I C
CLAM-ABALONE
CLAM-ABALONE STOCK
STOCK SUPPLEM£NTATION
SUPPLEMENTATION FEASIBILITY
FEASIBILITY STUDY
STUDY ANNUAL REPORT
REPORT ANNUAL
July 1,
1. 1973
1973 to
to June
June 30,
30. 1974
1974 July
by
by
Gerald Lukas
Lukas
Gerald
Thomas F.
F. Gaumer
Gaumer
Thomas
Fish
of Oregon
Fish Commission
Comuission of
Oregon
U.S.
Department of
of Coimnerce
Commerce U.S. Department
National Oceanic
Oceanic and
and Atmospheric
Administration National
Atmospheric Administration
National Marine
Fisheries Service
National
Marine Fisheries
Service Commercial Fisheries
Fisheries Research
Act Comercial
Researchand
andDeuelopment
DeeIoent Act
Project
Project 1-86-R
1-86-R Contract
04-4-208-15 Contract No.
No. 04-4-208-15
Segment No.
No. 11 Segment
June 1974
1974 June
TABLE
CONTENTS TABLE OF
OF CONTENTS
Page
Page No.
~().
INTRODUCTION.
INTRODUCTION.
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INTERTIDAl
INTERTIDAL.AI~D
AND SUBTIDAL
SUBTIDAL CLN4
CLAM PUUfTING
PLANTING SURVEYS,
SURVEYS .•
Methods.
Methods. • • • • • • . • • • • . • • .
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1 Location
Intertidal and
and Subtidal
Subtidal Clam
Clam Planting
Planting
ion of
of Suitable
Suitable Intertidal
S1 tes • • • • • • •
• • • ••
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Yaquina Bay • • • • • •
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Netarts B!y • • • • •
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Alsea
Bay .• • • • •
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AseaBay
• •
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Discussion . . · . • • • • • • •
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CLAM STUDIES. • . . · . . .
..... . ·..... • • ·. • • •
Methods. . . . . . · . . . . . . .
• • • • • • • • • • •
Clam Rearing • . as......
• • • · . a· a..
LaboratoryClamRearing.
.. .. . a
.· .. ·· a...
Field Studies •••••••••
Manila-Littleneck Clams.
• •• · . · . . · . . . . .
§ytter Clams • • • • • • • • • · . . .
·....
Results. . . . . . .
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Resul ts ••••
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Results.
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Yaguina Bay .
Netarts Bay .
CLAM STUDIES.
Methods.
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15 Laborator~
Field Studies
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Results.
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u.ter Clans .
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• • • • • •........
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LaboratoryClamRearing
Laborato~a
Clam Rearing
••• •
Fte1d Studies
Stu ies .• •. • • •
• • • •
Field
Clams .......
•Nanila
fianila Littleneck
Littleneck Clams
·.• • • • •
Discussion • • • • •
a ...... *· . . . . . . . . . . .
Laboratory
Clam Rearing
LaboratoryClamRearing.
·. .......
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Field Studies • • • • • • •
·..
· . .• .• .• . .
~lani1a Littleneck
L1tt1eneck Clams
Clams. . . . . . . .
Manila
. .. . .. ..
Butter Clams • • • •
·...
ABALONE
ABALONE STUDIES
STUDIES • • • • • • · . .
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Methods •••
· . . . . . . . . . . . . . .a. .........
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Abalone Spawning•••
AbaloneSpawning.
Whale
Cove Abalone. • ••• · . . . .........
WhaleCoveAbalone
..
Resu1 ts. • • • • • • • • • · . .
·* ........· ...
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Abalone Spawning. •
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Whale Cove Abalone. . . . . . . . . .............
WhaleCoveAbalonea.....a
Discussion
Discussiona• . . . . . . . · . .
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Abalone Spawning. · . . . .a ......... a· .
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LITERATURE CITED. • • • • • · . ·a ...... a• •a ...... a· . . .
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Butter
Clams (, • • • • • • • •..• • ..........
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ButterClami%
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Discussion
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Butter Clams
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Abalone Spawning.
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Abalone Spawni ng
LITERATURE CITED.
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ReSU1tS.
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Methods.
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20
20 LIST OF
OF FIGURES
FIGURES LIST
Page
No.
Page No.
Figure No
Figure
No.
1
1
Lower
Bay Clam Beds .•
LowerBayClamBeds
......................
22 22
Cockle
Beds •...................
Cockle Clam
Clam Beds
3
3
3
3
Gaper Clam
Clam Beds
Beds.
Gaper
........................
4
4
4
4
Substrate
Types.
SubstrateTypes
.......................
6
6
55
Vegetation
Vegetation
66
Area
ClamClam
Beds Beds
Surveyed.
Areaand
and
Surveyed ..................
8
7
7
j'1anil a Li ttl eneck Clam Beds.
iianilaLittleneckClamBeds
..................
9
9
8
B
Substrate
Types ••
Substratelypes
........................
10
10 9
9
Vegetation
Vegetation
•..........................
. •
11 11
10
10
Area
ClamClamBed
Bed Surveyed
•
Areaandand
Surveyed
..................
12
12 11
11
Substrate Types.Types
• • • • ........................
• •
Substrate
13
13 12
12
Growth
Curve of
Butter Clams
Clams Planted
Planted on
the Breakwater,
Breakwater, Yaquina
Growth Curve
of Butter
on the
Yaquina
Bay. Vertical
Indicate Range
in mm.
• • • • • • . • ••
Vertical Lines
Lines Indicate
Range in
nn..........
. 17
17 Bay.
•.............
• •
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7
7
LIST
LIST OF
OF TABLES
TABLES Page No.
Ikr
Table No. 11 Comparison of
of Mean
Increase of
Comparison
Mean Shell
Shell Length
Length Increase
of Manila
Manila Littleneck
Littleneck
2
Growth
and Survival
Survival of
of Manila
Manila Littleneck
Littleneck Clams
Clams in
in Experimental
Experimental
Growth and
Plots on
on Breakwater,Yaquina
Breakwater,Yaquina Estuary
Estuary .
• • • • • • . . • • • • • 16
Plots
..............
16
3
3
Growth and
and Survival
Clams Planted
Planted on
the Breakwater
Growth
Survival of
of Butter
Butter Clams
on the
Breakwater 2
Clams Held
Tube
andand
Partitioned
Tray.Tray
• • ........
• • . ••
Clams
Held ininRearing
Rearing
Tube
Partitioned
September 1970 . • . •.........
• • . . • • •.
• . ..............
• • • • • • • • • • •
September1970
15
15
16
16
CLAM-ABALONE STOCK
FEASIBILITY STUDY
CLAM-ABALONE
STOCK SUPPLEMENTATION
SUPPLEMENTATION FEASIBILITY
STUDY INTRODUCTI ON
Of~ INTRODUCTI
The
objectives of
of this
this study
study were
were to
to locate
locate suitable
suitable intertidal
intertidal and
and subtidal
subtidal
The objectives
clam planting
sites and
to determine
the feasibility
of planting
planting laboratorylaboratory­
clam
planting sites
and to
determine the
feasibility of
spawned clams
spawned
clams. Criteria
Criteria used
used to
the suitability
potential clam
to determine
determine the
suitability of
of potential
clam
planting
sites included:
included: an
evaluation of
of species
species of
of clams
clams indigenous
indigenous to
to the
the
planting sites
an evaluation
survey area
type of
the survey
survey
area and
and the
the type
of substrate
substrate and
and vegetation
vegetation within
within the
survey area.
area
Major
in Yaquina
the distribution
bay clams
Major emphasis
emphasis was
was in
Yaquina Bay
Bay to
to evaluate
evaluate the
distribution of
of bay
clams
and
potential for
for planting
planting laboratory-spawned
laboratory-spawned clams.
clams. In
intertidal
and potential
In addition,
addition, intertidal
surveys
initiated on
on Alsea
Alsea and
and Netarts
Netarts bays.
bays.
surveys were
were initiated
Work
improve our
techniques to
to mass
Work continued
continued during
during the
the year
year to
to improve
our techniques
mass culture
culture
Manila littleneck
littleneck clams
clams Venerupi-s
VenePUpis phiZippinarium.
clams
Manila
Laboratory-spawned clams
phi.-li-ppi.nartum Laboratory-spawned
were planted
planted in
in test
test plots
plots in
in several
several areas
areas of
of Coos,
Coos, Coquille,
Coquille, and
and Netarts
Netarts
were
bays.
bays.
WTERTIDAL Aim
SUBTIDAL CLAM
CLAI'1 PLANTING
PLANTING SURVEYS
SURVEYS
INTERTIDAL
AND SUBTIDAL
t·1ETHODS
METHODS
Location
Location of
of Suitable
Suitable Intertidal
Intertidal and
and Subtidal
Subtidal Clam
Clam Planting
Planting Sites
Sites
1973 fiscal
fiscal year
(Osis and
and Gaumer,
Gaumer, 1973)
1973) were
were
Techniques developed
developed during
the 1973
Techniques
during the
year (Osis
used
having potential
used to
to locate
locate intertidal
intertidal and
and subtidal
subtidal areas
areas having
potential for
for planting
planting
laboratory-produced
juvenile clams.
clams. We
We used
used the
the presence
presence of
of clams
clams (both
(both interinter­
laboratory-produced juvenile
tidal
tidal and
and subtidal),
subtidal), substrate
substrate type,
type, and
and depth
depth of
of water
water as
as criteria
criteria for
for determining
determining
having potential
potential for
for planting
planting clams.
clams.
areas having
areas
Location of
of clam
clam beds
beds on
intertidal tideflats
tideflats was
was accomplished
accomplished by
by establishing
establishing
Location
on intertidal
transect
lines across
across each
each of
of the
the tideflats
tideflats. Observations
Observations made
made at
at established
established
transect lines
stations
included species
in the
stations along
along the
the transect
transect line
line included
species of
of clams
clams in
the area,
area, relative
relative
density of
of each
each species
species of
of clam,
claln, substrate
substrate type,
type, and
and vegetation
vegetation type
type. Similar
Similar
density
observations were
were made
made subtidally
subtidally with
with the
the use
use of
of scuba
scuba gear.
gear.
observations
RESULTS
RESULTS
Yaquina
Yaquina Bay
Bay
Figure 11 shows
shows the
the distribution
distribution of
of bay
bay clams
clams (butter,
(butter, &z'idamus
S~idOmus giganteus;
giganteua;
Figure
cockle,
CUnocardium nuttaUii"
gaper,
Tresus
VenePUpis
cockle, Cii..nocardi.um
nuttallii-,
gaper,
Tresuscapa:c;
capax,native
native littleneck,
littleneck, Venerupi.e
Softshell
staminea; and
and piddock,
piddock, Zirfasa
Zirfaea pil8bryi)
pilsbryi) in
lower Yaquina
Yaquina Bay.
Bay. Softshell
in the
the lower
staminea;
clam
(MYa arenaria)
this species
clam (Mya
arenaria) beds
beds of
of the
the upper
upper bay
bay are
are not
not shown
shown although
although this
species
is
both shores
shores upstream
upstream of
of King
King Slough
Slough and
and Sally's
Sally's Bend
Bend to
to Toledo.
Toledo.
is found
found along
along both
Cockle
principal species
found in
in the
the lower
lower
Cockle and
and gaper
gaper clams
clams were
were the
the principal
species of
of clams
clams found
In the
the intertidal
bay
(Figures 22 and
and 3)
3). In
intertidal areas,
areas, both
both species
species of
of these
these clams
clams
bay (Figures
were generally
generally at
at densities
densities of
of less
less than
than 11 per
per square
square foot.
foot. Subtidally
Subtidal1y gaper
gaper
were
clams
containing clams
clams were
were considerably
considerably more
more abundant
abundant with
with extensive
extensive areas
areas containing
clams
in excess
per square
several areas
having concentrations
in
in
excess of
of 5
5 per
square foot
foot and
and with
with several
areas having
concentrations in
subtidal areas
excess
of 10
10 per
per square
square foot.
foot. Few
Few subtidal
areas contained
contained cockle
cockle clams
clams in
in
excess of
per square
square foot.
foot.
excess
of I1 per
excess of
HEWPORT
WEWPORT
SALLY'S BEND
BEND
SALLY1S
SOUTH BEACH
LEGEND
LEGEND
:j
CLAM BEDS
CLAM
BEDStl!lj}l!ljii~~~jljill~l~li
L
tWIW1l
HWY.. 1
1
"0
-o
~
C,
.....
-I
KING SL
YAQUINA
YAQUII1A
•
,
N
"'T'I
.....
n
C,
o0
n
I'T'l
:J>
:z
TOLEDO 33 Miles--M;les--­
TOLEDO
YAQUINA BAY
BAY
YAQUI4A
o0 1000
1000
3000
5000 FEET Lower
am Beds
Figure
Lower Bay
Bay Cl
Clam
Beds
F i gure 1.
1.
,r
----.......... NEWPORT
[l*1Ikhl
SALLY'S BEND
BEND
SALLY'S
SOUTH BEACH
LEGEND
LEGEND
K~'Y. 101
101
HUY,
CLAM BEDS
CLAf4
BEDS
;g
--
,,:;:i;:::;:::::",::::,::,
Jljf.ft~H~;firf!:
nC)
,
"Tl
1
'-S
KING SLOUGH
SLOUGH
KING
n
C,
,
w
YAQUINA
YAQUT NA
o
n
C,
m
£!
:2:
YAQUINA
BAY
YAQUINA BAY
oO
1000
1000
I
3000
3000
,
TOLEDO
miles --­
TOLEDO 33 miles
5000
5000
,
Feet
Feet Figure 2.
2.
Figure
Cockle Clam
Clam Beds
Beds Cockle
~
NEWPORT
tI'1tli SALLY'S
BEND w:iiij
1JHi:IT,1
SOUTH
BEACH IDAHO POINT
LEGEND
LEGEND
CLAM
CLAMBED
BED DENSITIES
DENSITIES
f~~~jH~ti\~Nff)1 << 5/ft.
51 ft. 2
HWY. 101
~
.....
("")
r)
fi>i'I:::::
''''''''''''''''''''1
i i':':':m:::::;
I-.
."
-n
....... > 6/f
61ftt.22
>
.
I
Ii
~
('")
o
('")
siEe1*,1IIe:l
KING
SLOUGH
fT'I
»
t
ti
YAQUINA
AQUI NA :z
o
TOLEDO
TOLEDO 33
YAQumA
BAY
YAQUINA BAY
l?OO 30?O 5090 FEET miles-----miles
------
RIVER BEND
Figure
Clam Beds.
Figure 3. Gaper
Gaper Clara
~
-5­
-
Figure
the four
four principal
principal substrate
substrate types
types found
found in
in the
the survey
survey area.
area.
Figure 4
4 shows
shows the
were observed
observed at
at many
many of
of the
the sample
sample stations.
stations. The
Several
substrate types
types were
Several substrate
The
principal
each station
station is
is shown
shown. Only
two or
or more
principal material
material at
at each
Only when
when two
more different
different
substrate types,
types, in
in nearly
nearly equal
encountered did
show them
them
substrate
equal quantities,
quantities, \'1ere
were encountered
did ~/e
we show
overlapping on
on the
the map.
map.
overlapping
A preference
preference for
for sand,
sand, gravel)
gravel, or
or shell
shell substrate,
substrate, or
or aa combination
combination of
of these
these
A
was
found for
for cockle
both intertidally
intertidally and
and subtidally
subtidally whereas
was found
cockle and
and gaper
gaper clams
clams both
whereas
mud
substrates contained
contained few
few of
of these
these clams,
clams.
mud substrates
The
of aquatic
aquatic vegetation
vegetation in
in Yaquina
Yaquina Bay
Bay is
is shown
shown in
in Figure
Figure 5.
5.
The distribution
distribution of
Eel
grass (Zo6tera
(Zostepa maPina)
the principal
principal species
species found
found followed
followed by
by rockweed
rockweed
Eel grass
marina) was
was the
(Pucus
the green
green alga
alga (Enteromorpha
(Entepomoppha sp.).
sp.). The
importance of
of these
these
(Fucus fUl'aatus),
furcatus), and
and the
The importance
setting and
rearing of
aquatic
plants, especially
for the
the successful
successful setting
aquatic plants,
especially eel
eel grass,
grass) for
and rearing
of
juvenile
clams
can
be
seen
when
the
distribution
of
bay
clams
and
plants
are
juvenile clams can be seen when the distribution of bay clams and plants are
compared. This
applies especially
especially to
to the
the intertidal
intertidal and
and shallow
shallow subtidal
subtidal areas
areas
compared.
This applies
since
of water
water controls
controls the
the growth
growth of
of these
these plants.
plants.
since depth
depth of
Bay
Netarts Bay
Netarts
Clam
surveys on
on Netarts
Netarts Bay
Bay are
are incomplete.
incomplete. Survey
of the
the intertidal
intertidal tidetideClam surveys
Survey of
flat
of the
the main
main channel
channel was
was nearly
nearly completed
completed during
during the
the year
year (Figure
(Figure 6)
6).
flat west
west of
Nany
including butter,
native and
Many species
species of
of clams
clams including
butter, cockle,
cockle, gaper,
gaper, and
and native
and Manila
Manila
littleneck clams
locations mapped
for the
the tideflat
tideflat. Densities
Densities
littleneck
clams were
were observed
observed and
and locations
mapped for
of clams
clams were
generally less
less than
than 11 per
per square
square foot
foot for
for each
each species.
species. Of
parti­
of
were generally
Of particular
interest was
littleneck clams
cular interest
was the
the discovery
discovery of
of two
two areas
areas containing
containing Nanila
Manila littleneck
clams
(Figure
7). This
This discovery
timely since
since we
we were
were looking
looking for
for an
an area
area to
to
discovery was
was timely
(Figure 7)
evaluate
in an
area already
evaluate mass
mass planting
planting of
of laboratory-produced
laboratory-produced Manila
Manila clams
clams in
an area
already
containing
Manila clams.
clams.
containing Manila
Substrate types
types for
for the
the tideflat
tideflat are
are shown
shown in
in Figure
Figure 8.
8. Sand
Sand was
\I/as the
the principal
principal
Substrate
mud mixed
mixed with
with sand
sand being
being abundant
abundant in
in the
the upper
upper bay.
bay.
material observed
observed with
material
with mud
Generally
located in
in areas
containing
Generally the
the major
major concentrations
concentrations of
of clams
clams were
were located
areas containing
substrate. Cockle
especially abundant
abundant in
in areas
areas composed
composed
aa sand-mud
Cockle clams
clams were
were especially
sand-mud substrate.
Manila clams
of
sand-shell substrate.
substrate. Hanila
clams were
were found
found in
in aa substrate
substrate of
of compacted
compacted
of a
a sand-shell
sand
and mud.
mud.
sand and
Vegetation
primarily to
to the
the upper
upper estuary
estuary where
Vegetation on
on the
the tideflat
tideflat is
is confined
confined primarily
where
extensive
the tideflat
tideflat from
from the
the shore
to the
the
extensive areas
areas of
of dense
dense eel
eel grass
grass cover
cover the
shore to
channe1 (Figure
(Figure 9).
g). AA major
major part
part of
of this
this area
area contained
contained few
few clams
clams but
but ghost
ghost
channel
(Callianassa aaZifoPniensis)
caZiforniensis) and
and mud
mud (Upogebia
(upogebia pugettensis)
pugettensis) shrimp
shrimp were
were
(CaZZianassa
abundant.
abundant.
Bay
Alsea Bay
Alsea
The tideFigure
10 shows
the only
only area
area surveyed
surveyed on
on Alsea
Alsea Bay
Bay during
during the
the year.
year. The
tide­
Figure 10
shows the
flat contains
number of
and aa dense
population of
ghost
flat
contains a
a small
small number
of cockle
cockle clams
clams and
dense population
of ghost
shrimp.
Sand
is the
the predominant
predominant substrate
substrate type
type in
in the
the area
area (Figure
(Figure 11).
11).
Sand is
shrimp.
Enteromorpha sp.
sp. was
was the
the only
only vegetation
vegetation observed
observed on
on the
the tideflat.
tideflat.
Enteromorpha
1'
(
.IP
\.:.;
SALLY'S
BEND
SALLY'S BEND
:1
LEGEND
LEGEND
SOUTH BEACH
SOUTH BEACH
Gravel-Rock
Gravel-Rock
I
J
rL....... ,_j,'1
IDAHO P6Ii'T
•
• f , ••
~
,
t
•
t
••
I
,
•
Sand
··:1
r4ud
HWY. 101
HWY
J..:U· . . . .,
~
i.;;'"
II I I Jill
nC,
.....
-n
-n
.....
n
J
Shell
Shell
J
'-4
C-)
YAQUINA
KING
SLOUGH
It4G SLOUGH
<=>
nC-)
I,,
rn
'"
I
)::>
2:
o0
Figure
4.
Figure 4.
YAQUII~A BAY
BAY
YAQUH4A
1000
3000
FEETI
I!EET
Substrate
Types
Substrate Types
TOLEDO 3 3miles---­
TOLEDO
miles----
5000
RIVER BEND
SALLY'S
BEND
SALLY'S BEND
SOUTH
BEACH
SOUTH BEACH
iiit:i'iiJiii
HWY.
1
1'Ol
LEGEND
j;
--
Vegetation Beds
Beds
n
1-.4
I
."
'oJ
'-4
("')
r)
YAQUINA
o
I
KING SLOUGH
n
I'T1
rn
»
::z
TOLEDO
3 3miles--­
TOLEDO
miles--YAQUIHA
BAY
YAQUIW\ BAY
11II
o
O
1000
3000
I
FEET
FEET
Figure
5. Yegetati
¥egetati on.
Figure 5.
5000
!
RIVER BEND
-8-
TI
LLA!100K COUNTY
TILLAIJOOK
COUNTY
BOATRN1P
RAf,IP
'\\JQOAT
/
:'
PACIFIC
PACIFIC OCEAN
OCEAN
/-
II
KING
REALTY
KING REALTY
......
I
\
I
J
.
CREEK
~'JHISKEY
WHISKEY CREEK
,I
,
I
II
IJ
I
I
I
I
J
,;
/
I
,
1''
I
I/
NETARTS BAY
NETARTS
BAY
3000
3000
I
FEET
t LL I
oo
,_
I
t
/
LEG END
LEGEND
E:t>:~::;:::::::~::::<':::::;::~f Area
Area Surveyed
Surveyed
Clam
'tiwrH£litHlfHfii[[rHiI1tj Cl
am Beds
Beds
CAPE LOOKOUT
STATE PARK
Figure
Figure 6.
6. Area
Area and
and Clam
Clam Beds
Beds Surveyed.
Surveyed. -9­
r~ETARTS
H
ETARTS
\
(7
TI LLAHOOK COUNTY
TILLA1OOK
, BOAT RAHP
f
\
\
\
i \)j
\
[\
I
11
;
I
I
I:
I1
/
PACIFIC OCEAN
OCEAN
PACIFIC
I
I \
I
\
o
,
'\\
"\
i
..,
\
\
\
I
/
tii
I'
I
J
/'
/
5Ef\
KING
KIIJG REALTY
REALTY
I I
/,'1)
I,
I f
I
I
I
\
\
\
CJ
)
1I
il
I I
I
I
j
)
II
'"
II
I/
1
)
I
/
I
I
I
I
....
,jff
.,,/ /
j
cy
/1
//
I/
o
0
I
-
I \
10'
/
\
0
2 WHISKEY CREEK
\
I,
JI
/
,\
I
1
1
/
/
t
,
I
I
I
f
I
1/
I//
J
,
/--­
-
\
'I
I
NETARTS BAY
I4ETARTS
BAY
O
0"
//
,'
FEET
FEET
,3,000
3,000
1/
/
LEGEND
LEGEND
tHBf!if)[)I!!l
1<1anilClam
a Cl amBeds
Beds
iI Manila
a0 Clam
Clam Planting
Planting Sftes
Sites (1973)
(1973)
CAPE
PARK
CAPE LOOKOUT
LOOKOUT STATE
STATE PARK
Figure
Figure 7.
2. Manila
Manila Littleneck
Littleneck Clam
Clam Beds.
Beds.
-10­
,­
--
I
NETARTS
'­
COUNTY
11LL~tJ\OOK
TILLMOOK COUNT'(
RAMP
\ 'B
B T
1" RAi'W
:
:
KING
REAL1Y
KING REALTY
PACIfIC
PACIFIC
OCEAI4
OCEAN
CREEK
~!HISKEY
WHISKEY CREEK
NE1ARtS BAY
SAY
oNETARTS 3000
3000
0
~
FEET
I
\
LEGEND
LEGEND
Sand
/
Mud
Shell
1TI1JL1 '
CAPE
LOOKOU1 STATE
S1A1E
CAPE LOOKOUT
PARK
PARK
Types.
Figure 8.
B. Substrate
Substrate 1ypes.
Figure
I
-11-11­
" -.
--
/
NETARTS
TILLA~DOK COUNTY
couriTY
TILLAOOK
)
BOAT RAMP
7'
1'
)
WI
/
//
\
I
\
\
\
I
I
\
\
\
\
.
\ I
\
KING REALTY
REALTY
\
\\
J
PACIFIC OCEAN
OCEAN
J'
r
Jr
\
,
/
"
1,-'
I/'I
I
/
WHISKEY CREEK
\1
I
/
I
1)
/
1// /
-
//
f1'
/"'
I
/
o
0
I
-
II,
!t
I
FEET
FEET
1
7
NETARTS BAY
BAY
NETARTS
3000
LEGElm
LEGEND
if
CAPE LOOKOUT STATE PARK
Figure 9.
9.
Figure
Vegetation.
Vegetation Beds
I
-0
»
101
n
......
."
......
n
0
n
m
»
z
I
.....
N
I-.
I
<
o
ALSEA BAY
3000
FEET
101 LEGEND
,.<.;.......
. .:.:.:.$...:......:..:...;:.,:.')..........;
. .;."1
~
~?.:
Area Surveyod
'­
f::tt¥'::ri""'T'"
i:i:::::~;.w,$,if'::: COC k1eel
am Bed
,jatii
uvu
Figure 10.
Figure
10. Area
and Clam
Clam Bed
Bed Surveyed.
Surveyed.
Area and
101
"'0
);>
(')
C-)
b-I
......
"'TI
-n
C-)
0
(')
C-)
£T1
);>
.:..:
I
__:,,'c:7'S4 1
A
\
~\
\))
o
ALSEA BAY
3000
FEET
LE (£fm
r
k:::::;*~~:~::::~~~::~::;;:;J
n .
Sand
,,',
Sand
and Mud
Sand ana
ua
Figure
11. Substrate Types.
Types.
Figure 11.
I
)l;;)
....... W
I
-14-14­
DISCUSSION DISCUSS I ON
Results
important for
Results of
of our
our surveys
surveys indicates
indicates that
that substrate
substrate type
type is
is important
for the
the
different species
species of
of bay
bay clams.
clams. Intertidally,
cockle clams
clams
establishment of
of different
establishment
Intertidally, cockle
were more
common in
in aa sand,
sand. sand-mud,
sand-mud, or
or sand-shell
sand-shell substrate.
substrate. Gaper
clams had
had
were
more common
Gaper clams
a similar
similar preference
preference although
fewer were
found in
in aa pure
pure sand
sand substrate
substrate than
than the
a
although fewer
were found
the
cockle.
Subtidally, both
both species
species were
more abundant
abundant in
in aa substrate
substrate of
of sand
sand and
and
cockle. Subtidally,
were more
gravel mixed
mixed with
wi~h shell
shell. Butter
and (iaiila
Manila littleneck
in
gravel
Butter and
littleneck clams
clams were
were found
found mainly
mainly in
a substrate
substrate of
of compacted
compacted mud
mud and
and sand.
sand.
a
Vegetation appearedto
beaess significant
significant factor
factor than
than substrate
substrate type
type for
for governing
governing
Vegetation
appearedto beaèss
the
of clams.
clams. In
In several
several areas,
gaper and
and cockle
cockle clams
clams were
were located
located
the distribution
distribution of
areas, gaper
in
in eel
eel grass
grass beds
beds although
although it
it was
was not
not determined
determined whether
whether the
the substrate
substrate type
type or
or
the
eel
grass
was
the
principal
factor
for
the
clams
setting
in
these
areas.
the eel grass was the principal factor for the clams setting in these areas.
CLAM STUDIES
STUDIES
CLAM
1*I1IaD1
I~ETHODS
Laboratory Clam
Clam Rearm
Rearing
Laboratory
rearing clams
Basic techniques
techniques and
Basic
and procedures
procedures for
for spawning
spawning and
and rearing
clams \'Jere
were not
not altered
altered
from
(Lukas 1972,
1972. 1973).
1973). A
new rearing
rearing device
device was
was
front those
those used
used in
in previous
previous years
years (Lukas
A new
constructed and
and tested
tested to
to determine
determine if
clams grew
grew as
as well
well or
or better
than those
those
constructed
if clams
better than
in
rearing tray.
tray. This
device consisted
consisted of
of aa 15.1
15.1 cm
cm diameter
diameter plexiplexi­
in our
our standard
standard rearing
This device
glass tube,
tube. 72
72 cm
cnl long.
long. Two
screened partitions
partitions (1.4
(1.4 mm
nylon mesh)
placed at
glass
Two screened
mm nylon
mesh) placed
at
each
the tubed
tubed created
created aa compartment
compartment to
to hold
hold juvenile
juvenile clams.
clams. The
rearing
each end
end of
of the
The rearing
tube was
in at
the bottom
bottom at
tube
was placed
placed upright
upright and
and water
water pumped
pumped in
at the
at a
a rate
rate of
of 7-8
7-8
thousand Hanila
clams were
were held
held in
in the
the rearing
rearing tube.
tube.
liters/minute. Four
Four thousand
Manila clams
liters/minute.
Field Studies
Field
Studies
Clams. Spot
on the
the breakwater
breakwater plot
plot in
in Yaquina
i'lanila
Littleneck Clams.
Spot samples
samples were
were made
made on
Yaquina
Manila Littleneck
Estuary.
area was
was planted
planted with
with 390,000
390,000 clams
clams in
in the
the summer
summer of
of 1972.
1972. Several
Several
This area
Estuary. This
This
planted with
with clams
clams of
of various
various ages
ages and
and mean
mean shell
shell lengths.
lengths. This
subplots
subplôts were
were planted
area,
area, resulting
resulting from
from dredge
dredge spoil
spoil deposition,
deposition, consists
consists predominantly
predominantly of
of walnut
walnut
size
(ranging from
size river-run
river-run gravel
jravel (ranging
from pea
pea to
to baseball
baseball size)
size) mixed
mixed with
with sand.
sand
from the
the horizontal
horizontal and
and the
the
Approximately two-thirds
two-thirds of
the area
area slopes
slopes 7-8°
7-8 0 from
Approximately
of the
res tis
1eve 1 .
rest
is level.
Experimental plots
in three
Experimental
plots of
of laboratory-reared
laboratory-reared r'lanilas
Manilas were
were established
established in
three
estuaries; Netarts,
estuaries;
Netarts. Coos,
Coos. and
and Coquille.
Coquille.
In July
and August
1973, we
we established
established plots
plots in
in six
six different
different areas
areas in
in Netarts
Netarts
In
July and
August 1973,
Estuary
intertidal sampling
the existence
Estuary after
after the
the intertidal
sampling revealed
revealed the
existence of
of a
a small
small population
population
of
natural-set Manilas.
f4anilas. We
He planted
planted 10,625
10,625 juvenile
juvenile Manila
r'lanila clams
clams in
in these
these test
test
of natural-set
plots. One
plot was
in one
the two
two areas
areas where
One plot
was established
established in
one of
of the
where f1anila
Manila adults
adults
plots.
were found.
found. Five
north and
and south
south of
of the
the natural
natural Manila
{'1anila populations,
populations,
Five other
other areas,
areas, north
were
were selected
selected for
for experimental
experimental plantings
plantings to
to evaluate
evaluate their
their potential
potential for
for future
future
were
f4anila
introductions. Five
the areas
had substrate
substrate material
Five of
of the
areas had
material consisting
consisting of
of
Manila introductions.
- 15-15­
firm sand
sand and
and mud
mud with
with aa thin
thin layer
layer of
of silt
silt on
on top.
top. The
sixth area
covered with
with
firm
area was
was covered
The sixth
growth of
of eel
eelgrass.
The plots
plots were
\1ere planted
planted iith
wi th clams
clams averag
i ng 7.3
7.3 mm
aa dense
dense growth
grass
The
averaging
mm
(range
3.6-11.3
mnl) and
foot.
(range 3
6-11 3 nuii)
andatata adensity
density of
of 50
50 clams/square
clams/square foot
Two
clam plots
plots were
were established
established in
in Coos
Coos Estuary
Estuary in
in August
August 1973.
1973. The
The site
site
Two i4anila
Manila clam
selected
island on
selected for
for the
the two
two plots
plots was
was on
on a
a dredge-spoil
dredge-spoil island
on the
the west
west side
side of
of the
the
bay and
The
sub­
bay
and approximately
approximately 1.3
1 3 miles
miles upstream
upstream from
from the
the mouth
mouth of
of the
the estuary.
estuary
The substrate
of aa gravel-sand
gravel-sand mix
mix with
with broken
broken gravel
gravel predominating.
predominating. The
The two
two
strate consisted
consisted of
10
by 20-foot
20-foot plots
plots were
were planted
planted with
with juvenile
juvenilei'ianilas,
j.janilas, averaging
at aa
10 by
averaging 7.1
7.1 mm
mm at
50 clams/square
clams/square foot.
foot.
density
of 50
density of
10 by
by 20-foot
20-foot plot
plot was
was established
established in
in Coquilie
Cqquil"le Estuary
Estuary in
in August
August 1973
1973 in
in aa small
small
A 10
A
intertidal area
area near
near the
the mouth.
mouth. The
The substrate
substrate in
in the
the area
area consisted
consisted of
of aa coarse
coarse
intertidal
mix. The
7.1 mm
planted at
sand-fine
gravel mix,
sand-fine gravel
The l~ani1a
Manila clams
clams averaged
averaged 7.1
mm and
and were
were planted
at a
a
density of
of 50/square
50/square foot.
foot.
density
Clams.
Butter
Butter Clams.
In
1970, 600
600 juvenile
juvenile laboratory-reared
laboratory-reared butter
butter clams
clams
In September
September 1970,
The
3 by
by 10-foot
10-foot plot
plot
The 3
was near
near the
the base
base of
of aa breakwater
breakwater in
in the
the lower
lower estuary.
estuary. The
The substrate
substrate consisted
consisted
was
mix. The
The clams
clams were
were 22
22 months
months old
old when
when planted
planted and
and mean
mean shell
shell
of
gravel-mud mix.
of a
a gravel-mud
length
20 nn.
mnl. They
They were
an enamel
enamel paint
paint to
to distinguish
distinguish them
them from
from
length was
was 20
were n~rked
marked with
with an
natural
butter clams
clams also
also found
found in
in the
the area.
area.
natural set
set butter
(Saxidomus
giganteus) were
were planted
planted in
in Yaquina
Yaquina Estuary.
Estuary.
(Saxidornus giganteus)
RESULTS
RESULTS
Laboratory
Rearing
Laboratory Clam
Clam Rearing
Manila littleneck
littleneck clams
clams reared
reared in
in the
the plexiglass
plexiglass tube
tube had
had aa slightly
slightly faster
faster
Manila
growth rate
rate than
than the
the control
control group
group held
held in
in aa partitioned
partitioned tray
tray (Table
(Table 1).
1). For
growth
For
the
the first
first few
few weeks
weeks of
of the
the test,
test, the
the screen
screen used
used to
to seal
seal the
the ends
ends of
of the
the tube
tube had
had
a mesh
size of
of 0.75
0.75 mm
mnl (side
(side to
to side).
side). This
This mesh
mesh was
was easily
easily clogged
clogged with
with detritus
detritus
a
mesh size
occurring in
in the
the seawater.
seawater. Changing
1.4 mm
occurring
Changing to
to a
a screen
screen with
with 1.4
mm mesh
mesh size
size reduced
reduced the
the
problem.
problem.
Table 1.
Date
6-28-73
6-28-73
7-12
7-12
7-26
7-26
8-9
8-9
8-23
8-23
9-6
9-6
9-18
9-18
10-11
10-11
10-18
10-18
Comparison
Length Increase
Increase of
Comparison of
of I,jean
Mean Shell
Shell Length
of
r·1anila Littleneck
Littleneck Clams
Clams Held
Held in
in Rearing
Rearing Tube
Tube
Manila
and Partitioned Tray.
r~ean Shell Length (mm)
Partitioned Tray
Rearing Tube
3.4
3.4
4.1
4.1
5.3
5.3
6.3
6.3
7.4
7.4
8.0
8.0
8.3
8.3
8.7
8.7
8.5
8.5
3.4
3.4
4.0
4.0
4.6
4.6
5.7
5.7
6.0
6.0
6.7
6.7
7.3
7.3
7.6
7.6
7.6
7.6
Field Studies
Studies
Field
Sampling of
of the
Clams. Sampling
the experimental
experimental plot
plot on
on the
the breakwater
breakwater in
in
iilanila
ilanila Littleneck
Littleneck Clams.
Yaqu"ina Estuary
Yaquina
Estuary revealed
revealed that
that survival
survival of
of the
the juvenile
juvenile Manilas
Manilas was
was dependent
dependent
-16­
upon
whether the
upon whether
the substrate
substrate was
was level
level or
or sloped
sloped (Table
(Table 2),
2). However,
However, one
one group
group of
of
clams
(lot number
number 69-sm)
in one
this and
clams (lot
69-sm) in
one area
area did
did not
not demonstrate
demonstrate this
and other
other factors
factors
may have
may
have influenced
influenced survival
survival. With
With the
the exception
exception of
of group
group 69-sm,
69-sm, survival
survival of
of
clams
the level
level area
30.4% while
clams on
on the
area ranged
ranged from
from 20.9
20.9 -- 30.4%
while survival
survival on
on the
the sloped
sloped area
area
ranged
3.8 -- 4.1%.
4.1%. Survival
of juvenile
juvenile Iianilas
~'lani1as of
ranged from
from 3.8
Survival of
of group
group 69-sm
69-sm located
located on
on
the level
level area
area ranged
the
ranged from
from 3.3
3.3 -- 3.8%
3.8%, slightly
slightly better
better than
than those
those of
of the
the slope
slope
which
ranged from
from 0.6
0.6 -- 2.9%.
2.9%.
which ranged
Table
2. Growth
Growth and
and Survival
Survival of
of t4anila
itJanila Littleneck
Littleneck Clams
Clams in
Table 2.
in Experimental
Experimental Plots
Plots on
on
Breakwater;
Breakwatei, Yaquina
Yaquina Estuary.
Estuary.
Mean Shell
Mean
Shell Length
Length (mm)
rmm}
Percentage When
Experimental
When
Experimental Substrate
Substrate Percentage
When
Approximate
in
When
Months in
Approximate ~40nths
Clam Group
Clam
Grou~
Gradient Survival
Planted
Survival
Planted Sampled
Increase
Height the
Plot
Gradient
Increase Tidal
Tidal Height
the Plot_
Sam~led
#11
#11
#11
#11
71-12B
71-12B
71-11A
71-hA
71-9(lg)
71-9(lg)
71-9(sm)
71-9(sm)
69 srn-6
69
sm-G
55
4
4
33
2
2
11
Level
Level
Slope
Slope
Level
Level
Slope
Slope
Level
Level
Level
Level
Level
Level
Level
Level
Slope
Slope
Slope
Slope
Slope
Slope
SloQe
Slope
20.9
20.9
3.8
3.8
21.4
21.4
4.1
4.1
24.6
24,6
30.4
30.4
3.8
3.8
3.3
3.3
2.1
2.1
2.9
2.9
1.2
1.2
0.6
0.6
5.3
5.3
5.3
5.3
6.1
6.1
4.1
4.1
10.6
10.6
6.7
6.7
6.6
6.6
6.6
6.6
6.6
6.6
6.6
6.6
6.6
6.6
6.6
6.6
10.4
10.4
11.
7
11.7
12.0
12.0
11.8
11.8
20.8
20.8
16.1
16.1
13.0
13.0
14.6
14.6
14.7
14.7
15.4
15.4
16.2
16.2
23.0
23.0
5.1
5.1
6.4
6.4
5.9
5.9
7.7
7.7
10.2
10.2
9.4
9.4
6.4
6.4
B.O
8.0
8.1
8.1
B.8
8.8
9.6
9.6
18.4
18.4
8.0
8.0
8.0
8.0
11.
0
11.0
11.0
11.0
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
12.5
4.0
4.0
3.2
3.2
3.8
3.8
3.3
3.3
4.0
4.0
4.0
4.0
3.6
3.6
3.8
3.8
3.8
3.8
3.7
3.7
3.3
3.3
2.9
2.9
One group
group of
of clams
clams (group
(group 71.9)
71.9) were
screen-sorted into
into two
two size
size groups
groups before
before
One
were screen-sorted
10.6 and
and 6.7
6.7 mm shell
shell
length.
After
12.5
months
in
the plot,
plot,
planting and
planting
and averaged
averaged 10.6
length.
After
12.5
months
in
the
the average
shell length
length of
of the
the "large"
1I1arge il group
group increased
increased 10.2
10.2 mm
mm and
and the
the "small"
IIsmallll
the
average shell
group
9.4 mm.
nm.
group 9.4
mm
Butter
Clams. The
The experimental
experimental butter
butter clam
clam plot
plot established
established near
near the
the base
base of
of the
the
Butter Clams.
Yaquina
Bay breakwater
break\vater in
in September
September 1970
1970 has
has been
been sampled
sampled twice
twice (Table
(Table 3).
3).
Yaquina Bay
3. Growth
Growth and
Planted on
on the
the Breakwater
Breakwater September
Table 3.
and Survival
Survival of
of Butter
Butter Clams
Clams Planted
September
Table
1970.
1970.
Date
Sampled
Bate Sampled
7-13-72
7-13-72
7-30-73
7-30-73
Mean Shell
Shell
Mean
Length
(mm)
Length (mm)
Percentage
Percentage
Survival
Survival
Age
of Clams
Clams
Age of
(~lonths
(Months))
Months
Months in
in
Plot
Plot
37.0
37.0
46.7
46.7
31.
7
31.7
46.7
46.7
44.S
44.5 57 57
22
22
34.5
34.5
The
The growth
growth of
of the
the clams
clams in
in this
this plot
plot has
has been
been less
less than
than that
that of
of a
a comparable
comparable group
group
planted on
planted
on the
the breakwater
breakwater in
in an
an artificial
artificial substrate
substrate plot
plot located
located about
about 100
100 yards
yards
away
(Lukas 1972)
1972) (Figure
(Figure 12).
12).
away (Lukas
-17-17­
70
70
Artificial substrate
substrate plot
plot (Lukas
(Lukas 1972)
1972)
----- Artificial
Base
of breakwater
Base of
breakwater plot
plot
I
J
60
60
-
I/",/'i
I
I-./'
50
-1
E
E
.
I
---
1
140
//1
1/1"
I
/
I'
I'
"
/
,­
20
,•
/
,Alams
planted
planted
/
/
/
/
/
10
•
/
­
,/
/
_~.~ Clams
Clams planted
planted -1--;-
I
I
I Ii_Ii
I I
II
Ii
I
12
12
66
Figure 12.
12.
Figure
I
18
1
24
24
i
I
I
lit
I
30
Honths
Months
36
42
48
I 1
Il
Ijj_
1
54
I
i
60
60
Growth Curve
Curve of
of Butter
Butter Clams
Clams Planted
Planted on
on the
the Breakwater,
Breakwater, Vaquina
Yaquina Bay.
Bay.
Growth
Vertical lines
lines indicate
indicate range
rangeininni1.
mm.
Vertical
DISCUSSION
DISCUSS ION
Laboratory
Clam Rearinçj
Rearing
Laboratory Clam
The plexiglass
plexiglass rearing
rearing tube,
tube, in
in which
which juvenile
juvenile clams
clams grew
grew at
at aa slightly
slightly faster
faster rate
rate
The
than controls,
to hold
hold and
than
controls, offers
offers the
the advantage
advantage of
of being
being able
able to
and rear
rear aa large
large number
number
of clams
clams in
in aa smaller
smaller space
space than
than the
the currently-used
currently-used trays.
trays. The
numbers of
of
of
The maximum
maximum numbers
clams
clams which
which could
could be
be held
held in
in this
this tube
tube and
and the
the optimum
optimum water
water flow
flow rates
rates were
were not
not
determined. Only
4,000 clams
clams were
\'1ere used
used in
in the
the initial
initial test.
test.
Only 4,000
determined.
Field Studies
Studies
Field
l'lanila
Littleneck Clams.
Clams. Survival
differences of
of clams
clams planted
planted on
on aa slope
slope and
and level
level
Survival differences
Manila Littleneck
been discussed
in aa previous
previous progress
progress report
report (Lukas
(Lukas 1972).
1972). The
The observation
observation
area
area has
has been
discussed in
related also
also to
to substrate
substrate type.
type. Higher survival
survival occurred
occurred on
on aa level
level
in 1972
in
1972 was
was related
-18­
area
poorer survival
area with
with a
a gravel
gravel substrate
substrate while
while poorer
survival occurred
occurred on
on a
a slope
slope area
area which
which
had aa sparse
sparse amount
amount of
of gravel.
gravel. The
The substrate
substrate composition
composition of
of the
the areas
areas sampled
sampled in
in
had
1973
1973 on
on the
the breakwater
breakwater in
in Yaquina
Yaquina Estuary
Estuary was
was consistent
consistent on
on both
both the
the slope
slope and
and
level.
Yet in
in 22 of
3 plots,
plots, there
there \<las
notable difference
difference in
in survival
survival between
between
level.
Yet
of 3
was a
a notable
the two
two gradients.
gradients. This
has aa southern
exposure and
and apparently
the
This area
area has
southern exposure
apparently wave
wave action
action
during
is disruptive
to scour
during winter
winter stroms
stroms on
on a
a sloped
sloped surface
surface is
disruptive enough
enough to
scour clams
clams out
out
of
the substrate,
even if
if it
it has
has aa protective
protective layer
layer of
of gravel
gravel on
on it.
it.
of the
substrate, even
Another observation
observation from
from this
this plot
plot was
was the
the comparison
comparison of
of growti
growth of
of two
two groups
groups of
of
Another
clams
but of
lengths when
planted. The
increase
clams of
of the
the same
same age
age but
of different
different mean
mean lengths
when planted
The increase
in shell
1ength of
of the
the two
two groups
groups was
was similar.
simi 1ar.
in
shell length
Butter Clams.
Butter
Clams. There
There is
is no
no data
data available
available on
on butter
butter clam
clam growth
growth rates
rates in
in Oregon
Oregon
to
the data
data on
on the
the clams
clams planted
planted near
near the
the breakwater.
breakwater. Growth
Growth rates
rates
to compare
compare with
with the
of butters
butters in
in these
these two
t\'IO experimental
experimental plots
plots are
are comparable
comparable to
to growth
growth rates
rates of
of
of
butter
in British
(Fraser and
butter clams
clams in
Britisn Columbia
Columbia (Fraser
and Smith,
Smith, 1928;
1928, Quayle
Quayle and
and Bourne
Bourne 1972).
1972)
From the
laboratory-reared clams
to be
From
the results
results obtained
obtained so
so far,
far, these
these laboratory-reared
clams seem
seem to
be doing
doing
well in
in field
field plots.
plots.
well
ABALONE STUDIES
STUDIES
ABALONE
METHODS
Abalone SDawnin
Spawning
Abalone
Adult abalone,
abalone, to
to be
be used
used as
as spawning
spawning stock,
stock, were
were obtained
obtained from
from three
three areas;
areas; Fort
Fort
Adult
Bragg,
California, near
near t3rookings,
Brookings, Oregon,
Cove near
near Newport,
Newport, Oregon.
Oregon.
Bragg, California,
Oregon, and
and at
at Whale
Whale Cove
Fifty
Fifty adult
adult abalone
abalone were
were collected
collected at
at Fort
Fort Bragg
Bragg in
in April
April 1973
1973 and
and successfully
successfully
transported with
with 100%
100% survival
survival to
Newport Laboratory
Labo:~atory in
in wooden
\'Iooden fish
fish boxes,
boxes.
to the
the Newport
transported
lined and
damp burlap
burlap sacks.
sacks. The
The abalone
abalone were
held in
in the
the laboratory
laboratory
lined
and covered
covered with
with damp
were held
The water
water
in blo
550-1 iter tanks
tanks at
at aa water
water temperature
temperature of
of 7-8
7-8 CCfor
for two
two months.
months. The
in
two 550-liter
was renewed
renewed every
every two
two weeks.
weeks. We
began conditioning
conditioning the
the abalone
abalone in
in June.
June. Filtered
We began
Filtered
was
and
seawater was
was run
run through
through the
the tanks
tanks at
at aa rate
rate of
of 3-5
3-5 l/min.
l/m"in. The
and sterilized
sterilized seawater
The
C).
Lights
water was
heated with
with aa water
water immersion
immersion heater
heater to
to 14
14 CC (+
(+ 11 C).
Lights in
in the
the
water
was heated
room
longest possible
possible photoperiod
photoperiod occurring
room were
were adjusted
adjusted to
to a
a period
period equaling
equaling the
the longest
occurring
during
the suniner
surrmer (5:30
- 9:00 PM).
Pf·1). Bull
kelp (Ivereacyatis
(Nereocyatis 7uetkeana)
l-uetkeana) blades
Bull kelp
blades
during the
(5:30 AN
AM were fed
fed daily
daily to
to the
the abalone.
abalone.
were
the southern
in June
Fourteen adult
Fourteen
adult red
red abalone
abalone were
were collected
collected from
from the
southern Oregon
Oregon coast
coast in
June
Abalone were
were
1973
in the
the same
same way
way as
as the
the Fort
Fort Bragg
Bragg animals.
animals. Abalone
1973 and
and conditioned
conditioned in
collected
from Whale
Whale Cove
Cove in
in September.
September.
collected from
Methods used
Attempts to
to spawn
spawn the
the abalone
abalone began
began in
in August
August 1973.
1973. 14ethods
used were
were similar
similar to
to
Attempts
In addition
addition we
used in
in previous
previous years
(Lukas 1972,
1972, 1973).
1973). In
we tried
tried electrical
electrical
those used
those
years (Lukas
Electrical current
shocking
as aa method
method to
to initiate
initiate spawning.
spawning. Electrical
current ranging
ranging from
from 55 -- 15
15
shocking as
volts
for
5
seconds
duration
were
tried.
volts for 5 seconds duration were tried.
Whale
Cove Abalone
Whale Cove
Abalone
In June
intertidal area
area of
of ihale
Hhale Cove
Cove was
was searched
searched for
for red
red abalone
abalone planted
planted
In
June 1973
1973 the
the intertidal
Sampling
was
conducted
on
days
with
low
tides
as
juvenil
es
in
r'lay
and
June
1967.
Samp
1;
ng
was
conducted
on
days
wi
th
10\-1
tides
as juveniles in May and June 1967.
Animals recovered
of -2
-2.77 and
and -2
-2.8
feet. Animals
recovered were
were measured,
measured, tagged,
tagged, and
and replaced
replaced.
of
8 feet
-19-19­
RES tiLTS
RESULTS
Abalone Soawnin
Spawning
Abalone
Spawning attempts
attempts with
the red
red abalone
abalone were
were unsuccessful,
unsuccessful, at
at least
least under
under controlled
controlled
Spawning
with the
conditions
conditions.
Part
There
was aa
Part of
of the
the problem
problem may
may be
be our
our conditioning
conditioning technique.
technique
There was
during the
the conditioning
conditioning period.
period. We
We selected
selected only
only those
those animals
animals
gain
gain in
in gonad
gonad size
size during
largest gonads
gonads for
for spawning
spawning purposes.
purposes. However,
However, since
since none
none of
of these
these
with
the largest
with the
animals
spawned they
they may
may not
not have
have had
had fully
fully developed
developed gonads.
gonads. Abalone
obtained
animals spawned
Abalone obtained
from
but did
from the
the Brookings
Brookings area
area had
had full
full gonads
gonads when
when collected
collected but
did not
not respond
respond to
to
spawning inducements.
inducements. Several
spawned in
;n the
the conditioning
conditioning tank
tank one
one week
week after
after
spawning
Several spawned
arrival
at the
the laboratory.
laboratory. The
spawning was
was at
at night
night and
and not
not induced.
induced. The
The majority
arrival at
The spawning
majority
becalJse of
the possible
possible excess
sperm in
in the
of
the larvae
larvae did
not develop
normally because
of the
did not
develop normally
of the
excess sperm
the
water.
did salvage
salvage several
several thousand
thousand viable
viable larvae
larvae and
and held
held them
them in
in 22 liter
liter beakers
beakers
We did
water. We
at
temperature of
of 14
14 CC. Some
the larvae
larvae developed
developed to
to the
the setting
at a
a water
water temperature
Some of
of the
setting stage
stage
but none
none settled
provided as
as aa food
food source,
but
settled on
on diatom~coated
diatom-coated glass
glass slides
slides provided
source, and
and
eventua
lly died.
di ed.
eventually
Whale
Whale Cove
Cove Abalone
Abalone
Eighty-eight
red abalone
abalone were
were located
located and
and tagged
tagged at
at Whale
!:Jhale Cove.
Cove. Average
length of
of
Eighty-eight red
Average length
the abalone
(range, 87-162
and average
(range
the
abalone was
was 118.5
118.5 mm
mm (range,
87-162 mm)
mm) and
average width
width was
was 84.2
84.2 mm
mm (range
60-117 mm).
60-117
mm). In
In six
these animals
animals have
have grown
grown 99.7
99.7 mm
mm in
in average
average shell
shell length.
length.
six years
years these
Of
the 88
88 abalone
abalone recovered,
recovered, 15
15 had
had been
been tagged
tagged in
in June
June 1972.
1972. Of
Of these
these 15,
15, only
only
Of the
3
still retained
3 still
retained the
the Peterson
Peterson disc
disc tag,
tag. The
The remaining
remaining 12
12 retained
retained the
the stainless
stainless
attachment
wire. Growth
these three
in one
2~ 14,
and 22
22 mm.
mm.
Growth of
of these
three in
one year
year was
was 2
14, and
attachment wire.
Si
x of
the abalone
aba lone were
were cut
cut on
on the
the foot
foot when
v/hen they
they were
were retrieved.
retri eved. The
animals
The animals
Six
of the
were
placed in
in the
the laboratory
laboratory for
for observation.
observation. The
serious cut
cut was
was approxapprox­
were placed
The most
most serious
the foot.
foot. All
injuries healed
healed in
in 22 -- 33 months
imately
imately ~-inch
½-inch into
into the
the side
side of
of the
All injuries
months with
with
no mortality.
This survival
survival after
after injury
injury is
is contrary
contrary to
to what
what many
many workers
workers have
have
no
mortality
This
stated.
stated.
OISCUSSION
DISCUSS
ION
Abalone Spawning
Spawning
Abalone
During
past three
to spawn
spavin several
several groups
red
During the
the past
three years,
years, we
we have
have attempted
attempted to
groups of
of red
abalone
and thus
thus far
far have
have been
been unsuccessful
unsuccessful. We
We do
do not
not know
know specifically
specifically why
why
abalone and
the animals
have not
not responded
responded to
to spawning
spawning inducements.
inducements. The
The methods
used have
have
the
animals have
methods used
been similar
similar to
to those
those used
used by
by other
other investigators
investigators for
for other
other species
species of
of abalone.
abalone.
been
In addition
have tried
tried innovations
innovations of
of our
our own.
own. The
and unexpected
unexpected
The occasional
occasional and
In
addition we
we have
spawnings
have occurred
laboratory have
have indicated
indicated to
to us
us that
the gonads
spawnings which
which have
occurred in
in the
the laboratory
that the
gonads
of
of the
the animals
we were
were not
not applying
applying the
the
of some
some of
animals were
were developed.
developed. Apparently
Apparently we
right inducements
be other
poor
right
inducements at
at the
the right
right time,
time, or
or there
there may
may be
other factors
factors such
such as
as poor
water quality
quality or
or water
\'Jater chemistry
chemistry which
has influenced
influenced the
the abalone.
abalone.
water
which has
j-20­
LITERATURE CITEE)
CITED LITERATURE
Fraser,
C. f4cLean,and
"lcLean,and Gertude
Fraser, C.
Gertude N.
H. Smith.
Smith. 1928.
1928.
butter clam,
clam, Saxidomus
giganteus Deshayes.
Deshayes.
butter
Saxidomiw giganteus
[~otes
the ecology
ecology of
of the
the
Notes on
on the
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Trans.
Lukas,
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1972.
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1972.
Clam-Abalone Spawning
Spawning and
Act. July
July 1,
1, 1970
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June 30,
30, 1973.
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Fish Corn.
Completion
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Clam
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1973.
Inventory
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Inventory Techniques
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The
fisheries of
of British
British Columbia.
Columbia.
The clam
clam fisheries