71 project year con­
con-
and larval
larval rearing
rearing of
of several
several species.
species.
tinued with the spawning and
Fie
ld
Field
studies were initiated utilizing
utilizing laboratory-reared
laboratory-reared juvenile
juvenile clams.
clams.
These
clams
clams were
were planted
planted in
in experimental
experimental plots
plots and
and monitored
monitored for
for growth
growth and
and
survival.
Monitoring continued on experimental clam plot studies
studies initiated
during the previous report
report period.
period.
during
Field studies
studies comparing growth
growth and survival of laboratory-reared and
imported Pacific
Pacific and
and Kumamoto
Kumamoto oysters
oysters were
were completed.
completed.
We continued
continued studies
comparing various
methods of
of oyster
oyster culture
culture in
in Yaquina
Yaquina Bay.
Bay.
various methods
Winter
Winter sursur­
vival of
of laboratory-reared
laboratory-reared oyster
oyster spat
spat was
was determined.
determined.
vival
Adul t red
red abalone
abalone were obtained
obtained for
for spawning
spawning purposes.
purposes.
Adult
During the
the project year~
year, Duane
Duane Phibbs,
Phibbs, the
the project
project biologist,
biologist, resigned
resigned
to go into private business.
This resulted in some delay in project
activities.
CLAM STUDIES
Methods
Spawning
pawning and Larval Rearing of Clams
Several clam species
juven­
species were
were spawned in the laboratory to provide juvenile clams
clams for
for field
field studies.
studies.
These included gaper (Treeue
(TzoeSU8 capax),
capaa:) ~ native
(Tapes 8elflilittleneck (Protothaca
littleneck (Tapes
semi­
(Pxatothaca staminea),
etaminea), and Manila littleneck
decussata) cl
clams.
deauseata)
ants,
Razor clams
clams (SiUqua
patuZa) were induced to spawn by using KC1
KCl and
(Siliqua patula)
allowing the water to
to warm to
to 17-18
17-18 CC (Phibbs,
(Phibbs, 1968).
1968).
Razor clam larvae
were reared through metamorphsis and the resultant set placed in sand.
sand.
sea water,
water. drawn
drawn from
from the
the bay,
bay, was
was circulated
circulated through
through the
the tank.
tank.
Untreated sea
2. We
attempted to
We attempted
to spawn
spawn geoduck
geoduck (Panope generosa)
cl ams but
adul t
generoea) clams
but the
the adult
stock had
priorto
to our
our collecting
stock
had spawned
spawned prior
collecting them.
them.
Studies
Field Studies
Manila
clams.
Manila littleneck
littleneck clams.
Juvenile Manila
littleneck clams
clams reared
reared in
in
Juvenile
1anila littleneck
the laboratory
laboratory and
and planted
plantedininIIay
Hay1970
1970 (Phibbs,
(Phibbs ~ 1970)
1970) were
were sampled
sampled four
times
year.
times during
during the
the project
project year.
These
average length
These clams~
clams,with
with a~
an average
length of
nun, were
in upper
upper Yaquina
Yaquina Bay
3 nun,
wereplanted
plantedinin an
an 88 by
by 2S-foot
25-foot plot in
Bayatat aa
density
20 per
square foot.
density of
of 20
per square
Native littleneck
clams. In
September 1970
Native
littleneck clams.
In September
1970600
600juvenile
juvenilelittleneck
littleneck
clams
sub­
clams\~ere
wereplanted
plantedinin prepared
prepared clam
clambeds
bedscontaining
containingseveral
several types
types of sub-
strate.
strate. These
juvenileswere
wereapproximately
approximately11
11months
months
These laboratory-reared
laboratory-reared juveniles
old and
shell length
and had
had a mean
mean shell
length of
of9.9
9.9mm.
mm. They
They were
wereplanted
plantedatat the
the rate
100 per
in 66 plots
plotseach
each measuring
measuring 44 by
Five of
of the
the plots
of 100
per plot in
by 44 feet. Five
contained
mixed into
containedgravel
gravelof
of various
various sizes
sizes mixed
into the
the substrate.
substrate.
One
plot was
One plot
was
left
l.mdisturbed and
and served
left undisturbed
served as
as aa control.
Gaper clams. Three
Three thousand
laboratory-rearedgaper
gaperclams
clams
Gaper
thousand juvenile
juvenile laboratory-reared
an 88 by
by 15-foot
IS-footexperimental
experimental plot
plotininYaquina
YaquinaBay.
Bay. These
were planted
were
planted in an
clams
clams averaged
averaged 13.6
13.6 mm
nunshell
shell length.
length.
They
in Septnieber
Septmeber 1970
1970
They were
were planted
planted in
an area
area which
which contained
contained aa natural population
population of
of adult
adultgaper
gaperclams.
clams.
in an
clanlS. Monitoring
clams
Monitoringof
of growth
growthand
andsurvival
survival of
of butter
butter clams
Butter clams.
in prepared
prepared plots
plotsininYaquina
YaquinaBay
Bay continued.
continued. These
These laboratory­
laboratoryplanted in
reared juvenile
juvenileclams
clams were
were planted
plantedininDecember
December 1968
1968 (Phibbs,
(Phibbs I 1969).
1969).
Resul ts
Results
Spawning
of Clams
Clams
Spawningand
and Larval
Larval Rearing of
Manila
clams were
were successfully
successfullyspawned
sp81med and
and the
Manila and
andnative
native littleneck
littleneck clams
the
resultant
juveniles are
are currently
currently being
being held
held in
in laboratory
laboratory tanks.
tanks.
resultant juveniles
The
3.
Manila juveniles will be planted in several bays
bays which offer suitable
suitable
habitat and will be monitored periodically to evaluate survival
survival and grOt/th
growth
selected areas.
areas.
in these selected
The juveniles
juveniles from the gaper clam spawning suffered high mort
ali ties
mortalities
while being held in the laboratory
laboratory due
due to
to lack
lack of
of food.
food.
The juvenile razor clams
clams also experienced high mortalities
mortalities while being
held in the laboratory.
Approximately 5 months after spawning only seven
juveniles survived
survived and
and averaged
averaged 5.2
5.2nun
mm in
in length.
length.
juveniles
mortalities
The high mortalities
experienced by the
juveniles probably
the juveniles
probably resulted from extremely low salinities
salinities
(2-4 0/00)
during the
the 5-month
5-month winter
winter period.
period.
(2-4
o/oo) which
which occurred periodically during
Before further attempts
clams, laboratory equipment
attempts are
are made
made to rear razor clams,
equipment
will be designed which will monitor the salinity of the incoming water and
automatically shut off
off the
the water
water when
when salinity
salinity decreases
decreases to
to critical
critical levels.
levels.
Field Studies
i'ianila
clams. The survival of
of the Manila
Manila littleneck clams
Manila littleneck clams.
in the experimental plots varied
varied according
according to
to the
the type
type of
of substrate
substrate (Table
(Table 1).
1).
During the 12-month
l2-month period a river gravel substrate produced the best sur­
survival while gravel-mud
gravel-mud substrate
substrate was
was poor.
poor.
total mortality after
after only
only 33 months.
A mud
rod substrate resulted in
A
The clams grew well through October
1970
1970 but
but during the winter and spring period
period growth
growth was
was curtailed.
curtailed.
However,
the total growth
growth of
of 18.4
18.4 umi
DIll during
the plot
plot is
is
during the
the year
year the
the clams
clams were in the
believed to
to be
be above
above average.
average.
believed
Native littleneck
littleneck clams.
clams.
Native
The juvenile littleneck clams
clams planted in
an artificial
artificial bed
bed containing various
various types
types of substrate
substrate were
were sampled for
for
growth
growth and survival 7 months after planting.
The average length of
of all
clams
sampled was
was 12.8
12.8 mm,
mm, an
an increase
increase of
of 2.9
2.9 nun
un in
7 months.
clams when sampled
in 7
months.
There
4.
4.
Table 1.
1. Mean Shell Length
Length and Percentage Survival
Survival of Manila
Manila
Clams
Clams Planted in an ExpArimental
Experimental Clam Bed
led
Date Surp
Sampled
8-18-70
8-18-70
10-28-70
1-7-71
1-7-71
5-14-71
Mean Shell
Length (mm)
(mm)
Length
Percentage Survival
Percentase
River
Ri ver Gravel
Gravel River Gravel-Mud
12,0
12.0
19.1
19.6
21.4
12.5
12.5
7.5
7.5
4.6
10.0
15.0
2.5
2.5
0.8
Mud
0
0
0
0
0
0
00
were some differences in growth of clams
clams between the
the different
different plots
(Table
plots (Table
2).
However, some of the plOts
plots yielded very few clams so average shell
lengths
may not reflect
reflect the
the actual
actual average
average growth.
growth.
lengths of the samples may
Table 2.
2.
Table
Plot
No.
Growth and Percentage Survival of Native Littleneck
Littleneck
Clams 7 ~1onths
Months After Planting
Substrate
Type 11
1/
Mean Shell
(mm)
Length (mm)
Percentage
Survival
11
Control
(unchanged)
12.5
2.0
22
Crushe
d Rock
Crushed
3/4"-1 l/2'
1/2"
12.6
42.0
33
River Rock
Rock
3/4" minus
14.0
4.0
4
4
Crushed Rock
Rock
3/4l
3/4" minus
minus
13.0
6.0
6.0
S
5
River Rock
3/4 11 -1 1/21!
3/4"..l
1/2"
12.0
2.0
66
Crushed Rock
1 l/2"-3"
1/2 H -3"
13.7
8.0
(1969) •
Substrate described
desoribed by
by Phibbe
Pnibbs (1969).
1/ Substrate
Y
Only one type of substrate,
gravel, had a
substrate, 3/4-1 1/2 inch crushed gravel,
significantly high survival rate.
rate.
problem during
during the
the 7-month
7-month interinter­
One problem
val the clams were in the plots was the deposition of silt.
The results
results
are therefore probably not conclusive
conclusive as
as clams
clams in
in the
the various
various gravel
gravel plots
plots
are
5. might
the plots
plots were
were in
in an
an area
area where
where sil­
mighthave
haveshawn
shcnbetter
better survival
survival if
if the
siltation
had not
not occurred.
occurred.
tation had
Gaper clams. The
gaper clams
clams planted
plantedininSeptember
September1970
1970 were
were
Gaper
The juvenile gaper
sampled 11 month
No clams
fomd. This
This planting was
was a
sampled
monthlater.
later. No
clams could
could be
be found.
second
laboratory-reared juvenile
juvenile gaper
gaper clams.
clams.
second attempt
attemptto
to plant
plant laboratory-reared
The pre­
The
pre-
vious
made inin 1969
total mormor­
vious attempt,
attempt, made
1969(Phibbs,
(Phibbs,1969),
1969),also
alsoresulted
resulted in
in aa total
tality.
tality.
The probable cause
cause was
and
was prolonged
prolonged exposure
exposure during
during low
low tides
tides and
predators.
The second
was made
which contained
second planting
planting was
madeinin an
an area which
contained aa
natural population
population of
gaper clams
clams and
of adult gaper
andwas
wasatataa lower
lowertide
tide level.
The total
mortality was
was believed to have
have resulted
resulted from
from predation
predation by
by crabs.
The
total mortality
clams. Juvenile
Juvenile butter
butter clams
clams in
in the
the experimental
experimental plots
plots were
were
Butter clams.
in December
December 1970.
1970.
sampled
sampled in
They
They grew
grewananaverage
averageof
of 14.7
14.7 mm
nunininshell
shell length
in aa 9-month
9-month period
(Table 3).
period (Table
Table
Clams at
Table 3. Growth
Growthand
andPercentage
PercentageSurvival
Survival of
of Butter Clams
15
and 24
24 Months
15 and
MonthsAfter
After Planting
Planting
Plot
No.
1I Type
Gravel Type
and Size
and
Control
March 25,!
1970
25, 1970
t4ean
MeanShell
Shell Percentage
Length (mm)
(mm)
Survival
1970
December
December 9,
9, 1970
Mean
Shell Percentage
Mean Shell
Survival
Surviva1
Length (mm)
(nunl
26.3
26,3
0.2
2/
Y
0.2
(mchanged)
(unchanged)
2
Crushed
3/4"-1
l/2'
3/4"-1 1/2"
24.2
20
2.0
38.6
0.7
07
33 River
3/4U
3/4 11 minus
minus
23.8
0.5
41.0
0.4
4
Crushed
3/4'1 minus
minus
3/4"
23.8
4.5
38.6
3.3
5
S
River
3/4"-1
3/4 10 -1 1/2"
1/2"
23.3
0.9
35.6
0.7
07
Crushed
1.
1/2"-3'
1 1/2"-3"
22.2
2.4
38.2
382
2.5
6
------------------------------------Total
Total Plot
Average
y
2/
Sample
Scvnpie
23.5
broken~
br'ken,, unmeasurabte.
unmeasurable.
1.8
38.2
1.2
6. Survival in plot number four was
was the
the highest
highest of all
all plots
plots but
but mortal­
mortality between March and December
DeceDber 1970
1970 in
in plot
plot four
four was
was greater
greater than
than the
the
average.
Plot number six with the next
next highest
highest survival
survival rate
rate did not
experience any mortality during the March to
to December
December period.
period.
The increase
increase
The
in survival in December was the result of
of sample
sample variation.
variation.
Discussion and
and Conclusions
Conclusions
Spawning and
and Larval
Larval Rearing
Rearing of
of Clams
Clams
The continued success
Iittleneck and
success in laboratory rearing of native littleneck
Manila littleneck clams has been encouraging.
encouraging.
of these
these
An adequate supply of
juveniles is
juveniles
is needed for
for field
field studies
studies to determine
determine the
the best
best size
size and time
time
of year of planting for maximum survival.
survival.
Although stripping the
the sex
products from gaper clams has been successful, there is a greater chance
of obtaining malformed
malformed and
and immature
immature eggs.
eggs.
of
More work needs
needs to be done on
the
the technique
technique of inducing the
the adult
adult gapers
gapers to spawn
spawn naturally.
naturally. The
The poor
poor
survival of juvenile razor clams was assumed to have resulted from low
occurred during
during winter.
winter.
salinities which occurred
Further attempts will be made
made
to rear razor clams
tor the
clams and to mom
monitor
the incoming water
water and prevent
prevent exposure
exposure
of the juveniles to
to low
low salinities.
salinities.
of
Field Studies
Studies
Field
iai1a
littleneck clanis.
~';~1~.~~_!!~t1eneck
clams.
shown good
The juvenile Manila clams have ShO\,ffi
the year
year they
they were
were in
in the
the experimental
experimental plot
plot in
in upper
upper Yaquina
Yaquina Bay.
Bay.
growth during the
growth
The survival of 4.6% in the gravel substrate may be typical but no
data are available for comparison.
comparison.
Native littleneck
littleneck clams.
clams.
Native
field studies
studies are
are planned.
planned.
Additional field
Juvenile littleneck
littleneck clams
clams shcMed
showed exceptional
survival
3/4-1 1/2
1/2 inch crushed rock probably
survival in the
the substrate consisting of 3/4-1
because water current in this area kept the plot free of
of silt.
silt.
Growth of
7. 2.9
nm
Jl1ll in 7 months is probably about average
average for
for aa winter
winter period.
period.
Sur­
Sur-
vival in the
the other plots
plots might
might have been higher if silt deposition had
had
not occurred.
Gaper
Gaper clams.
clams.
again.
again.
juvenile gaper
gaper clams will be attempted
The planting of juvenile
Screen will be used
used to
to cover
cover the
the clam
clam plot
plot to
to keep
keep predator
predator crabs
crabs
out.
Butter clams.
clams.
Juvenile butter clams continued to have the best sur­
sur-
vival
vival in a plot containing l/4-inch
3/4-inch minus
minus crushed gravel which
which closely
habitat.
approximates natural habitat.
enced good
good survival.
survival.
Clams
experi­
Clams in crushed 1 1/2-3 inch gravel experi-
are part of
of the same habitat study as
These plots are
the littleneck
Iittleneck clam
clam study.
study.
Butter clam survival may have been affected by
siltation,
fUture experimental
siltation, a factor that
that will
will be
be considered in future
experimental clam
plots.
plots.
OYSTER STUDIES
Methods
Spawning and
and Larval
Larval Rearin.g
Rearing
Spawning
Oyster spawning and larval rearing activities
acd vi ties have been phased out of
this program
program and
and are
are nnow being done on aa routine basis by Oregon State
this
Universi ty personnel in
in their
their pilot
pi lot oyster
oyster hatchery
hatchery at
at Newport.
Newport.
University
Field Studies
I!'P0rted
Laboratory-Reared Spat.
Imported vs.
vs. Laboratory-Reared
The study comparing growth
growth and
survival of
of imported
imported and
and laboratory-reared
laboratory-reared Pacific
Pacific and
and Kumainoto
Kumamoto oyster
oyster
spat in Yaquina
Yaquina Bay
Bay was completed.
completed.
In .May
1969 spat of
of Pacific
Pacific oysters
oysters
May 1969
spawned in
in June-August
June-August 1968
1968 and
and spat
spat from
from Kumainoto
Kumamoto oysters
oysters spawned
spawned in
in
September-December 1968 were placed in trays
trays suspended from an oyster
raft in
in Yaquina
Yaquina Bay.
Bay.
rearing raft
Imported Japanese seed was planted
planted at
at the
the
8. $ mne time,
time, place,
p lace, and
and in
in the
the same
same manner.
same
manner.
Random measurements (length
(length
and width of
of 40
40 oysters
oysters from
from each
each tray)
tray) were
were taken
taken at
at planting
planting and
and periperi­
and
odically until
until Decenther
December 1970
shucked to
to
1970 when
when samples
samples of
of oysters
oysters were shucked
determine oyster count per
per unit
unit volume.
volume.
This was done to test whether
whether
shell length-width measurements
(meat
measurements accurately indicate oyster size
size (meat
volume).
determined by
by gross
gross examination
examination of
of the
the cuitch.
cultch.
Survival was determined
Tray Culture at Different Depths.
Depths.
Laboratory-reared
Lab
oratory-reared oysters
oysters cultured
cultured
off bottan
bottom in a stationary intertidal
intertidal tray,
tray, and in suspended trays
trays at
at
various
(3, 6,
various depths
depths (3,
6, 9,
9, and l2-feet
12-feet below
below the
the water
water surface)
surface) were
were monitored
monitored
for growth and survival.
for
Random samples of oysters
(length and width of
oysters (length
40 oysters
oysters from
from each
each tray)
tray) were
were measured
measured every
every 33 months.
months.
40
21 months of
At 21
age
(June 1971)
1971) samples
samples of
of oysters
oysters will
will be
be shucked
shucked to
to determine
determine meat
meat volume.
volume.
age (June
String vs.
vs. Tray
Tray Culture.
Culture.
Growth and survival experiments
experiments with Pacific
oyster spat
(cultch separated
spat (cultth
separated by
by 6-inch
6-inch plastic pipe
pipe spacers)
spacers) on
on wire
wire
strings was continued
continued in
in Yaquina
Yaquina Bay.
Bay.
strings
Some of these 8-foot strings were
log; others were draped over a wooden rack.
suspended from a boom log;
rack. Additional
spat of
of the
the same
same brood
were suspended
suspended from
from the
the oyster
oyster raft
raft in
in aa tray.
tray.
spat
brood were
Quarterly samples were taken to compare growth and survival of those animals
animals
tidal fluctuations
fluctuations (rack
(rack strings)
oysters continuously subsub­
exposed by tidal
strings) and oysters
merged (log
(log boom
boom strings
strings and
and trays).
trays).
Winter Spat Survival.
A study to determine winter survival of
A
laboratory-reared oyster spat was completed
completed in
in Yaquina
Yaquina Bay.
Bay.
Four broods
of oyster spat,
spat, set
set in
in August-October
August-October 1970
1970 and in
in January
January 1971,
1971, were
were planted
planted
in aa suspended tray at various
from September
through February
February
various ages
ages from
Septenber 1970 through
1971
to determine survival.
survival.
1971 and counted in April 1971 to
9. Results
Field Studies
Studies
Imported
Laboratory-Reared Spat.
Imported vs.
vs. Laboratory-Reared
Mortality
groups of
Mortality in
in all
all groups
Pacific oysters
oysterswas
was negligible
negligibleexcept
exceptamong
among those
thoseanimals
animals from
from the
theAugust
August
Pacific
spawning.
August spat
on which
August
spatwere
werecollected
collectedon
onscallop
scallopshells
shells on
whichsilt
silt
settled
andsmothered
smothered about
about 50%
50% of
young oysters.
settled and
of the young
After 19
19 months
months of
growth, hatchery and
and imported
of growth,
importedPacific
Pacific oysters
averaged the
sizeand
andininmeat
meatvolume
volume (Table
(Table 4).
averaged
the same
sameboth
bothin
in shell
shell size
Hatchery oystelS
fromJune's
June'sspawning
spawning were
shell size
size and
and
Hatchery
oystefrxi
were the
the smallest
smallest in
in shell
July's spawning
meat volume
spawning was
was
meat
volumeofofall
all groups
groups (highest
(highest count
count per
per quart). July's
.the
the largest.
Tab Ie 4. Length
Width (mm)
(mm) and
and
Table
Length and Width
and Volume
Volumeof
of Imported and
Hatchery-Reared
Oysters
Hatchery-RearedPacific
Pacific Oysters
Month
Sampled
Hatchery Spawning
S~awnini Date
Date
8-13-68
6-5-68
7-29-68
May
May 1969
8-7
18-15
46-33
61-52
65-45
72-54
92-65
95-65
7-5
19-17
53-39
66-48
71-48
81-57
108-71
114-77
40
26
June
September
December
March
1970
March 1970
~1ay
May
SepteJdJer
September
December
Shucked
Shucked Oyster
Oyster
Count Per Quart
Quart
Count
Imported
Spawning
s§awnin~ Date
ummer 1968
Summer
5-4
12-12
44-40
61-44
62-54
75-66
97-76
99-78 (Mean
(Mean
103- 73)
103-73)
30 (Mean
(Mean 32)
32)
30
7-5
18-14
5434
54-34
67-48
73-51
85-60
110-73
113-72
32
20 months
months of growth,
growth, imported
imported Kuniainoto
Kumamoto oysters
After 20
oystersaveraged
averagedslightly
slightly
in shell
shelllength
length(4.5
(4.5
nun)and
andwidth
width(5.5
(5.5mm)
mm) than
than laboratory
laboratoryprogeny
progeny
smaller in
mm)
but produced
produced aa 9%
9% greater
meat volume
(Table 5).
greater meat
volume(lowest
(lowest count
count per
per pint) (Table
Mort
ali ty was
was negligible
both groups.
groups.
Mortality
negligible in both
10.
Table 5.
5. Length and Width (mm)
(mm) of
of Imported
Imported and
and HatcheryHatchery­
Reared Kumamoto Oysters
Month
Sampled
Sam:e 1ed
Hatchery Spawning
SEawnin& Date
Date
9-23-68
12-17-68
April 1968
July
October
January 1970
1970
May
September
December
3-3
30-26
45-37
46-38
48-41
55-43
56-44
Shucked Oyster
COWlt
Count Per Pint
91
Tray Culture at
at Different
Different Depths.
De:eths.
Imported
Spawning
SEawnin& Date
Summer
Stunner 1968
1968
8-7
8-7
30-26
48-38
47-39
53-41
59-45
59-45
5-4
22-19
41-33
40-32
43-34
53-40
53-39
90
82
Shell growth
growth of
of Pacific
Pacific oysters
oysters
19
Yaquina Bay
Bay was better
better in
in suspended
suspended trays
trays
19 months
months after planting in Yaquina
than in the
tray (Table
(Tab Ie 6).
6).
the stationary intertidal tray
trays
depths tested,
tested.
trays was
was nearly the same at all depths
Growth in suspended
Mortality
l-Jortali
ty in all of
of the
the
trays was negligible.
Table 6.
6. Shell
Shell Growth
Growth (Lenth-Width
(Length-Width
nm) of Pacific Oysters
nzii)
Trays# in a Stationary Intertidal
Intertidal
Reared in Suspended Trays,
Tray
Date
September 1969
October
December
January 1970
r.1arch
March
June
JWle
September
December
April 1971
3 Feet
22
9-7
15-13
15-13
15-13
15-13
19-16
19-16
42-34
69-52
80-56
85-59
Trays (Depth)
Suspended
(De:ethl
SusEended Trars
9 Feet
6 Feet
Feet
2
2
10-9
18-16
19-15
23-19
42-32
67-50
77-57
88-64
vs. Tray
Trar Culture.
String vs.
2
2
9-8
16-14
16-14
23-20
44-35
73-51
73-51
81-53
85-63
12 Feet
22
9-8
17-15
17-15
27-22
48-37
73-47
83-58
89-65
Stationary
Intertidal
Tray
Tr!l
22
6-5
--
10-8
15-13
27-23
57-47
60-43
62-47
Shell growth, 13
13 months after
after planting,
planting,
was slightly better in
in the suspended
suspended tray
tray than
than on
on strings
strings (Table
(Table 7).
7).
Oysters on the rack string were
the three groups'tested.
were the smallest of the
groups tested.
11.
Table 7.
7. Shell Growth (mm)
(mm) of Pacific Oysters Cultured on
Strings (Rack
(Rack. and Boom Log)
Log) and in a Suspended Tray
Date
3-70
7-70
7-70
11-70
1-71
4-71
Rack.
Rack Strings
Boom
Strings
Boom Log
1g Strings
3.5
18.2
45.1
45,1
51.3
58.1-44.5
Winter Spat
Spat Survival.
Survival.
Winter
3.5
27.3
61.1
60.9
65.4-44.2
Tray
3.5
29.3
60.3
53.6
67.1-51.6
Mean overall
overall survival
survival of
of spat
spat was
was 45%.
45%.
Sur­
Sur-
vival of tho August brood was
31%; October brood
was 44%;
44%; Septemer
September brood 31%;
brood 60%.
60%.
59%; January brood
Oyster spat survived better when planted during
than September,
Septemer, December,
December, and
and January
January (Table
(Tab Ie 8).
8).
the months under study than
Table 8.
8. Winter Survival of Laboratory-Reared Pacific Oyster
Spat Planted at
at Different Ages
Ages and Times
Times in Yaquina
Bay (Sampled April 1971)
1971)
Date Planted
Age of Seed
(Days)
(Days)
Survival
(t)
(%)
9-30-70 12
54
19.0
13.0
11-4-70 29
47
89
89
55.3
59.0
70.7
12-4-70 59
77
77
119
50.0
91
109
151
46.5
17.9
32.5
35
60.1
85.0
57.1
65.8
1-5-70
2-11-71
128
128
146
188
2.5
37.2
12.
12.
and Conclusions
Conclusions
Discussion and
Field Studies
Imported vs.
vs. Laboratory-Reared
LaboratOry-Reared Spat.
Because it
it is
is more
more practical
practical
Because
to measure
measure shell
shell size
size than
than meat
meat volume,
volume, and
and since
since shucking
shucking of
of oysters
oysters
precludes further measurement,
measurement, we
we wanted to determine
determine if shell
shell length
length
and width measurements accurately
accurately reflect
reflect oyster
oyster size.
size.
and
Mean shell
shell
Mean
length
a fairly accurate
accurate indication
indication of
of Pacific
Pacific oyster
oyster
length times
times width
width gave a
size in meat volume
(Figure 1);
volume (Figure
1); however,
however, this
this relationship
relationship was
was not
not
apparent with
with Kumainoto
Kumamoto oysters
(Figure 2).
2).
oysters (Figure
Length-width measurements
did not indicate meat volume for
for this
this species.
species.
ICumnamoto
oysters are
are
Kumamoto oysters
quite variable in
in shell
shell depth
depth (thickness),
(thickness), depending
depending on
on physical
physical conditions,
conditions,
such as
crowding during
during growth.
growth.
as the degree of crowding
Less crowded conditions
in the tray containing
containing imported
imported Icumamoto
Kumamoto oysters
resulted in
in
oysters probably
probably resulted
deeper oysters, hence the
the greater
greater volume
volume to
to length-width
length-width ratio.
ratio.
Thickness
is
is impossible
impossible to measure
measure while
while oysters
oysters are
are clustered or attached to
to cultch
cuitch
material •
material.
8,
.p
tlO
~.
...J 7,000
6,500
6,
6,000.~____~:-__~~__-.~____~~__-,~__~
20
Meat Volume
Figure
Figere 1.
I.
Mean
Mean Shell
Shell Size (Length
(Length Times
Times Width)
Width) vs.
vs. Meat
Volume (Shucked
(Shucked Count
COlDlt Per
Per Quart)
of Four
Four Groups
Groups
Volume
Quart) of
of Pacific
Pacific Oysters
Oysters
of
13.
13. 2,700
2,700
" "
"­
...
2,600
'1$'
~ 2,500
5::
-1"1
2,400
~
4.)
+J
~
I­
2,300
2,300
-
><
2,200
>
2,200
-
"0
-1"1
3:
tl
2,100 ~
~° 2,100
Q)
4)
...:I
2,000
...
""
" "­ "­
"­N
•
""
•
1,900
I
80
•
82
84
I
I
86
88
Meat Volwne
Volume
"­
" "­
"" N
1
90
"
1
92
Figure 22. Mean Shell Size
Size (Length
(Length Times
Times Width)
Width) vs.
vs. Neat
Meat
Volume (Shucked
(Shucked Count
Count Per
Per Pint)
Pint) of
of Three
Three Groups
Groups
Volume
of Kumamoto Oysters
Tray Culture at Different Depths.
Depths.
Poor shell growth in the
the stationstation­
ary intertidal tray was largely
largely due
due to
to the
the high
high tidal
tidal level
level of
of the
the tray.
tray.
ary
In suspended trays
trays growth
growth was
was equal
equal at all
all depths
depths after 19
19 months,
months, but
but
growth appears
(13
growth
appears much
much better
better near
near the
the surface on suspended strings
strings (13
after planting) being
being used
used in
in another
another study.
study.
months after
years of very
In years
low winter salinities, growth appears
appears to
to be slightly
slightly better
better in
in deep
deep
low
water levels where salinities
salinities are
are highest;
highest; in
in years
years of
of less
less severe
severe salinities,
salinities,
growth is better near
near the
the water's surface
surface where
where food
food production
production is
is greatest.
greatest.
String vs.
vs. Tray
Tray Culture.
Cuiture.
Oysters on rack strings
strings are
are the
the smallest,
smallest,
probably due to their
their tidal exposure.
Heavy fouling by mussels
mussels on the boom log strings probably retarded
oyster growth.
Many oyster
oys ter clusters
clusters were
were completely
comp lete ly covered
covered with
with mussels.
musse Is.
Growth was also impaired by the
the large
large number
number of
of spat
spat per
per cultch
cultch. shell.
shell.
Crowded conditions
conditions resulted in
in selfculling,
selfculling, the
the loose
loose oysters
oysters being
being
14. 14.
held in
in place
place by
by bysal
bysal threads
threads of
ofniissels.
llIlSsels.
We
recommend that
that cultch
cultch
We recommend
that has
has no more
more than
than 20
20 spat
spat per
per she
shell
be used
used for
for string
string culture
culture
that
11 be
(preferably
(preferab ly 10-15).
10-15).
Thinning could
could be done
done but this
this would require
require concon­
siderable time,
time, labor,
labor, and aa place
place to put
put the
the culled oysters
oysters until
until they
they
reach a marketable size.
We also
also recommend
recommend that
that spat
spat on
on strings
strings be
We
planted after
after the
the peak of the
the spring set of DRJSsel
larvae (about
(about April
mussel larvae
April 1
in Yaquina
Yaquina Bay).
Bay).
Winter
Winter Spat Survival.
Survival.
The mean
mean survival
survival of
of 45%
45% is
is excellent;
excellent; however,
hCMever,
some of the
the spat were
were much
much larger when planted
planted than is
is imported seed at
planting.
Because of
of the
the somewhat mysterious
mysterious mortality
mortali ty of
of the
the September­
Because
September-
planted
planted spat,
spat,
more information
information should
should be obtained
obtained in
in the
the future
future during
during
more
this time period.
larvae in the OSU hatchery
Oyster larvae
hatcheiy have also experienced
high mortalities during
during September.
September.
Vitality of
of spat set
set in
in September
September may
may
also be
be low since
since this
this brood
brood reflected
reflected the
the lowest survival
survival of the
the four
four
broods used
used in
in this
this study.
study.
ABALONE STUDIES
Methods
(Haliotis r'Ufescens)
Adult red abalone (llalioio
rufeacene) were obtained from the coastal
of southern
southem Oregon near Brookings
Brookings and
and from
from Whale Cove
Cove aa short disdis­
waters of
of Newport.
Newport.
tance north of
These adults were
were used
used for
for spawning
spawning stock.
stock.
The adults
adults were
were stimulated
stimulated to
to spawn
spawn by
by temperature
temperature fluctuation.
fluctuation.
The water temperature was
C to 19-20 C
C in a period of
was increased from 15 C
6 hours.
hours.
After it reached 19-20 C, it was allowed
allowed to cool.
This procedure
to be repeated several times before the abalone
abalone would spawn.
had to
After
spawning,
spawning, the fertilized eggs
eggs were
were siphoned out of the spawning tray
through aa filter
filter and
and placed
placed in
in an
an incubation
incubation tray.
tray.
After 24 hours the
IS.
15. reached and
and the
the abalone
abalone trochophores
trochophores began
began swimming.
swimming.
trochophore stage was reached
The trochophores were siphoned out of the incubation trays
trays and placed in
in
fresh sea
sea water.
water.
clean trays with fresh
Results
The spawned eggs of the abalone obtained from southern O):egon
Oregon were
were
and the
the resultant
resultant trochophores
trochophores survived
survived aa week.
week.
successfully fertilized and
abalone trochophores
The abalone
trochophores became entangled in mucus
mucus strings
strings,
clumped
l
and could
could not
not set.
set.
together, and
from Whale Cove.
A second group of adult
adult abalone were obtained
A
Only the males could
could be induced
induced to
to spawn.
spawn.
More adults
collected from
from southern Oregon but they died
died while being transported
were collected
to the Newport Laboratory.
Laboratory.
Discussion
Discus
si on
Adult
laboratory but
but
Adult red abalone were successfully spawned in the laboratory
larvae became entangled in mucus.
mucus.
problems arose when the trochophore larvae
Before further
further spawnings
spawnings are
are attempted
attempted aa more
more extensive
extensive literature
literature survey
survey
Before
will be made concerning spawning techniques
techniques.
*
Contact will be made with
biologists who have successfUlly
abalone.
successfully spawned and reared juvenile abalone.
More consideration
consideration will be given
given to
to the
the conditions
conditions of
of shipment
shipment of adult
adult
red abalone to prevent mortalities such as have previously occurred.
occurred.
iJtteIeI1 :41 TOWARD OBJECtIVES
PROGRESS
The objectives of
of the
the Clam-Oyster-Abalofle
Clam-Oyster-AbaloI,e rearing'
at its
its
rearing project at
inception was to develop methods
methods of
of spawning and rearing all native
species of clams, native oyster
oyster and
and the
the exotic
exotic Pacific
Pacific oyster.
oyster.
The long
long
The
mass culturing
these
range goal of the project was to develop methods of mass
culturing these
animals
animals to supplement natural
natural reproduction and create new clam beds
beds where
where
adverse water currents prevent setting.
16.
16 Oyster culture
that we
we phased
phased out
Oyster
culture progressed
progressed to
to the
the point that
out this
this
portion of
of the
theprogram.
program.
Working
Workingcooperatively
cooperatively with
with Oregon
OregonState
State University,
techniques
techniques were
were developed
developedfor
forspawning
spawningand
andrearing
rearingoysters
oysters in
in mass
massculture.
culture.
We conducted
the
testingininFY
FY1971.
1911. Oregon
Oregon State
has
We
conducted
thelast
lastof
of our
our field testing
State has
built aa pilot
pilotoyster
oysterhatchery
hatchery to
todemonstrate
demonstrate the
of oyster
oyster
built
the practicality
practicality of
hatcheries to
to the industry.
hatcheries
industry. Our
on field
field culture
culturemethods
methods and
and
Our studies
studies on
survival show
show that
hatchery seed is
is as
asgood
good as
as imported
imported seed and
and off­
spat survival
that hatchery
offbottom culture
increase survival and
and growth
growth rate
bottom
culture will
will increase
rate of oysters.
We have
and
reared
native clams
clams to
tosome
some degree
degree
We
havespawned
spawned
and
rearedallallof
of the
the native
The
The most
successful
gaper, and
and the native
native and
and
successful have
have been
beenthe
thebutter,
butter, gaper,
Manila
Manilalittlenecks.
littlenecks.
Razor clams
need considerable work
work before
Razor
clams and
and cockles
cackles need
we can
techniques to be
be of
ofvalue
valueand
andmore
more refinement
refinement is
is needed
needed
we
can consider
consider our
our techniques
in techniques
techniques for butter
butterand
and gaper
gaper clams.
clams.
While
broaden the
Whileeffort
effort to broaden
time period
which gaper
continued in
time
period over which
gaper clam
clam larvae
larvae can
can be
be obtained
obtained continued
FY
PY1911,
1971,most
moststudy
studywas
wasput
putononlearning
learninghow
howtotosuccessfully
successfully transplant
transplant
the
young gaper,
ttleneck clams
cl ams to
ld.
the young
gaper,butter,
butter, and
andIilittleneck
to the
the fie
field.
Progress
Wenow
nowfee
feel
that
has been
been encouraging
la Ii
ttlenecks . We
1 that
has
encouragingwith
withnative
native and
andmani
manila
littlenecks.
we
species and
and can
inverte­
we can
canmass
massrear
rearthe
thelittleneck
littleneck species
can contribute
contribute to
to our inverte-
brate resource.
brate
resource.
This
tested during
during fiscal
fiscal1972.
1912.
This will
will be
be field
field tested
Techniques for
spawning and
abalone are being
being developed.
developed.
Techniques
for spawning
andrearing
rearing abalone
LITERATURE
LITERATURE CITED
Phibbs, F. D.
D. 1968. Laboratory
Laboratory hatching
coast
Phibbs,
hatchingand
andrearing
rearingof
of Pacific coast
clams
Commercial Fisheries
Research and
andDevelopment
Development
clams and
and oysters.
oysters. Commercial
Fisheries Research
Act. Progress
1961, to
to June
June 30,
30, 1968.
1968. Fish
FishComm.
Comm.
Progress Report,
Report, July
July 1, 1967,
of
Oregon.
of Oregon.
12
12 p.
Laboratoryhatching
hatchingand
andrearing
rearingof
of Pacific
Pacific coast
1969. Laboratory
coast
clams
Research and
andDevelopment
Development
CommercialFisheries
Fisheries Research
clams and
and oysters.
oysters. Commercial
Progress Report,
1968, to
toJune
June 30,
30, 1969.
1969. Fish
Comm.
Fish Comm.
Act. Progress
Report, July
July 1, 1968,
of Oregon.
Oregon. 15
15 p.
___________ 1910.
1970. Laboratory
coast
Laboratoryhatching
hatchingand
andrearing
rearingof
of Pacific
Pacific coast
clams and
Research and
andDevelopment
Development
CommercialFisheries
Fisheries Research
clams
and oysters.
oysters. Comercial
Act. Progress
Progress Report,
1969, to
toJune
June 30,
30, 1970.
1910.
Report, July
July 1, 1969,
of Oregon.
Oregon. 16
16 p.
Fish
FishComm.
Comm.