2y
CLAM-ABALONE
AND REAR
REARING
C LAM-ABALONE SPAWNING
SPAWNING AND
INC COr.IPLETION
COMPLET
ION REPORT
REPORT July 1,
1, 1970
1970 to
to June
June 30,
30, 1973
1973 July
Gerald Lukas
Lukas Gerald
Fish
Fish Commission of Oregon Commerce U.S.
U.S. Department of Commerce
National Oceanic and Atmospheric Administration National
National Marine
Marine Fish
Fisheries
National
cries Service Commercial Fisheries
Commercial
Fisheries Research
Research and
and Development
Devclopmnt Act Project
No. 1-60-R
16O-R Project No.
July 1973
TABLE OF CONTENTS No. Page No.
PART 1.
1.
PART
ANNUAL REPORT
REPORT JULY
JULY 11,
ANNUAL
1972TOTO
JUNE
1972
JUNE
30, 30,
1973. 1973 .............
11 Introduction
11 Clam Studies
Clam
Studies ......
11 Methods. ......
Methods
11 Clam
Spawning, Larval
Juvenile
Rearing
Larvaland
and
Juvenile
Rearing ..........
Clam Spawning,
Manila
Littleneck
Field Studies
Studies -- Manila
Littleneck
Clams.Clams ............
11 Results..............................
Results •
33 22 Clam
Larval
and and
Juvenile
Rearing
Clam Spalming,
Spawning,
Larval
Juvenile
Rearing ..........
Field
Studies
. . . . . .........................
Field
Studies
3
3
4
4
Clams Clams .................
Manila Littleneck
Manila
Littleneck
Native Littleneck
Clams Clams .................
Native
Littleneck
4
4
88 10 Butter
....................... 10
Butter ClamsClams
...
10 Discussion
and Conclusions.
Discussion
and Conclusions ..................... 10
Clam
Larval
and Juvenile
RearingRearing
.
10 Clam Spawning,
Spawning,
Larval
and Juvenile
.......... 10
10 Field Studies
Studies - Manila
Clams.Clams ............ 10
ManilaLittleneck
Littleneck
Abalone Studies.
14 Abalone
Studies ............................. 14
Methods . .
14 Methods
.............................. 14
14 Abalone
Spawning ....................... 14
Abalone Spawning
Whale
CoveCove
Abalone
14 Whale
Abalone ...................... 14
Results . . . .
Results..............................
14
14 Abalone Spawning
.
14 Abalone
Spawning
....................... 14
IVhale
CoveCove
Abalone
15 Whale
Abalone ...................... 15
Conclusions
. .
Conclusions............................
16
16 Abalone Spawning
16 Abalone
Spawning ........................ 16
\Vhale Cove
Abalone
16 Whale
Cove
Abalone ....................... 16
Literature Cited
Cited •............................
.
PART
PART 2:
2:
SUMMARY OF PROJECT
PROJECT ACCOMPLISl1V1ENTS
1, 1970
1970 TO JUNE 30,
30, 1973
1973
SUMMARY
ACCOMPLISHMENTS JULY 1,
Introduction
. .
Introduction
Oyster Studies
Studies
Oyster
.
.
17
17 .............................. 17
17 ..............................
Clam
Studies
.
Clam
Studies
16
16 17
17 .............................. 18
18 Red Abalone Studies
Studies............................
19
19 LIST OF TABLES Page
No.
Page No.
Table No.
No.
Table
11
2
2
Mean Shell
Shell Length
Length and
and Percentage
Percentage Survival
Survival of
of Manila
Hanila Littleneck
Littleneck
Mean
Clams,
and Nine
Nine Months
Months after
after Planting
Planting in
in Yaquina
Yaquina Estuary.
Estuary.
Clams, One and
.
55
.
Mean Shell Length of Manila Littleneck Clams,
Clams, Five and Twelve
Twelve
Riverbend, Yaquina
Honths after Planting in Test Plots near Rivorbend,
Months
Estuary . . . . .
...................•
Estuary..............................
3
3
6
Mean Shell
Shell Length
Length and
and Percentage
Percentage Survival
Survival of
of i,1anila
Littleneck
Mean
Manila Littleneck
Clams in
in Experimental
Experimental Plot
Plot near
near the
the Breakwater
Breakwater in
in Yaquina
Yaquina Estuary,
Estuary,
April
11, 11,
1973. 1973
.
..
. . . . . . . . . . . . . . . . . . . . •
April
...........................
4
7
7
Littleneck Clams
Mean Shell Length and Percentage Survival of Hanila
Ianila Littleneck
in Alsea
andand
TenTen
Months
after
Planting
. . ........
... .
in
Alsea Estuary,
Estuary,Three
Three
Months
after
Planting
8S
LIST OF FIGURES
FIGURES
Figure No.
No.
Figure
1
1
2
33
PageNo.
No.
!e
Placement of
of Plexiglass
Plexiglass Partitions
Partitions in
in Fiberglass
Fiberglass Rearing
Rearing Trays
Trays
Placement
(top
view)
(top
view).
. . . ..............................
. . . . . . .
. . . . . • . . . . . •
22
Growth
Littleneck Clams
Growth Curve of Native
Native Littleneck
Clams Planted in Artificial
Artificial
Substrate Plot,
Plot, Yaquina
Yaquina Estuary ...................
. .
.. .
9
9
.
. .
Growth Curve
Curve of
of Butter
Butter Clams
Clams Planted
Planted in
in Artificial
Growth
Artificial Substrate
Substrate Plot,
Plot,
Yaquina Estuary .
. . ... .. .
. . ...........................
. .. ..
. ...
YaquinaEstuary
11
CLAN-ABALONE SPAWNI
NC AND
INC CLAN-J\13J\LONE
SPANNING
A;'JD REAR
REARING
PART 1.
1.
PART
ANNUAL REPORT JULY 1,
I, 1972
1972 TO JUNE 30,
3D, 1973 Introduction Laboratory studies
studies of
of the
the :Ianila
littleneck clam
clCU-:l (Venerupis semic2ecu3sata)
semideaUBsata)
anila littleneck
Laboratory
continued during the 1972-73
1972-73 project year.
year.
Attempts were made to
to improve
improve the
the
conditioning
conditioning procedure
procedure for
for adult
adult spmmel's
spawners and
and to
to increase
increase grm"rtb
growth of
of juveniles
juveniles held
held
in
laboratory trays.
trays.
in laboratory
Field studies included the
the establishment
establishment of
of new
ne\" Manila
~4anila littleIi ttle­
neck
neck test
test plots
plots and
and aa survey
survey of estuarial
estuarial areas
areas \'lhich
which offer
offer aa potential
potential for
for future
future
;·Ianila clam
clam plants.
plants.
Manila
Experimental ;\lanila
Manila and
and native
native ClaJll
clam test
test plots
plots established
established
Experimental
during the project year and
and prior years were
were monitored.
monitored.
Adul
t red abalone (Haliotis
(HaZiotis l'ufesaens)
for spawning
spat"rning experiments
experiments were
rufescens) needed for
Adult
obtained from Whale
\%ale Cove)
Cove, the
tIle southern
southern Oregon
Oregon coast,
coast, and
and Fort
Fort Bragg,
Bragg, California.
California.
Juvenile red abalone, planted in
in Whale
Whale Cove
Cove in
in 1967,
1967, were
\vere sampled
sampled for
for growth.
growth.
Clam Studies
Studies
!lcthods
Methods
Larval arid
and Juvenile
Clam Spawning, Larval
Juvenile Rearing
Procedures for
for spawning and rearing {.ianila
Ii ttlenecks were similar to
to those
Manila littlenecks
used in previous years (Lukas,
(Lukas, 1972).
1972).
Now conditioning procedures
New
lrocedures were developed
to red.uce
amount of time
to spawn.
to
reduce the amount
time spent
spent inducing
inducing the
the adults
adults to
Each group of
;,Ianilu
adults (60
(60 per group)
for spawning
Manila adults
group) to
to be used
used for
spawning were
were sexed by withdrawing
withdrawing aa
individual clam's
clrul1! s gonad
gonad and
and examining
examining it
it under
under aa dissecting
dissecting micromicro­
sample from an individual
scope.
The clams
clams were placed in t\·10
trays by sex and lweconditioncd
two trays
preconditioned one to
to seven
days
trays maintained
15 C by moans
days with
with water
water temperature
temperature ill
in the
the trays
maintained at
at IS
means of aa \Vater
water
immersion heater
thermorc:;ulator.
heater controlled by a thermoregulator.
this period,
period, an
an additional
additional
After this
\vas placed in
in the
the conditioning
conditioning tray.
tray.
heating element was
This
clement, attached to
to aa
This clement,
time clock, heated
heated the
the water
water to
to 17
17 CC for
for six
six hours
hours daily
daily for
fortwo
two(lays.
days.
Following
this, the
19 C for
this,
the temperature
temperature \Vas
was increased to
to 19
for aa six-hour
six-hour daily
daily period
period for
for two
two
days
21 CC for aa six-hour
six-hour daily
daily period
period for
for two
t,vo days.
days.
days and finally to 21
c:mditioning procedure,
procedure, the
the clams
clams were
were then
then induced
induced to
to spawn.
spawn.
cnditioning
this
After this
-2­
It
distribution of
of circulating
circulating raw
rmV' sea
sea
It has
has not
not been possible to get uniform distribution
water through the shallow
5ha110\., 100
100 liter
liter fiberglass
fiberglass trays
trays (51
(51 xx 27
27 xx 6-inches
6-inches deep)
deep)
used for rearing :'·lanila
juveniles.
Manila juveniles.
Juveniles
Juvel1iles show variable growth
gr0\1th depending on
Nhere
arc situated within aa tray.
tray.
where they are
uneven growth,
growth, plexiglass
To eliminate
eliminate tills
this uneven
partitions were added to
to direct the
the water
water flow
flO\'/ throughout
throughout the
the tray
tray (Figure
(Figure 1).
1).
-
i
I
27'
I
~.
________
l-
---,>1
51!!
I
51'
-----------~
cfi~· IIn
In £10\.,
flow
I ~. -.----'"-~-.----4-8-1~=====:::::==---·1
48
.
~
! SJiH
ll_.------'-'o~~ _._-=~_~I) t
Figure 1.
1.
Outflow
Parti tions in Fiberglass
Fiberglass Rearing
r~earing Trays
Trays (top
(top view).
ViCI\').
Placement of Plexiglass
Plcxigla5s Partitionsin
1/8--inch thick
\dth non-toxic
non-toxic silicone
silicone
The 1/8-.inch
thick partitions
partitions \'iere
were attached
attached to
to the tray with
seal.
t·lanila juveniles
j uveni les held
held in
in trays,
trays, with
with and
and without
wi thout nartitions,
partitions, was
',vas
Growth of Manila
compared after a three-week
three-week period.
period.
Field Studies
Clams.
Studies -- Hanila
Manila Littleneck Clams.
established in
in two
tl.,O
Experimental plots were established
estuaries,
and Alsea.
Alsea.
estuaries, Yaquina and
ilanila juveniles
juveniles were planted
planted in
in two
two areas
areas in
in Yaquina
Yaquina Estuary.
Estuary.
Manila
on the
the west
west side
side of
of Sally's
Sally's Bend.
Bend.
plot was established on
2,500
(50 clams/sq.
clams/sq. ft.)
ft.) in
in October
October 1972.
1972.
2,500 juvenilos
juveniles (50
A
50-square foot
A SO-square
TIle plot was planted with
The
The juveniles
juveniles averaged 6.2
6.2 mm
from 4.0
4.0 to
to 10.5
10.S mm.
mm.
and ranged from
:·1anila
Manila juveniles were also planted seven rlilcs
miles upstream from the mouth
mouth of the
Yaquina Estuary
Estuary on
on tile
the north shore.
Yaquina
Three 36-square Loot
foot plots
plots were
wore established
approximately
approximately 200
200 yarJs
yarJs apart
apart with
with tidal
tidal height
height ranging
ranging from
from 3.2
3.2 to
to S.O-foet
5.0-feet above
above
1m.,er low
10\v water.
water.
mean lower
averaging 6.7
6.7 mm.
mm.
Each
~Janila juveniles
juveniles (50/sq.
(SO/sq. ft.)
ft.)
Each plot
plot received 1,800 Manila
-3­
Experimental plots were
\Vere established
established in
in two
two areas
areas in
in Alsea
Alsea Estua.ry
Estuary approximately
approximately
2 miles
the north
north shore.
shore.
miles upstream from the mouth and on the
One plot measured 55 xx 4040­
feet
10,000 Manila clams
clruns (50/sq.ft.)
(50/sq.ft.) averaging
averaging 5.6
5.6 mm.
mm ..
feet and
and tias
was pl::mted
planted IVith
with 10,000
from 0.4
0.4 to
to 4.4-feet
4.4-fcet above
above mean
rowan lower
10lver low
101... water.
water.
height ranged from
\'lere established 200
200 yards
yards upstream
upstream from
from the
the first
first plot.
plot.
were
measured 66 xx 6-feet.
6-fect.
Tidal
Four small
small plots
plots
Each of these
these plots
plots
They \verc
a line perpendicular to
to the shore line
line
were set up in a
located at 1.8,
1.8, 2.8,
2.8, 4.1,
4.1, and
and 5.1-feet
S.l-feet above
above mean
mean lower
lowcr low
10\'1 water,
water.
and located
Each plot
anilc clams
1,800 juvenile
juvenile :·Ianilc
cla.'i1s (50/sq.ft.)
(50/sq.ft.) which
which averaged
averaged 5.6
5.6 mm.
mm.
received 1,800
A gravel bar south of the breakwater in Yaquina Estuary was
selccted as
A
was selected
as aa site
for
a large number of juvenile
juvenilo Manilas.
~·!anilas.
for introduction of a
in this
this area
area
The test plot in
Nas
estuaries Illhich
was the only one 0:('
oi five
five plots
plots in five
five different
different estuaries
which showed
showed good
good survival
survival
when sampled in
in the spring
spring of
of 1972.
1972.
juvenile Manilas.
Hanilas.
A
foot area received 426,000
A 3,800 square foot
These clams
clams ranged from 3.0 to
to 13.7 mm and \l1ere
were planted at
at
from 97
97 to
to 156/sq.
l56/sq. ft.
ft.
densities ranging from
Results
Clam Spawning,
Spowning, Larval
Larval and
and Juvenile Rearing
Rearing
nC\\I conditioning procedure of temperature manipulation was
was successful
successful in
The new
shortening the
the time
time spent
spent on
on inducing
inducingadult
adultflanilas
?Janilas to
to spawn.
s!'alvl1.
shortening
N'ould
,.until three
three to
to five
five days
days of
of working
l'lorking with
with them.
them.
would not spawn .until
Previously
clams
Previously,~ clams
With the new
procedure,
almost always
inducements on the
the first
procedure, males
males would almost
always respond to spawning inducements
first
day following
folloNing conditioning and
and frequently
frequently one
onc or
or two
tlVO females
fem:::tles would
\'lould also
also spawn.
spa\m.
On
the second
eggs usually
usually would
would be
be obtained
obtained to
to satisfy
satisfy our
our needs.
needs.
the
second day,
day, enough
enouh eggs
tIl the procedure Nas
clans would
One problem .d
with
was that on certain occasions the clans
spmm in the conditioning
evening follotdng
first day of spatvning
spawn
conditioning tray
tray the
the evening
following the first
spawning
inducements.
Pl3.cing
(10 C)
C) overnig:lt
Placing the
the clams
clams in aa cold
cold \'later
water bath (10
overnight did
did not
not
prevent spawning.
spawning.
These clams ,."ould
out completely.
completely.
would spawn out
-4-4­
A situation developed in September and October 1972 in which
\\fhich the sea lIIater
A
water
laboratory apparently
apparently was
\'las toxic.
toxic.
coming
coming into
into the laboratory
The eggs obtained in
in September had
had
very poor survival and
and in
in October
October the
the adult
adult Manilas
Manilas did
did not
not spawn
spa\'ln at
at all,
all.
Toxic
bay \\fater
water has
has been observed seasonally at
at the
the pilot
pilot oyster hatchery operation at
at
University I s Marine
Zviarine Science
Science Center
Center from
from June
June through
through October.
October.
Oregon State Universityts
The
duration and frequency of
of occurance
occurancc of
of toxic
toxic water
water has
has not
not been
been consistent
consistent however,
however,
In 1971,
1971, the oyster hatchery was unable to
to produce
producc Pacific
Pacific oyster
oyster seed
seed from
from the
the last
last
\'leek of
of June
June through
through September
September 77 (Dennis
(Dcllnis Lund,
Lund, personal
personal communication).
communication).
week
Sand and
and
Sand
carbon
carbon filtration
filtration and
and treatment
treatment with
with chelating
chelating agents
agents have
have not
not been
been effective
effective in
in
detoxifying the
the water.
water.
detoxifying
It is
of plankton
plankton blooms
blooms may
may put
put
It
is suspected that the die-off of
toxic material into
into the
the water.
water.
Personnel
Personnel operating
operating the
the oyster
oyster hatchery
hatchery \vcre
were able
able to
to successfully
successfully spawn
spawn native
native
and European oysters
1971 showing that
that certain species
oysters during
during the swnmer
summer of 1971
species are
tolerant to
to this
this phenomena.
phenomena.
Juvenile Manila clams
clams averaging
averaging 2.7
test the effectiveness
2.7 mm were used to test
effectiveness of
aa shallOlv
in improving
improving growth.
growth.
shallow tray with partitions in
After three weeks, juveniles
juveniles
in
thout partitions
in the
the tray
tray \vi
without
partitions averaged
averaged 3.0
3.0 mm
mm IIIhile
while those
those in
in the
the tray
tray with
with parti­
partitions averaged 4.4
4.4 mm.
The trays
trays have to
the
to be well
well supported since the weight of the
lIIater causes
causes the
the bottom
bottom to
to sag
sag and
and pull
pull away
away from
from the
the partitions.
partitions.
water
Our trays
trays were
supported by four
four 2 by 4's
4' s on edge
edge directly
directly beneath
beneath each
each of
of the
the partitions.
partitions.
Field Studies
Manila Littleneck
~·fanila
Littleneck Clams.
Clams.
The 5 x 10-foot
IO-foot plot
the west side of
plot established on the
Sally's Bend in Yaquina Estuary was sampled
Sally's
sampled in
in April
April 1973,
1973.
shells were found.
found.
No
4o live
live Manilas
Manilas or
or empty
empty
The area
area showed
showed no
no signs
signs of
of being
being eroded
eroded or
or scoured.
scoured.
l\1e found
found
We
cockles, averaging 3.7 mm in rib length,
length, in the plot at a density of S/sq.
5/sq.
juvenile cockles,
ft.
ft.
The presence of these juveniles was an indication that the substrate of the
plot was
was stable.
stable.
plot
-5­
Three plots
plots in Yaquina Estuary established seven miles
miles upstream \.,ere
were sampled
tlvicc;
1972 and
and again
again in
in April
April 1973
1973 (Table
(Tab Ie 1).
1).
twice; once in September 1972
of the juveniles increased 7.8
7.8 to
to 9.7
9.7 mm
111m in
in nine
nine months.
months.
The mean lengths
lengths
clams after
Survival of clams
9", but
the
the first
first month
month in the
the plot
plot was
was over
over 50
50%,
but <lfter
after nine l:lOnths
months perccntage
percentage survival
survival
ranged from 12.8
12.8 to
to 34.4.
34.4.
1110
tidal height of plot C
C at its lower
lower boundary is
is
The tidal
estimated to be
JC 4.
4.3-fect
the upper
upper boundary
boundary is
is
3-feet above
above 1;10an
mean low{.:!r
lower low
low (Vater
water while the
5.
O-feet.
5.0-feet.
'l1lCre
a difference in survival
survival bet~'lccn
10\'1er areas
areas
There \Vas
was a
between the upper and lower
of this plot.
Clams in the upper section of the plot had a survival rate
ratc of 2.7%
2. 7~6
Clams
length of 13.5 lilm
the lower
lONer section had a survival rate
and an average length
mm while those in the
of 38,7%
38.7% and an average
;J.verage length
length of
of 15.1
15.1 mm.
mm.
Table 1.
1. Mean Shell Length and Percentage Survival of ;'ianila
Littleneck
?anila Littleneck
Clams, One and Nine
Nine jl!ont;ls
in Yaquina
Yaquina Estuary.
Estuary.
Clams,
onths after Planting in
Plot
5, 1972
September 5,
SeEtember
Mean Shell
Percentage
Percentaze
(mm)
Survival
Length (mm)
April 23,
23, 1973
Mean Shell
Perccntage
Percentage
inm)
Length (mm)
Survival
A
10.5
SS.O
55.0
16.4
34.4
B
B
9.8
83.0
83.3
14.5
14,5
12.8
C
C
-
15.0
21. 7
21.7
An experimental
experir.lcntal [.Iani
la clam plot 'vas
cstablisi1ed near Riverbend
Rivcrbend
Manila
was established
(approximately
from the mouth)
cffects of clam
5.5 miles
miles upstream fran
mouth) in Yaquina Estuary to test the effects
size and density on survival
survival (Lukas,
(Lukas, 1972).
1972).
September 1972 and Hay
llay 1973
1973 (Table
(Table 2).
2).
obtain a meaningful
moaningful figure
figure on
on survival.
survival.
ratc ranging
ranging from
from 00 to
to 2.2%.
2.2%.
survival rate
l'ii th shrimp
shrimp burrows.
burr01.vs.
with
This
plot l'las
t\'lice; in
This plot
was sampled twice;
in September was
l<laS too
too small to
to
The sample in
larger and
and indicated
indicated aa
The :';11),
ay sample was larger
1Io....ever,
\Vas extensively
cxtensively honeycombed
However, the plot was
T:lis large population of shrimp probably had an effect on the
This
survival
clams since their activity has
has made the substrate unstable.
survival of tho
the planted clams
unstable.
T\vo
Aanila shells
Two empty .lanila
shells Nere
were found
found widcll
which had
had the
the margins
margins broken
broken and
and chipped
chipped indicating
indicating
predation by
by crabs.
crabs.
predation
-6­
-6-
The lengths
lengths of
this area clams
of the
the live clams
clams recovered indicated that in this
clams
were ablu
growth.
able to
to achieve good growth.
Table
2. Mean
f..l ean Shell Length of l,janila
Littleneck Clams Five and 1'Iwlve
Manila Littleneck
Twelve
Table 2.
I.tonths after
after Planting
Planting in
in Test
Test Plots
Plots near
ncar PJ.verbend,
rriverbcnd, Yaquina
Months
Estuary.
;'·10
an Length
Mean
(mm)
When Planted (mm)
Group!'
Group!!
1972
6, 1972
September 6,
Se)2tember
:Mean
lean Shell
Length (mm)
mm)
23.3
r,!ay 4,
4, 1973
May
1,1ean
Mean Shell
Length (mm)
(mm)
31. 7
31.7
11
11.
0
11.0
22
66,5;)c
.
22.6
32.0
3-A
3.7
3.7
22.0
28.2
3-B
3.6
19.1
26.9
Y
1/ All
groups except 3-L
3-B were
Here 16
16 months old.
old.
All groups
old.
The 3-B group was 44 months
plots, the mean shell lengths
lengths of the four
four groups of
After 12 months
months in the plots,
clams \Vere
clams
were greatcr
greater than those of other clams
clams planted in experimental plots
plots in
Oregon estuaries.
estuaries.
These averages
averages are also slightly
sliZhtly greater than the average
lengths
lengths of
of ~iani1as
Manilas aftl;;lT
after 12
12 months
months in
in t:1C
the substrate
substrate at
at Hood
Hood Canal
Canal in
in Washington
Washington
(Nosho and Chew,
Chelv, 1972).
1972).
Groups
Groups 1,
1, 2,
2, and
and 3-A \Vere
were the
the same
same age
age but
but had
had different
different growth
growth rates
rates in the
the
laboratory.
rapid growth.
grotvth.
growth rate.
grotvth
rate.
After
clams did not continue to maintain
After 12 months,
months, the group of
of large clams
The group of small
(3--\) were able to maintain a nearly similar
small clams
clams (3-A)
Group 3-B,
3-8, 1 year younger than group 3-A,
3-A, Has
achieve, in the
was able to achieve,
laboratory, aa mean length in 4 months
laboratory,
nonths which
'."hich took
took group
group 3A,
3A, 16
achieve.
16 months to achieve.
I-Im.rever,
rates \Vere
comparable.
However, after
after one year in
in the plot,
plot, their grm'lth
growth rates
were comparable.
-7­
-7experhlental Manila plot near
ncar the breakwater
breaki-mter in lower
lower Yaquina Estuary \4aS
The experimental
was
sampled in
in April
April 1973.
1973.
plot was
l;taS established
established in
in September
September 1971.
1971.
This llot
Sampling in
r"lay 1972
1972 indicated an average survival
survival of 16.5% and aa raean
mm
May
mean shell length of 10.5 mm
(Lukas,
(Lukas, 1972).
~,!ean
Mean
Crable 3).
3).
of 6. Hi (Table
shell
length in April
shell length
April 1973 was
was 18.3 nun
mm ldth
with an average survival
survival
As
1972, growth
£:rowth and survival varied according
accordin::: to the
tho location
As in 1972,
thc clams in
in the
the 10
10 xx 40-foot
40-foot plot.
plot.
of the
Table 3.
3.
Sub-Plot
Hean
Length and
and Perc3ntago
Perc:.mtage Survival
Survival of
of :ianila
:kmila Littleneck
Mean Shell Length
Littleneck Clams
Clams in
in
Experimental
,loar the
the Breakwater
Brcabmtcr in
in Yaquina
Yaquina Estuary,
Estuary, April
April 11,
11, 1973.
1973.
Experimental Plot near
Tidal 1/
II
Height (ft)
(ft)
;',lcan
Mean Shell
(1:1',1)
Length
Lengt!l (mm)
Percentage
Survival
y
Percentage
Perccntage Survival 2/
Since :,lay,
1972
May, 1972
A
3.9-3.3
15.0
9.2
30.7
13
B
3.9-3.9
13.0
6.4
35.6
C
C
3.8-3.9
14.2
3.4
24.1
0
3.6-3.8
3.6-3.3
19.0
11.
6
11.6
55.8
E
3.1-3.6
22.1
6.4
72.7
F
F
2.8-3.1
23.7
6.4
72.7
G
G
2.2-2.8
27.0
3.2
42.1
H
H
1.7-2.2
21.8
0.5
0.5
66.7
66,7
18.3
6.1
Total Plot Average
Y1/
Height above mean
mea1i lower
10\.,or low
low water.
'2/
l:..1
Perc;cntagc survival
clams in each sub-plot
Percentage
survival calculations
calculations based on the number of clams
1972 (Lukas,
(Lukas> 1972)
1972).
in ;'la),
May 1972
Growth
the clams
clams
Growth continued
continued to
to be
be better in t;lC
the lower portion of the plot ,,,here
where the
are submerged a greater
greater portion
po~-tion of
of the
the time.
time.
TIlC
clams in
in the
the lower
1m-rer portion
portion of
of the
the
The clams
months compared 'lith
with those in the
plot also had better survival in the last 11 months
the
upper part of
of the
the plot.
plot.
- 8­
in .]une
June 1972
172 were
Estuary in
''Iere
The experimental plots
plots ro-established
re-established in Alsea Estuary
Clams
Clams
twice during
during the project
sal>lpled twice
proj ect year;
year; in
in September
September 1072
1072 and
and in
in May
i!ay 1973.
1973.
sampled
in
5 x
x 40-foot
40-foot plot
September, a survival of
of l0
10 90 nearly three
thr.ee months
lot showed,
showed, in September,
in the 5
Averago length
length of the
the clans
clams was
lias 10.5
10. 5 nm.
1}~m.
Average
after being planted.
planted.
was sampled
The plot \lIas
;·lay 1973
19'73 and
and only
only one
one live
live 17.6
17.6:ma
:;lla Manila
;,hIlila was
\'Jas found.
found.
in May
1110
four 66 xx 6-foot
6-foot plots
plots when
~'lhen sampled
sampled in
in September
Septemberindicated
indicatedthat
thattile
the clams
clams
The four
were growing well
i'lell in
in the
the lower
lower three
three plots
plots (Table
(Table 4).
4).
tidal height of
of the
the
The tidal
upper
uppor plot ",as
was too
too high to
to allow
allow the
tile clams
clams to
to achieve
ac~licvc good
good growth.
grOi'lth.
Subsequent
in flay
May revealed
grcN well.
\VeIl.
sampling in
revealed that
that the
the clauS
clams whiC:l
which did survive grew
However,
was poor.
poor.
survival was
Table 4.
4.
Table
(-lean Shell Length
Length and Percentage Survival of
of Manila
:'lal1ih~ Littlenecks
Mean
Littienecks in Alsea
Estuary.
r.fonths after
after Planting,
Planting.
Estuary, Three and Ten Months
,.,
Sub-Plot
i,lay 1,
1, 1973
May
:1oan Shell
Shell
:·Iean
Percentage
Length
Sm'vival
Length (mml
(mj_ Survival
September
SC12tcmber 8,
0, 1972
Percentage
f·lean
Mean Shell
SUl'viwal
Surviv1
Lct' (mm)
(rrunJ_
LlJn&~.
Tidal
Height (ft)!/
Height.
(£t)1I
-
7.4
7.4
24.0
-
00
11.1
11.l
11.3
-
0
2.8
13.3
40.6
19.7
2.4
2.4
1.0
1.8
13.2
10.0
19.4
19.4
0.8
11
5.4
5.4
22
4.1
33
4
4
~
1/
lm'ler
1/
Approximate height of upper boundary of plot above mean lower
lm~ water.
,~ater.
low
In
1970, juvenile
juvenile native
no.tive littleneck
li ttleneck clams,
cla:ms~
In September 1070,
Native Littleneck
Littleneck Clams.
Clams.
in a
(Venerupis vtominea),
(Venerupi
ctceninea),1verc
were planted
planted in
in Yaquina
Yaquina Estuary
Estuary in a plot containing various
substrates (Phibbs,
(Phibbs, 1960).
1969).
:).ssess
survival.
assess growth and survival.
This
This nlat
tlot \-las
was sampled during ilay
May of 1971 and 1972 to
1972, the entire
entire plot
plot had been sampled.
sampled.
By i,lay
Nay 1972,
Recovered clams were
Recoverod
Hero replanted.
replanted.
Tho
sruaple made in April 1973
1973 Has
The sample
was to determine
gro\,lth
Ie to
tIl handling
growth only
only as
as it
it \'las
was not
not possib
possible
to determine
determine mortality
mortality associated
associated wi
with
handling
and replanting.
3.nd
The native littionecks
littlcnecks samplethin
sample,L.in April 1973
1973 had an average shell
length
length of
of 37.4
37.4nun.
nml.
TIlesc
These clams \~el'e
were nearly 42 months old and had been in the plot
30 months
(Figure 2).
2).
30
months (Figure
-s­
-
so 30
L)
.-;
,.....,
~
20 'Vi
t::::
ro
<:>
~
10 !
66
12
12
18
18 30
30
24
;·Ionths
:$onths
36
36
I
,
I
1
48 42
-
9-30-70
930-70
5-12-71
5-1-n
5-1-72
4-12-73
Figure 2.
Figure
2. Growth Curve
Curve of
of Native
Native Littleneck
Littleneck Clams
Clams Planted
Planted in
in
Artificial
Substrate Plot,
Plot, Yaquina
Yaquina Bay.
Bay.
Artificial Substrate
-10­
-10-
Butter Clams.
Clams.
Butter
Juvenile butter clams
clams (Saxidomus
(Saxidomus giganteus)
giganteus) were planted in the
artificial
artificial substrate plot in December
December 1968
1968 (Phibbs,
(Phibbs, 1969).
1969).
When sampled in April
Mlen
1973, the clams
five years old
old and
and had
had been
been in
in the
the plot
plot 52
52 months,
months.
1973,
clams were nearly Live
The
length of
of these
these clams
clams was
was 60.1
60.1 nun
mm with
average shell length
with aa range
range from
from 54.4
54.4 to
to 67.5
67.5 mm
mm
(Figure 3).
3).
Discussion and Conclusions
Spawning, Larval and Juvenile Rearing
Clam Spawning,
Rearing
The development
development of
of the
the neN
new conditioning
conditioning procedure has
has saved
saved time
time in inducing
inducing the
the
adult
spawn.
adult 1.lanila
Manila littleneck clams to spawn.
IIm-Jever) the
the occasional
occasional spawning
spa\<lning of
of the
the clams
clams
However,
in the
the evening,
evening, after
after aa fruitless
fruitless day
day of
of spalming
spawning attempts,
attempts, indicates
indicates that
that the
the proper
proper
combination of spawning inducements has not
not been
been achieved.
achieved.
As
As yet no consistent
pattern of clam response to spawning stimuli
stimuli has
has been
been noted.
noted.
When the
the female
female clams
clams
When
do
do spawn
spawn in
in the
the conditioning
conditioning tray
tray overnight,
overnight, the
the survival
survival rate
rate of the
the salvaged
salvaged eggs
eggs
is
is very
very poor.
poor.
females apparently spawn
spa\m completeLy
completely on these occasions,
occasions, it
it
Since the females
is
riew group
group of
of adults.
adults.
is necessary to begin conditioning aa new
Toxic bay "Jater,
water, which
which apparently
apparently affects
affects the
the spawning of 1"lanila
Manila adults
adults and
and
Toxic
survival
survival of the
the larvae,was
larvae,was not
not mentioned
mentioned as
as aa problem during
during the
the spawning
spawning and
and rearing
rearing
of 55 native
native species
species by
by the
the previous
previous investigator
investigator working
working on
on this
this project.
project.
It
be
It may be
that
ty
that the
the t~lanila
Manila littleneck,
littleneck, not
not indigenous
indigenous to
to this
this area,
area, has
has not
not developed
developed an
an inununi
immunity
to
the toxicity.
toxicity.
to the
The spawning
spai.,rning of I'/anila
laboratory will have to be
ianila adults in the laboratory
scheduled
through October
October period.
period.
scheduled to
to occur outside of the June through
TIle addition of the partitions
partitions in the shallow fiberglass
fiberglass trays helped to increase
The
growth of
of Manila
;'1anila juveniles
juveniles exposed
exposed to
to raw
raw sea
sea water
l>later circulation.
circulation.
i-Ianila Littleneck
Littleneck Clams
Clams
Field Studies -- Manila
factors in establishing the Manila
~·1anila littleneck
Ii ttleneck in Oregon
One of the limiting factors
the lack
lack of
of suitable
suitable habitat.
habitat.
estuaries has been the
There are
are areas
areas which appear
appear to
to
70 -­
7°T
-r I
I
!
I
I
I
I
60
t­
/,,/i
I
/;/
I
.'/
I
t
i I
I
50
50
;/"" ,," 1 pm
;/'
I
t
Q)
~ 4O
40
c::
tI1
rC
4J
4.4
.,-l
~
'A
'£iJV
30
~
Q)
.....:.1
....
....
+
I
~/i
t
//
/
//
i-'
i-'
,
/
! ,/
\/
1/
tI
-'1
/
,/,l
t
,1/7
!
10
I
/
~
20
Vl 201
j0
-'
-
//'"
'/
(
.-.
­
-I
/
/1
//
~
4I Clams
Clams Planted
'.;.
/
/"
/'
•
•
I
•
I, '
_ _.2._.L-L....!..._..
_!__
L.}____
_'_. __'j __
I _.:.
_
L ...L
I
6
6
12
12
18
18
24
24
36
30
30
I
•..__'_...
L
LJJ_Lw_L
•
_1_'1._.
42
42
48
48
L....LJ
LLJ
54
60
60
'l-fonths
Months
I
12-15-68 6-8-69
6-8-69 12-26-69
12-9-70
4-20-72
4-12-73
3-25-70 Date Sampled 3.
Figure 3.
Grol'Jth
in Artificial Substra~
Bay.
Growth Curve of Butter Clams Planted in
Substra Plot,
Plot, Ye,c;uina
Yquina Bay.
-12­
have suitable substrate,
mortalities in test plots in these areas
areas approach
approach or
or are
are
substrate, but mortalities
100
100 percent.
percent.
Examples of this
this were seen at
Riverbend in Yaquina
Examples
at Sally's
Sally's Bend and Riverbend
E$tuary
Alsea Estuary.
Estuary.
Estuary and in the test p~ot
p'ot on the Alsea
have been
been related
related to
to weather
weather conditions
conditions during
during the
the winter.
winter.
Mortalities may have
In
December
December 1972,
1972, there
there \'ias
was aa period
period of
of 77 days
days of
of subfreezing
subfreezing temperature
temperature ~vhich
which may
may have
have
some effect
effect on
on the
the survival
survival of
of juvenile
juvenile Manilas
Mani.las high
high on
on the
the tide
tide flat.
flat.
had some
Other than
this
this period
period in December,
December, the
the winter
winter of
of 1972-73 \vas
was relatively
relatively mild
mild with
with less
less than
than
nonnal
normal rainfall
rainfall and
and there
there were
were no
no periods
periods of
of prolonged
prolonged freshets
freshets which
which could
could have
have
been a factor in
in clam
clam mortality.
Manilas in the test plots which did
The juvenile Manilas
survive have shown average growth
grmvth indicating
indicating an
an adequate
adequate amount
amount of
of food
food available.
available.
~Ianila
Manila
clams
clams in
in the
the three
three plots
plots in upper
upper Yaquina Estuary varied
varied in survival
survival
l'lhich may have resulted from differences of the substrate and/or burrowing
burrmdng shrimp
which
activi ty.
activity.
TIle
clams in these plots
less than average growth probably
The ~Ianila
Manila clams
plots achieved less
the plots were
lvore at
at too
too high
high aa tidal
tidal level.
level.
because the
The clams could not be planted belolv
below
3.0-feet above
above mean
mean 10\"er
lower low
low water
water in
in this
this area
area because
because of
of the
the occurrance
occurrance of
of aa
3.0-feet
thick layer
layor of
of silt.
silt.
C indicates that in
The poor survival of the clams in the upper portion of plot C
this
lower low
low
this area of
of the
the estuary
estuary aa tidal
tidal height
height approaching
approaching S.O-feet
5.0-feet above
above mean lower
water is the
the upper limit
limit for
for Manila
Manila planting.
planting.
The
The experimental
experimental size-density plots
plots near Riverbcnd
Riverbend were within aa tiJal
tidal range
range of
0.7 and
and 1.4-feet above mean lower
0.7
lower low
low water.
water.
growth even though
though survival
survival was
was poor.
poor.
The clams in these plots achieved good
One of the
the obj
ectives of this
this study l"as
objectives
was to
to
determine if the faster
faster growing
grO\ving laboratory-reared clams could maintain a faster
growth rate in
in the
the field.
field.
size was
\'las small,
small, the
the data
data indicates
indicates
Even though our sample size
that
to the
that the
the small
small clams
clams lV'ere
were able
able to
to achieve
achieve aa growth
growth rate comparable
comparable to
the medium
medium and
and
large size clams (Groups
(Groups 1I and
and 2).
2).
It appears
in growth
growth of
of clams
clams
It
appears that the differences in
of our
our labroatory
labroatory technique.
technique.
are the result of
-13­
survival of the ilianilas
The activity of burrowing shrimp and the poor survival
Manilas are
probably related.
related.
probably
Tests need to be made to compare clam
cla~ survival
survival in an area in
llThich the
the shrimp
shrimp have
have been
been eradicated.
eradicated.
which
1110
The grollTth
growth of the
the nanila
Manila juveniles
juveniles in the
the experimental
experimental plot
plot on the
the breakwater
breakwater
in Yaquina Estuary
Estuary has
has been
been less
loss than
than the
the grm'l'th
growth of
of l\lanilas
Manilas in other
other plots
plots in
in the
the
estuary.
estuary.
The tidal
tidal height
height of the plot
plot and location in the estuary may have
have an
influence
on growth.
growth.
influence on
The clams in
in the upper portion of the plot have a significantly
smaller mean shell
shell length
length than
than clams
clams from
from lower
lower portions
portions of
of the
the plot.
plot.
The
TIle estuary
area near
less
near the
the mouth,
mouth, being
being cooler
cooler than the
the upper
upper estuary,
estuary, probably produces
produces less
phytoplankton.
The higher survival
survival of the
last sample in
the clams
clams in lower subplots
suhplots since the last
May 1972
1972 might
less exposure during
might be related to
to less
during the period
period of subfreezing
subfreezing weather
weather
mentioned previously.
previously.
mentioned
TIle
the plots in
in Alsea
Alsea Estuary
Estuary was
was aa disappointment.
disappointment.
The failure of the
If
clams
If the
the clams
had survived well,
for several
juveniles to
well, this
this area had
had aa potential
potential for
several million juveniles
to be
planted yearly.
yearly.
The growth of the survivors in
in the
the plots
plots was
was average.
average.
Estuaries Oll
coast were surveyed to locate
locate sites
sites where
Estuaries
on the southern Oregon coast
Hanila littleneck
Ii ttleneck test
test plots
plots could
could be
be established.
established.
Manila
Of the four estuaries
estuaries examined,
examined,
hnpqua, Coos,
Coos, and
and Coquille,
Coquille, only
only Coos
Coos had
had aa sizeable area
which included
included Siuslaw,
Siuslaw, Umpqua,
which appeared to be suitable for
for the
the establishment
establishment of
of Manila
Manila littlenecks.
li ttlenecks.
Estuary
sui table.
Estuary offered one area which may be suitable.
Coquille
Coquille
Test plots
established in
in
plots will be established
these two
two estuaries
estuaries during
during the
the next
next project
project year.
year.
these
We received a request from Oregon Aqua Foods,
Foods, a newly
nellTly formed company involved in
Ve
mariculture,
10,000 juvenile
juvenile Manila
Manila littlenecks.
littlenecks.
mariculture, for 10,000
\vi
thin their
their mariculture system.
system.
within
to roar
rear these
these juveniles
juveniles
They plan to
We have agreed to supply these clams
clams on the concon­
dition that
that all
all data on the ha.ndling
handling facilities
facilities and the clams growth and survival will
will
be available for
for our
our use.
use.
-14­
\'Ie
blanila littleneck
littleneck offers
offers aa good
good potential
potential for
for use
use in
in marlmari­
We believe that the Manila
culture because of
larvae
culture
of the
the relative
relative case
ease of
of spawning
spawning the
the adults
adults and
and rearing
rearing the
the larvae
and juveniles.
01'egon Aqua Foods
Foods will
the
The planned use of these juveniles by Oregon
will be the
first
littlenecks for
for commercial
commercial purposes
purposes in
in Oregon.
Oregon.
first evaluation of rearing Manila littlenecks
Abalone Studies
Methods
Abalone Spawning
for spawning in
Adult red abalone were obtained from three sources to be used for
the laboratory.
laboratory.
Animals
subtidal areas
areas in Whale
~~alc Cove,
Animals were collected from subtidal
Cove, on the
southern Oregon coast near
ncar Brookings,
Brookings, and
and near
ncar Fort
Fort Bragg,
Bragg, California.
California.
weeks were spent
spent trying
trying to
to induce
induce these
these animals
animals to
to spawn.
spawn.
singularly or in
in combination.
combination.
Several
Several
Three methods were used
\vere desication
desication, holding the
the abalone
abalone dry
dry
These methods were
for 1½
lJ.z hours;
hours; thermal
thermal stimulation,
stimulation, increasing
increasing the
the \V'ater
temperatures from
for
water temperatures
from ambient
ambient
(10-13
22C; and
and chemical
chemical stimulation,
stimulation,
(10-13 C)
C) to
to 15-18
15-18 C with
with an occasional maximum to 22C;
potassium chloride
chloride at
at aa rate
rate of
of 1-2
1-2 grains/liter
grams/liter for periods of
of ½J.z - 11 hour.
using potassium
hour.
Whale
i~lale Cove Abalone
ar{)as of Whale
\\~ale Cove were searched for
for red abalone
The intertidal and subtidal areas
planted as juveniles
juveniles in
in May and
and June
June 1967.
1967.
These animals 'vere
were purchased from a
commercial
commercial hatchery
hatchery in
in California
California and
and planted
planted by
by members
members of
of Shellfish
Shellfish Investigation
Investigation
staff to
survival of juvenile abalone on the central Oregon
to evaluate the growth and survival
coast.
This project was taken
taken over
over by
by the
the Clam-Abalone
Clam-Abalone project
project in
in 1970.
1970.
The juveniles
juveniles
recovered in June 1972
1972 were
\vore measured, tagged,
tagged, and
and replaced.
replaced.
Results
Abalone Spawning
Spa\vning
1/1e Whale
to spawning
spawning inducements.
inducements.
thO
Whale Cove abalone did not respond to
A few
few hundred
hundred
A
thousand eggs
eggs were
were obtained
obtained from
from sporadic
sporadic spawning,
spawning, but they failed to develop even
even
though sperm was present and fertilization
fertilization should
should have
have occurred.
occurred.
-15­
The abalone obtained
obtained from
from Fort
Fort Bragg
Bragg had
had full
full gonads.
gonads.
The males released
released small
small
amounts
amounts of
of sperm
sperm during
during the
the daytime
daytime in
in response
response to
to the
the spawning
spawning inducements
inducements and
and also
also
during
inducements.
during the night without inducements.
released large
large quantities
quantities of
of sperm.
sperm.
There were
were several occasions
occasions when
when the
the abalone
abalone
Neither the
the presence
presence of
of sperm
sperm nor
nor the
the mechanical
mechanical
Neither
or chemical
chemical inducements
inducements caused
caused the
the females
females to
to spawn
spawn freely.
freely.
or
was changed
changed in
in the
the morning
morning of
of each
each day.
day.
was
The \mter
in the
the tanks
tanks
water in
A
A few hundred trochophore larvae
larvae were
obtained \Vi
th each
each change
change of
of water
\'Jater for
for aa period
period of
of about
about three
three weeks.
weeks.
with
The larvae
larvae
The
\~ere held
held in
in two-liter
two-liter beakers
beakers in
in aa constant
constant temperature
temperature bath
bath kept
kept at
at 14
14 C.
C.
were
The
The
survival
larvae was very
very poor
poor although
although some
some did
did survive
survive for
for nearly
nearly two
two weeks.
weeks.
survival of these larvae
did not settle
settle on
on glass
in the
the
They did
glass slides
slides coated with diatoms
diatoms which were placed in
beakers.
beakers.
Only one
one of
of the
the female abalone
abalone obtained
obtained from
from the
the southern
southern Oregon
Oregon coast
coast responded
Only
to spawning
spawning attempts.
attempts.
to
14 C.
14
C.
n~o
Two
The female
female was held in
in aa 90-liter
90-liter tank
tank at
at aa temperature
temperature of
of
The
liters of
of concentrated
concentrated sperm
sperm was
was added
added to
to the
the tank.
tank.
liters
she spawned
spawned several
several million
million eggs.
eggs.
she
remove excess sperm.
sperm.
glass
carboys.
glass carboys.
inree
later
Three hours later
The eggs
and carefully
carefully washed to
to
eggs were removed and
The eggs
eggs \'lere
were divided into four
four groups and placed in 16-liter
Three carboys
15 C
carboys were
were placed in a water
water bath at 15
C and
and the fourth
fourth was
was
water bath at 11
placed in a "later
11 C.
C.
nventy hours
hours after
after spawning
spawning the
the eggs
eggs were
were examined.
examined.
Twenty
Development had reached
larvae \vere
reached the trochophore
trochophore stage but
but the larvae
were encapsuled
encapsulod in the
the
egg case.
casc.
The trochophores
trochophores were
were active
active and
and were
\<lere rotating
rotating within
·within the
the egg.
egg.
nlfO
days
Two days
after
after spawning
spawning a fe\~
few of the
the trochcphores
trochophores had
had broken through the egg
egg membrane but
but
they
larvae obtained
they did
did not
not appear
appear to
to be
be developing
developing normally compared with the
the larvae
from the
the California
California abalone.
abalone.
By
By tIle
the third
third day,
day, it
it was
was apparent
apparent that
that none
none of
of the
the
larvae were going to
to develop
develop normally
normally and
and they
they were
were discarded.
discarded.
larvae
Mlale
Whale Cove Abalone
Fifty-three red
red abalone
abalone \vere
were COllected,
collectcd, measured,
measured, tagged,
tagged, and replaced in the
intertidal area in
in Whale
Whale Cove.
Cove.
No animals
animals were found
found in
in the
the subtidal
subtidal area ncar
No
near the
-16­
The average length of the recovered abalone was
mm wi
with
range of
TIle
was 105 1;!f.1
tIl aa range
planting
site.
planting site.
69-170
mID.
69-170 mm.
TIlese
fron about
about 5-20
5-20 mm
rom when
when planted.
planted.
These animals ranged from
On ten of the
abalone, it was
was possible to measure size at time of planting because of the
dIe difference
abalone,
difference
in shell
shell color.
color.
The average increase in shell length
length of these ten animals
animals \'Jas
78 mm
was 78
\I!ith aa range
range of
of 61-95
61-95nim.
mm.
with
Conclusions
Abalone Spawning
Spawnins
The abnormal
large number of eggs
eggs obtained from
from one
abnormal development
development of the large
one female
female \.;as
was
aa dissappointment.
No cause for
for this could be determined.
determillcu.
TIle eggs
eggs were
l'lere handled in
in aa
The
manner similar to that
that used for bivalve eggs which
Nhich has been successful.
successful.
to spawn
spa\·m may be
be related
related to
to any
any of
of several
several causes:
causes:
of the other females to
TIle
The reluctance
the females
were not
condition, the
the spa~ming
not in condition,
spawning stimuli
stimuli Nore
were not
not auequate,
adequate, or water chemistry Nas
was
females would
would not
not respond.
respond.
such that the females
At present,
present, there is
is no \.;ay
way of knowing
knowing if any
factors were
\Vere related to
to the
the spawning
spawning failure
failure of
of the
the females.
females.
of these factors
Whale Cove Abalone
The growth attained in 5 years
years by the planted juvenile red abalone cannot be
lack of data available on
on the
the growth
grov;th of
of young
young abalone.
abalone.
evaluated because of the lack
Based
Based
observations by California abalone
on observations
abalone biologists,
biologists, the
the growth could be considered
average (Dick
(Dick Burge,
Burgo 1 personal
personal communication).
The
The recovery
recovery of
of only
only 63
63 abalone,
abalone, indi­
mdi-
of 1%,
1 96, also
also cannot be evaluated.
evaluated.
cating a survival of
It is
these
It
is encouraging that some of these
diJ survive
survive and
and are
are g:
grOl·ling
average rate.
rate.
abalone did
rowing at an average
Literature Cited
Lukas, C.
G.
1972.
Clam-abalone spawning and
and rearing.
rearing.
Commercial
Commercial Fisheries Research and
Development Act.
Act. July 1,
1, 1971
1971 to
to June
June 30,
30, l)72.
1072. Fish
Fish Comm.
Comm. of
of Ore.
Ore. Proc.
Proc. Rept.
Rept. 16
16 p..
p.
Nosho, T.Y.
T.Y. and
and K.K.
K.K. Chew,
Chc\.,.
Nosho,
japonica
1972.
TIle
and growth
grOl'7th of
of the
the Manila
r,janila Clam,
Clam, Venel'upis
Venerupis
The setting and
(Deshayes),
Pioc.
~Sheilfish Assm
!SO"S8;
(Deshayes), in
inHood
HoodCanal,
Canal,Washington.
Washington.
Poc.Na:t-~
NatShellfish
Assn. 62
62:50S8
Phibbs,
1969. Laboratory hatching and
and rearing
rearing of
of Pacific
Pacific coast
coast clams
clams and
and oysters.
oysters.
Phibbs, F.D.
F.D. 1969.
Commercial
and Development
Development Act.
Act. July
July 1,
1, 1968
1968 to
to June
June 30,
30, 1969.
1969.
Commercial Fisheries Research and
Fish Comm.
Proc. Rept.
Rept. 15
15 p.
p.
Comm. of Ore.
Ore. Proc.
-17-17­
PART
2:
PART 2:
SUHMARY OF PROJECT
PROJECT ACCOr.1PLISHHE~'TS
1, 1970
1970 TO JUNE 30,
30, 1973
1973 SUMMARY
ACCOMPLISHMENTS JULY 1,
Introduction
Introduction
The objectives
objectives of
of this
this project
project arc
are to
to develop
develop techniques
techniques for
for spawning
spawning and
and
rearing commercially
commercially and
and recreationally
recrcationally important
important bivalves
bivalves and
and abalone.
abalone.
rearing
TIle long
long
The
range goal is to develop Llethods
species to supplement natural
methods to mass
mass culture these species
natural
production, to
te establish
establish new areas
areas of
of production,
and to
to determine the
the feasibility
production,
production, and
feasibility
of aa hatchery
hatchery operation
operation for
for commercial
commercial purposes.
purposes.
of
Oyster Studies
Studies
During
1971, the
tho oyster
oyster portion
portion of
of the
the project
project was
was phased
phased out.
out.
During fiscal
fiscal year 1971,
The
The
techniques for
for spawning and rearing
techniques
roaring oysters
oysters in mass
mass culture had progressed to the
the
point that
that Oregon State University built a pilot oyster hatchery at the :"Iarine
Marine
this type of operation to the
Science Center to demonstrate
demonstrate the practicality of this
oyster industry.
industry.
Field studies
studies concluded during
during the year compared the growth of
laboratory-reared
laboratory-reared and
and imported
imported spat
spat in
in the
the field,
field, evaluated
evaluated tray
tray culture
culture at
at
different depths,
depths, and
and compared
compared string
string and
and tray
tray culture.
culture.
Results showed
showed that
that after
after
Results
19 months,
imported Pacific
Pacific oysters
oysters averaged
averaged the
the same
same in
in both
both shell
shell
months, hatchery and imported
size and meat volume.
Laboratory-reared Kumamoto
Kumamoto oysters produced
produced 9%
9% less
less meat
Laboratory-reared
than imported
imported Kumaznoto
Kumamoto oysters
20 months
months in
in the
the field.
field.
than
oysters after
after 20
A group of juvenile
juvenile Pacific oysters
oyst~rs were divided into
into 4 lots
lots and cultured
cultured in
A
suspended trays
trays at
at depths
depths of
of 3,
3, 6,
6, 9,
9, and
and 12-feet.
12-feet.
At the end
end of
of aa 19-month
19-month period,
period,
growth of these
these oysters
oysters was
was nearly
nearly the
the same
same at
at the
tho four
four depths
depths tested.
tested.
GrOl'lth of
of
Growth
Pacific
Pacific oysters
oysters in
in trays
trays was
was comparable
comparable to
to oysters
oysters cultured
cultured on strings
strings hung
hung from
from aa
boom
boom log.
log.
After 13
13 months,
on strings suspended
suspended on
on a fixed
fixed rack averaged
averaged
months, oysters
oysters on
10 mm less
less than aa comparable
comparable group
group of
of oysters
oysters in
in aa suspended
suspended tray.
tray.
-18­
- 18-
Clam Studies
During the three-year period,
period, the clam phase of the project was
was directed
developing spawning and rearing
rearing techniques
for mass
mass culture of the
the
primarily towards
towards developing
techniques for
Manila
littleneck clam.
clam.
Manila littleneck
Field studies
plots in several
several
studies involved establishing test plots
estuaries to
to evaluate suitability of selected sites
for further
estuaries
sites for
further introduction of
of
laboratory-reared Ianila
Manila clams.
ciams.
Mass culture
culture techniques
techniques for 1,lanila
clams were developed to
to the
the point where it
Manila clams
is
juveniles in
in the
the laboratory.
laboratory.
is possible
possible to
to produce large numbers of juveniles
We have been
techniques to achieve maximum
and will
will continue to refine spawning
spawning and rearing
rearing techniques
of juveniles
juveniles in
in the
the laboratory.
laboratory.
survival and growth of
One of our future objectives
objectives is
is
the feasibility
increasing growth and survival
to investigate the
feasibility of increasing
survival through selective
selective
breeding.
breeding.
Laboratory-reared
Laboratory-reared juvenile
juvenile :·1anila
Manila clams
clams were
were planted
planted in
in five
five estuaries
estuaries in
in
fiscal year
year 1972.
1972.
Only in
in Yaquina
Yaquina Estuary
Estuary have
have the
the test
test plots
plots been
been successful.
successful.
The
The
average growth
growth achieved
achieved by
by ~1anilas
Manilas in these
these plots
plots has
has been comparable to
to the growth
growth
of Jv'.t8.nilas
Manhlas in Hood Canal, Washington.
Survival was
was judged
judged to
to be
be adequate.
adequate.
During the
the fiscal
1973, we
During
fiscal year
year 1973,
we mass
mass planted 426,000 juvenile ~1anilas
Manilas in one
area of Yaquina Estuary to establish
establish aa population
population of
of Manila
;\1anila littlenecks.
Ii ttlenecks.
There are
still
l'le will
will establish
establish test
test plots.
plots.
still areas
areas in other estuaries where we
Other field
1971-73, involved the
the monitoring
field work,
work, during
during fiscal
fiscal years
years 1971-73,
monitoring of
growth and
littleneck clams
laboratory­
and survival
survival of butter
butter clams
clams and
and native
native littleneck
clams planted as
as laboratoryreared juveniles
juveniles in
in an
an artificial
artificial substrate
substrate test
test plot.
plot.
This plot,
established in
in
plot, established
1968,
gravel of
of different
different sizes
sizes placed
placed on
on aa silt-sand
silt-sand tidetide­
1968, had crushed and river-run gravel
flat
in Yaquina
Yaquina Bay.
Bay.
flat in
Results
littlenccks after
Results show that
that native littlonecks
after 19 months
months in the plot
plot
had survival
survival rates ranging up to 20% depending upon the gravel they were planted in.
in.
-19­
Maximwn
24 months in
in the
the test
test plots.
plots.
1aximurnsurvival
survivalof
ofbutter
butter clams
clams was
was 3.3%
3.3% after
after 24
While
we have no
comparisons to
to evaluate
the plot,
no comparisons
evaluate growth
growth of
of these two species
species in the
plot, it
it is
is
felt they are
achieving normal
normal grolVth
growth rates
rates based on the
appearances of growth
growth rings
rings
felt
are achieving
the appearances
on the
the shell.
shell.
on
The
this plot
that it
The success
success of this
plot indicates
indicates that
it is
is feasible
feasible to
to create
create new
new
clam
have aa high
high percentage
percentage of
of gravel.
gravel.
clan beds \vith
with dredge spoils which have
A
A pilot study
study
should be
be considered.
considered.
should
Red
Red Abalone Studies
Red abalone are found
founc.l in
in modest abundance
abundance on
on the
the southern
southern Oregon
Oregon coast.
coast.
It
It was
conceived
turing, we could spa\oJn
conceived that,
that, based on the
the success
success of bivalve cuI
culturing,
spawn and
and rear
rear
red abalone
the laboratory
laboratory and
the juveniles
abalone in the
and plant the
juveniles in selected
selected areas
areas along
along the
the
southern Oregon coast to
to supplement
supplement natural
natural production.
production.
We have not been very successful
successful in
in this
this endeavor.
endeavor.
inducing
to spawn
5pawn gave
gave marginal success.
success.
inducing red
red abalone to
for
The techniques used for
We induced spawning of
of male
abalone from each
each group
th, but
group of adults
adults \ve
we worked
worked \vi
with,
but female
female abalone
abalone have not
not
respondec.l
responded well
well to inducements
inducements 0r,
or, when spawning,
spawning, producec.l
produced non-viable eggs
eggs indicating
indicating
incomplete gonad development.
c.levelopment.
inducements.
females spawn readily to
Only on two occasions did females
One group of larvae
larvae developed,
developed, but survived
survivec.l only a week while the
other group never did
dic.l develop normally.
normally.
unsatisfactory.
been unsatisfactory.
in this
this phase of
of the
the project
project has
has
Progress in
Proper conditioning procedures need to be develop to allmv
allow
female abalone to achieve maximum
maximwn gonadal
gonadal development.
development.
this is
is accomplished,
accomplished,
After this
we feel confident
confident that
that we
we will
,vill be
be able
able to
to spawn
spawn the
the abalone
abalone using
using current
current techniques.
techniques.
We
to evaluate
We have
have not
not had
had enough experience
experience in handling
handling juvenile abalone
abalone to
evaluate our
our
techniques.
techniques.
Our guidelines
for this
this phase will follow
follmv those developed for bivalve
guidelines for
larvae
larvae and
and juveniles
juveniles plus
plus whatever
whatever information
information can
can be
be obtained
obtained from
from the
the literature
literature
and from persons involved
involved in
in abalone
abalone research.
research.