-------
INDEX OF RELRTIVE IMPORTHNCE (I.R.I.) DIflGRRM
FROM FILE IDENT. WW BS. STRTION flLL
PREDflTOR 8791030601 - MICROOflDUS PROXIMUS
(PflCIFIC TOMCOD ) fiOJUSTED SflMPLE SIZE = 46
lOOr
80
: so
CD
§
" 40
20
§ 20
2 4°
I—
1 60
S 80
a.
100
« r
t- i
to ra
V y-. ,-n
u. s: o a.
20
40
60
80
100 120 140 160 180 200
CUMULflTIVE FREQUENCY OF OCCURRENCE
PREY ITEM
GAHHARIDFA
CALANOIDA
PEMAEIDAE
ClIWACEA
VALVIFERA
FLARELLIFFRA
M Y^ I DAE
OSTEICHTHYES
PAGURIOAE
OECAPODA-RRACHYURA
PFRACARIDA-MICROCEPREPIDEA
FREQ NUM.
OCCUR COMP.
70.00 19
41.00 29
33.00 12
IS. 00 5
13.00 1
11.00 3
7.00
?.oo
?.oo
2.00
?.00 2
41
.PI
.94
.63
.64
.05
.94
.47
.47
.P2
COMP._
7.67
.52
f 3.74
.72
2.3?
?.89
.2?
8.12
1.11
2.31
P. 89
PREY PERCENT
I.R.I. TOTAL IRI
l?97.n 44.
1?43.S 16.
2530.4 34.
95.? 1.
5] .S ,
65.3
«. 1 .
17.? .
2.7
5.6 .
23.4
70
90
50
30
70
90
00
20
00
00
30 ~~~
PREY TA»A WITH FREO. OCCllP. LE";1; THAN 5 AND NUMERICAL ANH OOAVIMETRIC
COMPOSITION BOTH LESS THAN 1 ARE" F XCLIIDF n FOO" THE TABLE ANO PLOT
(HUT NOT FROM CALCULATION OF DIVERSITY INDITES)
PEBCENT"OnMlNANCF INDEX
SHANNON-WFINER DIVERSITY
EVENNESS INDFX
.27 .43
.2? l.BR
.64 .54
.35
1.7?
.57
Fig. B-21.
IRI prey spectrum of juvenile Pacific tomcod from shallow
sublittoral habitats along the eastern shoreline of northern
Puget Sound.
112
-------
Pacific tomcod, mainly juveniles (65%), were often caught in abundance
in both beach seine and townet collections along the Strait of Juan de Fuca.
Beckett Point, Jamestown and Point Williams, Morse Creek, and West Beach
contributed the most specimens. The overall prey spectrum (Fig. B-22) is
composed almost exclusively of epibenthic crustaceans, including gammarid
amphipods (84.3% of total IRI), mysids (4.0% , including Archaeomysis
grebnitzki), hippolytid shrimp (3.5%, including Heptacarpus brevirostris).
harpacticoid copepods, cumaceans, and unidentified shrimp.
Juvenile tomcod collected in Nisqually Reach (Fresh et al. 1979) had
fed predominantly upon epibenthic crustaceans, gammarid amphipods and
hippolytid and crangonid shrimp.
Walleye Pollock (juvenile)
Most of the juvenile walleye pollock collected in northern Puget Sound
originated from winter beach seine collections at Birch Bay and Cherry Point.
Epibenthic or benthic organisms were the principal prey organisms; gammarid
amphipods constituted 69.6 percent of the total IRI, valviferan isopods
contributed 7.8 percent, while hyperiid amphipods, shrimp, and calanoid
copepods made up lower contributions (Fig. B-23).
In the Strait of Juan de Fuca, juvenile walleye pollock occurred mainly
in fall and winter beach seine collections at Beckett Point and Dungeness
Spit and in townet collections at Jamestown and Point Williams. Calanoid
copepods, because of their numerical predominance, constituted the most
important item in the IRI prey spectrum (67.1% of the total IRI) (Fig. B-24).
Gammarid amphipods (15.8%), hippolytid shrimp (including Heptacarpus
brevirostris, 8.8%), mysids (including Archaeomysis grebnitzki, 3.1%), and
cumaceans (1.1%) were the other prey of significance.
Post-larval pollock collected in late spring in the neritic waters of
the Strait of Georgia (Barraclough 1967a-c); Barraclough and Fulton 1967,
1968; Robinson et al. 1967 a, b: Barraclough et al. 1968; Robinson 1969)
indicated that calanoid copepods and crustacean larvae were the prevalent
organisms consumed by the pelagic juveniles.
Threespine Stickleback
Threespine sticklebacks were the second most frequently encountered
neritic species in northern Puget Sound. The more important prey organ-
isms were both epibenthic—harpacticoid copepods (67.0% of the total IRI)
and polychaetes (3.7%)—and pelagic—calanoid (14.2%) and euphausiids
(13.3%) (Fig. B-25).
Threespine stickleback collected by beach seine in the southern North
Sound sites at Guemes Island and Padilla Bay had also consumed epibenthic
crustaceans; 76.4 percent of the total IRI was gammarid amphipods, 14.8 per-
cent harpacticioid copepods, 4.6 percent crab larvae and 1.3 percent cumaceans
(Fig. B-26).
113
-------
lOO
INDEX OF RELRTIVE IMPORTRNCE (I.R.I.) DlfiGRRM
FROM FILE IDENT. 76-78. STfiTION RLSTR
8791030601 - MICROOflDUS PROXIMUS
PflCIFIC TOMCOO
RDJUSTED SRMPLE SIZE r 272
CUMULflTIVE FREQUENCY OF OCCURRENCE
FDEO NUM. GPAV. PREY PEPCENT
PREY ITEM
GAMMARIDEA
"YSIDACF.A
CIJMACEA
SPHAEROMATinAE
GAUMARIDAF
HIPPOLYTIDAE
POLYCHAETA
NATANTIA
HABPHCTICOIOA
CALANOIDA
_TRf NGONlDAE
FtlOHAUSIACEA
PAsOALIDAf
OSTFICHTHYS
CLIIPEIDAE
Alll OPHVJCHinAE
OCCUR (
55.15 '
?3.53_
19.85
17.65
17. ?«
13.60
1P.13
11.76
7.15
*.62
6.62
4.04
?.9ii
1.84
.17
.17
:OMP.
56.40
6.4)
?.78
i .e.R
1.P5
1 .66
1 .44
2.17
9.78
7.95
.55
1.84
.24
.06
.01
.01
COMP.
35.79
*.09 ...
.84
1.16
1 .55
13.86
3.6?
3.14
.09
.20
5.65
1.01
13.3?
8.34
2.19
1.21
I.P.I.
^083.9
246.9
71.9
53.6
93.3
?13.H
6) .It
62.4
7?. f,
54. n
41.1
11.5
19.9
15.5
.8
. i.
TOTAL IRI
P?.84
4.02
1.17"
.87
1.5?
3.48
1.00
__... 1.02
1.18
.88
.67
.19
.65
.25
.01
.01
PREY. TAXA KITH FREQ. OCCUR. LESS THAN 5 AND NUMERICAL AMI GRAVIMETRIC
COMPOSITION POTM LESS THAN 1 APE EXCLUDED FPOM THF TAPLE AND PLOT
(RuT NOT FPOM CAI CULATION OF DIVERSITY INDITES)
Fig. B-22.
PEPCENT DOMINANCE INDEX
SHANNON-WMNEP DIVERSITY
.EVENNESS INDEX . . ....
.34
2.50
.47
.18
3.?0
.60
.69
1.24
.23
IRI prey spectrum of juvenile Pacific tomcod in the Strait of
Juan de Fuca.
114
-------
CD
s
g
fe
s
INDEX OF RELRTIVE IMPORTRNCE (I.R.I.) DIRORRM
FROM FILE IDENT. WW BS. STflTION flLL
PREOflTOR 8791030701 - THERRGRR CHflLCOORRMHfi
(HRLLEYE POLLOCK ) ROJUSTEO SRHPLE SIZE * 20
100
80
60
40
20
2 20
i 40
I—
I 60
^ 30
u
100
20
40
60
80
100
120
140
CUdULflTIVE FREQUENCY OF OCCURRENCE
P°EY ITEM
FREQ
OCCUR
NUM.
COMP.
GPAV
COMP
PREY
. I.P.I. _
PERCENT
TOTAL IRI
VALVIFEPA
AMPHIPOOA-HYPERIIDFA
CA|
CRUSTACEA
.POLYCHAETA _
EUPMAUSIACEA
FL'BELLIFERA
?n.no 7.94
10.00 __ 3.18
in.00 11.90
^.00 .79
5.00 _ .79
^.00 1.59
5.00 2.38
10.95 ]084~.7
13.93
3.98
17.91
.00
1.00
3.48
171.1
158.8
93.5
. *.0_
12.9
98.9
A9.90
17.80
3.40
?.80
?.60
1.50
.00
.20
1 .60
POFY TAXA WITH FREQ. OCCUR. LF^^ THSN 5 AND NUMEOICAL ANfl HP4VIMETRIC
COMPOSITION BOTH LESS THAN 1 ARE EXCLnnEH FonM THF TAPLF ANin PLOT
i"T FBOM_CA| CUL4 T ION OF
PERCENT DOMINANCE INDEX
SH4NNON-WFINER DIVERSITY
EVENNESS INDEl
.28 .28
2.20 2.26
.70 .75
.52
1.46
.49
Fig. B-23. IRI prey spectrum of juvenile walleye pollock in shallow sub-
littoral habitats along the eastern shore of northern Puget Sound.
115
-------
>-
CO
s
5
§
CJ
I—
o
lOOr
INDEX OF RELRTIVE IMPORTRNCE (I.R.I.) DIRCRRM
FROM FILE IDENT. 76-78. STRTION RLSTR
8791030701 - THERRORR CHRLCOORRMMR
WRLLEYE POLLOCK
RDJUSTED SRMPLE SIZE = 74
200
250
PPFv ITEM
CUMULRTIVE FREQUENCY OF OCCURRENCE
NUM
FREO
OCCUR
GRAV.
COMP.
P9EY
I.B.I.
PERCENT
TOTAL IRI
GAMUARIDAE
CALAN01DA
GAMM4P10E*
CilMACEA
. MY.<;IDACFA _____ ___
__ 31.08 _79
21 .*>?
NATANTIA
EIIPHAUSIACEA ______
OSTPACOOA
HAPPACTICOIDA
-ElJCAPIDA-DECAPODA-SpAChYRIYNCH
PSC'OALIDAE
POLYCHAFTA
.
CRANGONIOAE
14.8ft
13.SI
10.81
8.11
6.76.
S.4]
?!70
58
71
b2
82
82
90
49
77
20
38
15
20
15
05
0?
8.92
21.07
6.61
1.57
_ 5.75
P6.84
1.90
3.48
.26
.08
. 15
10.70
1.30
7.24
1 .35
388.6
3132. 3 _
348.1
51 .*.
- 143.? .
412.3
32.3
- 45.9
3.7
9.9
a.o-
S8.9
7.9
_. 19.7
1.9
8.32
67.06
7.47
1 .10
-3.07
8.83
.69
-- .98
.08
.21
,04
1.26
.17
.4?
.04
RRFY TAxA_nITM FDfQ. OCCUR. LF^S_THAM «i AND NUMERICAL AND G" A V I METR I C_
COMPOSITION HOTH LESS THAN 1 ABE EXCLUDED FROM THE TABLE AND PLOT
(BUT NOT FRO" CALCULATION OF DIVERSITY INDICES)
PERCENT DOMINANCE INDEX
SHANNON-WEINE" DIVERSITY
EVENNESS INDE«
.6^ .15
1.31 3.22
.27 .67
.47
1.81
.38
Fig. B-24. IRI prey spectrum of juvenile walleye pollock in Strait of Juan
de Fuca.
116
-------
Along the Strait of Juan de Fuca, adult threespine stickleback
were most common in Beckett Point, Jamestown, and Point Williams beach
seine collections. Unlike northern Puget Sound, it was not often
encountered in the townet collections. Threespine stickleback appeared
to be feeding throughout the nearshore water column, as pelagic calanoid
copepods and epibenthic harpacticoid copepods were qually important (Fig.
B-27). Limited sample sizes, however, do not allow us to determine whether
this catholic feeding beahvior is due to diel changes, site differences or
collection methods. Secondary prey organisms were mostly epibenthic forms,
including gammarid amphipods and mysids.
Bay Pipefish
Several adult bay pipefish from beach seine collections at Birch
Bay were large enough to permit analysis of their stomach contents; 86.8
percent of the total IRI were isopods, the remainder, gammarid amphipods.
Tube-snout
Tube-snouts were frequently captured in the mud/eelgrass and sand/
eelgrass habitats and pocket gravel beaches in northern Puget Sound. Common
identifiable organisms included gammarid amphipods (90.0 percent of total
IRI); only polychaete annelids (6.3 percent), and crab larvae (1.8 percent)
were secondary prey. Tube-snouts from beach seine collections along the
eastern shoreline, Birch Bay and northeast Guemes Island, tended to have more
pelagic organisms in their diet. Pelagic calanoid copepods composed 73.5
percent of the total IRI, while harpacticioid copepods (32.1 percent), gammarid
amphipods (23.9 percent), and mysids (7.6 percent) made up the principal
epibenthic prey composition.
Along the Strait of Juan de Fuca, beach seine and townet collections
at Beckett Point and Morse Creek produced numerous tube-snouts. As in the
case of threespine stickleback, both calanoid and harpacticoid copepods were
the principal prey species of tube-snouts feeding in nearshore habitats
(Fig. B-28) . Shrimp larvae, though constituting 28.9% of the total prey
biomass, were not abundant prey items.
Tube-snout from the Nereocystis kelp beds at Barkley Sound examined
by Leaman (1976) had consumed primarily barnacle larvae and caridean
crustaceans.
Kelp Greenling
Kelp greenling were the most commonly observed fish in the rocky/
kelp bed habitats of northern Puget Sound and often characterized the protected
gravel beach enviornments such as those at Deadman Bay and Legoe Bay The
prey spectrum for kelp greenling (Fig. B-29) was one of the most diversified
so rank^T d°C™ented- *npMpods, principally Eusiroides sp., Amphithoides
sp., ranked as the most important (46.1 percent of total IRI) prey, followed -
by crabs, Cancer magister, Pugettia ^racilis , Oregonia gracilis Telmessus
chexra. and unidentified -
117
-------
INDEX OF RELRTIVE IMPORTflNCE (I.R.I.) DIHGRflM
FROM FILE IDENT. N POSD. STHTION flLSTfl
PREDftTOR 8818010101
(THREESPINE STICKLEBK)
CflSTEROSTEUS flCULEflTUS
RDJUSTED SflMPLE SIZE 14
m
g
8
Q_
100
80
60
40
20
- 20
40
° 60
§
(_>
i-l 30
100
I 3 C
20
40
60
80
100
120
140
160
180
CUMULflTIVE FREQUENCY OF OCCURRENCE
PREY ITFM
OCCUR
NUM.
COMP.
CPAV.
COMP.
PREY
I.R.I.
PERCENT
TOTAL IRI
-HAopACTlcoirrA
POLYCHAFTA
CORF.PODA
CALANOI'lA
FUPHAUMACEA
AMRHIPonA-rlYPEWI IDEA
LARVACFA
FLARFLLIFFRA
~~ 50.00
43.00
14.00
14.00
14.71(1
7.00
~~ ~~ 7. on
7.00
7.00~~
7.00
ACFA 7.00""
55.97
.65
33.77-
.47
" .19
.65
.47'
1 .03
.09 -
.09
2.15
.00 ?798.S
2.90
P. 17- '
.00
.00
7H.84
.-.1"
.41
.00
4. 15
.4]
152.6
594.7 —
6.6
2.7
556.4
6.2
10.1
.6
29.7
17.Q
67.00
3.70
14.20
.20
.10
13.30
.10
.20
.00
.70
.40'
PPFY TMXA WITH FDFO. nccMB. irc.s. THAN'S AND NUMERICAL" ANT GRAVIMETRIC
cn>'pn<;iT ln\ POTH L^S THAN i AOE FKCLHPF.O FROM THE TABLE AND PLOT
(R'lT NOT FRO" CA| CUL'TION OF nivFR^TTY
PF5CENT DOMUJANCF INOFX "
SHAN'JON-WF INf P RIVE>"^ITY
INPtt
— .43
1.19
.40
1.00
1 .49
.45
Fig. B-25. IRI prey spectrum of threespine stickleback from northern Puget
Sound.
118
-------
s
to
g
I—
§
fc
s
INDEX OF RELflTIVE IMPORTflNCE (I.R.I.) DIflORRM
FROM FILE IDENT. WW BS. STflTION flLL
PREDflTOR 8818010101 - GflSTEROSTEUS flCULEflTUS
(THREESPINE STICKLEBK) RDJUSTED SRMPLE SIZE 15
100
80
60
40
20
§ 20
40
60
80
100
PREY ITEM
20
40
60
80
100 120 140 160 180 200
CUMULflTIVE FREQUENCY OF OCCURRENCE
FREQ
OCCUR
NU".
CO«P.
GRAV.
COMP.
PREY
I.R.I.
PERCENT
TOTAL IRI
_ __
" HiBPACTICOIDA
OEC»POD»-BPACHYU"A
CU-ATEA ____
OLIGOCHAETA
CPL'STACFA
CIRRIPEDIA
LARVACEA
33.00
27.00
27.no
n.no
7.00
7.00
7/00
7.no
27.74
"34.35
4.84
.48
14.6«
.16
.16
.65
1.75
8.77
1.75
7.02
.88
.00
3.51
.00
6)49.3
1191.3
167.5
108.3
97.^5
108.9
_ 1.1
?5.7
76.40
14.80"
4.60
1.30
1.20
1.40
.00
.30~
.10
PRFY TA«A 1.ITH FPEQ. OCCllH. L^S^ THAN 5 AND NUMERICAL ANn GOAVIMETRIC
COMPOSITION OQTH LESS THAN 1 ARE EXCLUDED FROM THE TARLF ANO PLOT
_[B|lJ_NOT_FHnu_CALCULAT^ON OF DIVERSITY INDICES)
PERCENT DOMINANCE INDEX
SHANN"N-WI\FO DIVERSITY
EVENNESS INOFi
.22
1 .90
.60
.42
1.42
.51
.61
1.19
.40
Fig. B-26. IRI prey spectrum of threespine stickleback from shallow sub-
littoral habitats along the eastern shoreline of northern Puget
Sound.
119
-------
o
o
-------
fc
100
80
60
40
20
20
40
60
80
100
INDEX OF RELHTIVE IttPORTflNCE (I.R.I.) DlflORflM
FROM FILE IDENT. 76-78. STfiTION flLSTfl
8818020101 - flULORHYNCHUS FLflVIOUS
TUBE-SNOUT
flOJUSTED SflMPLE SIZE 82
20
40
60
80
100
120
OMILRTIVE FREQUENCY OF OCCURRENCE
PREY
ITEM
FPFO
OCCUR
NUM.
COMP.
GRAV.
COMP.
PREY
I.O.I.
PERCENT
TOTAL IRI
3S.37 4?. 7R
34.15 28.59
in. 98 ?.34
o.76 8.RS
7.3? - _ .8?
30.9?
6.11
8.64
?8.89
3.47
9.73
7.84
2.98
7606.5
1184.1. _
120.5
368.?
31 .-5
81.9
— . 4.1 —
58.53
26.60
2.7)
8.27
-7]
1.09
1 .84
- .09 _
CALANOIDA
HAPPACTICOIOA
MATANTIA
GAMMARIOEA
OSTFJCHTHYS
I APVACEA
-H1PPOLYTIDAE -
ODFY TAXA uITH FPEO. OCCUR. LESS THAN S ANO NIJHERICA| AND GRAVIMETRIC
CO.MPHSITIIN POTH LESS THAN i_ ARE EXCLUDED FDOM THE TABLE *ND_OLO.I
(BUT NOT FPQM CALCULATION OF DIVERSITY INDICES)
PERCENT QQMINANCE .INDEX
SHANNON-wFlMfp DIVERSITY
.29 .21
.ll ?.65
.SS .70
.42
1 .65
.43
Fig. B-28. IRI prey spectrum of tube-snout in Strait of Juan de Fuca.
121
-------
INDEX OF RELflTIVE IMPORTflNCE (I.R.I.) OlfiGRRM
FROT1 FILE IDENT. N PGSD. STHTION BLSTfl
PREOflTOR 8827010101 - HEXflGRHtlMOS OECflGRflftflUS
(KELP GREENLINC ) RDJUSTED SflMPLE SIZE 31
100
80
60
40
20
1 20
40
60
80
100
£
a. e f. —
o x u -*
u •£ H ^
3 1 SC
•o a
•O M -O X — u u
O -Q -4 p^ k. O U
o. o i- o 3 -< n
u
7
2
6
n
33.
4.
1.
S.
.
3.
.
B
.
1.
90
40
80
no
00
20
80
30
00
40
10
30
80
9n
60
10
10
00
10
70
• JO
GRAVIMETRIC
Ann PLOT
2.
01
Fig. B-29. IRI prey spectrum of kelp greenling in northern Puget Sound.
122
-------
isopods (34 percent) fishes (1.9 percent), polychaetes (3.7 percent),
gastropods (3.5 percent), and tanaids (1.2 percent). Although algae
(Rhodophyta 33.9 percent), constituted a measurable percentage of the total
biomass, these were considered incidental items, byproducts of the feeding
of kelp greenling on the predominantly benthic prey items.
The only food data for kelp greenling in the Strait of Juan de Fuca,
that from Leaman's (1976) collections at Barkley Sound, Vancouver Island,
indicated that caprellid (Caprella gracilion, £. laeviscula, C^. ferrea, C_.
incisa, and £. equilibra) and gammarid amphipods (Parapleustes pugettensis,
Erichtonius brasiliensis. Photis sp., Podocerus sp., Metaphoxis sp.) were the
most important prey; fish (Artedius lateralis. Synchirus gilli), crabs
(Pachycheles sp., Cancer gracilis, C. oregonensis, Pagurus sp. , Oregonia
gracilis, Loxorhynchus crispatus, Petrolistes eriomerus) and shrimp
(Heptacarpus sp.) were of secondary importance. The diet of greenling between
101-200 mm in length was dominated by isopods while that between 201-700 mm
was prevalently crabs.
Juvenile kelp greenling were reported by Barraclough and his co-workers
to be one of the most common fishes in the neritic waters of the Strait of
Georgia in May-June (Barraclough 1967 a, b, & c; Robinson et al. 1968 a & b).
Calanoid copepods (Calanus plumchrus, Pseudocalanus minutus), cladocerans
(Podon sp.) hyperiid amphipods (Parathemisto pacifica) and larval fish
(eulachon) were important prey taxa at this stage (Table B-3).
Whitespotted Greenling
In northern Puget Sound adult whitespotted greenling was collected most
often at pocket gravel beaches such as at Deadman Bay during beach seining.
It was also collected in the rocky/kelp bed habitat, but in much smaller
numbers than the kelp greenling.
The prey spectrum of the whitespotted greenling was very similar to the
kelp greenling (Fig. B-30). Gammarid amphipods, especially Eusiroides sp.,
Amphithoe sp., constituted the most important food item, contributing 55.7
percent of the total IRI. Shrimp (Heptacarpus stimpsoni), with 22.4 percent,
and various brachyuran crabs (Cancer oregonensis, Pugettia gracilis), with
11.4 percent of the total IRI, were secondary; fish and polychaete annelids
provided less than 5 percent each. Incidental algae, however, was not as
significant in the overall diet composition ofthe whitespotted greenling as
the kelp greenling. Whitespotted greenling were often collected during
beach seine sampling at northeastern Guemes Island, Birch Bay, Cherry Point
and Legoe Bay along the eastern shoreline. Despite the different areas and
habitats, prey composition of this sample was very similar to those from San
Juan Island collections, with gammarid amphipods responsible for 65.9 percent
of the total IRI; penaeid and callianassid shrimp, 21.6 percent; brachyuran
crabs, 10.0 percent, and polychaetes, 1.3 percent (Fig. B-31).
Along the Strait of Juan de Fuca, whitespotted greenling, most of which
were juveniles, were included in beach seine collections at Beckett
Point and Point Williams. The overall prey spectrum of whitespotted greenling
123
-------
Table B-3. Prey composition table for juvenile kelp greenling in neritic
waters of Strait of Georgia, documented by Barraclough (1967a)
PREDATOR ^8927010101 - HEXAGRAMMOS DECAOPAMMUS (KELP GREENLING
INDEX OF~RELATIVE IMPORTANCE (I.P.I.) TABLE
FROM FILE IDENT. REF 1, STATION ALSTA
FREO "" NUM. GRAV. PPEY PERCE
PREY ITEM OCCUR COMP. COMP. I.R.I. TOTAL
:NT
IRI
-CALANOIDA ---- -------------- 98.90 97.50
AMPHIPQDA S.40 1.00
"OSTEICHTHYES --------- -------- 3.30 ---- .'30
EUPHAUSIACEA ?.20 .10
"CRUSTACEA ~ -------- ?.?0 1.00
THERAGRA CHALCOGRAMMA 1.10 .10
~OIKOPLEURA^SP. 1 .10 MO
WTTH^FREO.~~OCCuRT~LE:<;s"THAN S "ANO~NUMERICAL
COMPOSITION ROTH LESS THAN 1 ARE EXCLUDED FPQM THE TABLE AND PLOT
-------
INDEX OF RELRTIVE IMPORTRNCE M.R.I.) DIRCRfitl
FROM FILE IDENT. N PGSO. STRTION RLSTfi
PREDRTOR 8827010104 - HEXflGRRdMOS STELLERI
(HHITESPOT GREENLING 1 HOJUSTED SflflPLE SIZE = 13
100
B
1 80
! 60
m
•z.
o
~ 40
8
8:
8 2°
t—
<_>
o> „
0
I
COMPOSITION BY HEIO
8 £ S
>- 80
inn
1 —
mi—
1 «
I
ti
t « 0
S 5 .
S £• 6
V % S
« a 4 i- . W « « J=
« <• q £ X •-> 1 C.
•v -a e *j£«*«
•H 5 4i ,C G. * T3 O
^ a- & ^£-5S.5
E £ O «IOX«h>
E & » Wf-i^tuo
0 5 2 OUbOU
Trf B^
P
Lr
0)
•
V
k. a
>. • -b u x-r* w w
acectnoniwoc u «
SO 100 ISO ZOO 250
CUMULflTIVE FREQUENCY OF OCCURRENCE
300
350
PRCT ITEM
~Gl»M»RIntA~
*HPH1POO<
PLtOCYFM»T»-CAR10E»
pf-D«c«Pln»-SPEL»fO&P»P>-»CE*
O^TFICnrMYt5
CHI.OnOPMTT*
POLTCKAET* "~
OEC»nOD»-BP*CHYljB«
OMnP|MOSPM«EPOM« OBEOONENSIS
PH«frPHYt»
o«r>"PlD*E
P»Kn«LI04E
MY<;IO»CE«
p"COnpMYT»
rL«1F.LLIFE»»
OE<»«P.EStI»CE»E
MOOD
PEK»EID»E
DEOPnO*
V«LVIFEP».
FBEQ
OCCUS
3M.OO
3A.OO
38.00
31.00
31.00
33.00
Z3.00
15.00
15.00
e.oo
A. 00
x.no
B.OO
ft. 00
A. 00
e.oo
8.00
8.00
A. 00
«.oo
NUM.
COMP.
27.91
11.63
<..65
16.7*
3.3*
3.72
2.79
?0.93
2.3)
.93
.93
.'7
.47
.*7
.47
.*7
.47
1.40
.47
.47
GP*V.
COMP.
1 T74 "
5.67
16.54
8.04
4.69
1.26
6.26
1.42
.23
.07
22.46
16.37
.00
.03
.00
.10
.04
7.8*
1.20
1.01
PREY
I.R.I.
"f 126.7 ~
657.4
805.2
768.2
372.9
114. s
208.1
315.2
38.4
8.0
187.1
134.7
3.8
4.0
3.8
4.6
4.1
74.)
13.4
11.4
PERCENT
TOTAL IRI
T3~.10
13.50
16.50
15*80
7.60
2.30
4.30
6.90
.80
.00
3.80
2.80
.00
.00
.00
.00
.00
1.50
".30
.20
PBFY TAXA yITM rpfQ. OCCljK. LESS THAN 5 AND NUMERICAL AND GRAVIMETRIC
COMPOSITION BOTH LESS THAN 1 ARE EnCLUOEO FPOM THE TABLE AND PLOT
<«IUT NOT FRO" CALCULATION OF DIVERSITY INDICES!
PEoCENT Or-lNtNCE IMCEX
S^iv.^'J-wF I M P DIVERSITY
.17
3.0'
.71
.13
3.19
.7'
.14
3-11
Fig. B-30. IRI prey spectrum of whitespotted greenling in northern Puget
Sound.
125
-------
INDEX OF RELflTIVE IMPORTANCE (I.R.I.) DlflGRflfl
FROM FILE IOENT. WH BS. STflTION RLL
PREDRTOR 8827010104 HEXflGRflMMOS STELLERI
(HHITESPOT GREENLINO ) flDJUSTED SflMPLE SIZE = 13
100
80
: eo
oa
o
£ 40
if
S 20
2 20
£
>-
(O
z 40
g 60
80
100
20
40
60
80
100 120 140 160 180 200
PREY ITEM
CUMULRTIVE FREQUENCY OF OCCURRENCE
FREO NUM. GRAV. PREY PERCENT
OCCUR COMP. COUP. I.P.I. TOTAL IRI
_GAMMARir>FA^ 6P.no 75.70
PENAE'IOAE 38.00 6.21
EUCARIDA-OECAPDDA-RRAC^YRHYNCH 23.00 3.95
OECAPODA-BRACHYI)RA_ 15.00 1.13
POLYCHAETA " 15.00 1.69
TANAIOACEA 8.00 2.82
DECAPOOA-BRACHYUPA «.00 2.26
EUPHAUSIACEA ~ fl.OO .56
VALVIFERA S.OO .56
_TARDIGRADA 8.00 _ .56
PERACARIOA-MICROCERBERIDEA B.no .56
PLEOCYEMATA-CAPIDEA «.oo .56
CALL1ANASSIOAF 8.00 .56
16.83
23.12
15.60
P. 83
3.69
.22
6.26
.35
1.10
.06
?.20
1 .69
15.97
3B02.'
1116.5
669.6
59.6
77.7
26.3
6B.O
7.3
13.3
5.0
22.1
Ifl.n
132.?
65.90
19.30
7.80
1 .00
1.30
.60
1.20
.10"
.20
.00
" .60
•30
2.30
PRFY TAXA WITH FREO. OCCUR. LESS THAN 5 AND NUMERICAL AND GRAVIMETRIC
_ COMPOSITION ROTH LESS THAN 1 ARE EXCLUDED FROH_THE TARLE ANH PLOT
(HUT NOT FROM CALCULATION OF~DIVFRSITY INDICES)" " ~
PERCENT DOMINANCE INDEX
SHANNON-HEINEP DIVERSITY
EVENNESS INDEX
.58 .13
1.63 2.65
.39 .72
.60
1 .61
.65
Fig. B-31. IRI spectrum of whitespotted greenling in shallow sublittoral
habitats along the eastern shoreline in northern Puget Sound.
126
-------
was one of the most diverse encountered. Gammarid amphipods were the most
important prey (60.9% of total IRI) but tanaids, polychaete annelids,
hippolytid shrimp (Heptacarpus sp.), crangonid shrimp, bivalves and bivalve
siphons, and majid and pagurid crabs all composed more than 1% of the total
IRI (Fig. B-32).
Lingcod
The lingcod was commonly observed in rocky/kelp bed habitats of northern
Puget Sound (57 percent frequency of occurrence during SCUBA transect
observations) and consituted the major top-level carnivore in the fish assemblage
characterizing that habitat. Stomach contents examined from eight adults and
six juveniles indicated that lingcod were primarily piscivorous, with 36.1
percent of the total IRI being fish. Although the fish were usually digested
beyond recognition, rockfish (Scorpaenidae) were identified. The remaining
secondary food items were benthic gastropods, siphonophores, ascidians,
polychaetes, and incidental algae. Except for the fish, which may or may not
be bottom-oriented, all the prey items were benthic.
Lingcod sampled during Quast's (1968) detailed examination of southern
California's kelp bed fish communities had consumed predominantly fishes
(Perciformes, Clupeiformes) while algae and cephalopods were less representative
prey (Table B-4) .
Copper Rockfish
Copper rockfish were commonly caught in beach seine collections in
northern Puget Sound during July and August at Deadman Bay (gravel habitat)
and were frequently sighted along all SCUBA transects in the rocky/kelp bed
habitat.
The composite prey spectrum (Fig. B-33) suggests that copper rockfish
were facultative epibenthic feeders, having consumed both benthic and pelagic
organisms. General percaridan crustaceans were the more important prey;
these included gammarid amphipods (40.3 percent of total IRI), mysids (6.0
percent), shrimp (3.0 percent) brachyuran crabs (Cancer gracilis, Petrolistes
eriomerus and Scyra acutifrons, 1.9 percent), flabelliferan (4.9 percent)
isopods, and cumaceans (1.4 percent). Fish (Pacific sand lance and juvenile
rockfish) accounted for 17.6 percent of the total IRI.
Juvenile copper rockfish sampled by beach seine along the eastern shore-
line (Legoe Bay) had a relatively similar diet composition based on epibenthic
and pelagic prey. Shrimp (Crangonidae, Pandalidae, and Penaeidae) and gammarid
amphipods predominated, with 36.1 oercent and 31.8 percent, respectively, of
the total IRI. crab larvae (15.9 percent) and fish (threespine stickleback,
J--J-/ percent) formed secondary diet components.
to
127
-------
Table B-4. Prey composition (frequency of occurrence) of lingcod in southern
California kelp beds documented by Quast (1968).
PREDATOR «p?7nin?ni - O°HIODON KLONGATUS
(LINGCOD
innF.x OF RELATIVE IMPORTANCE (I.P.I.) TABLE
FILE IPFNT. REF 59. STATION SLSTA
PRF.Y ITEM
FPFO NUM. GRAV.
OCCUR COMP. COMP.
PREY
I.R. I
PERCENT
TOTAL IRI
TELt'OSTEI
UNin^NTIFI
THEUTHIDIDA
ALG4F
1?."0
11.00
TAXA WITH FPFO. OCCtlK. LPSS ThAN S AND NUMERICAL ANO GRAVIMETRIC
COMPOSITION «OTH LESS THAN 1 ARF FxCLUDFH FROM THF. TARLE ANO PLOT
(RUT MOT FROM CALCULATION OF DIVERSITY INDICES)
PERCENT DOMINANCF INDEX
SH4NMON-WFINFC DIVERSITY
EVFNNESS
.00
.00
.00
.00
.00
.00
.00
.00
.00
128
-------
INDEX OF RELHTIVE IMPORTHNCE (I.R.I.) DIBORRfl
FROM FILE IDENT. 76-78. STHTION RLSTfl
8827010104 - HEXflORHnnOS STELLER1
HHITESPOT OREENLINO
PCT. COMPOSITION BY WEIGHT PCT. COMPOSITION BY RBUNDHNCE
SssftS^KSSSS
flDJUSTED SfltIP
«
• N « -5 «
u u n ArFA ?B.'6 11.32 .17 1?4-7 8.03
GAMMAPinAE 26.09 l?.9fl .33 347.0 8.58
HIP°nLYTlD»E 23.91 2.91 6.09 215.6 5.33
PHI YCHAFTA 10.57 4.81 9.81 »»*-«. 7. no
PtvALVIA 19.57 2.93 1.86 93.7 2.32
tPANKONlDAE 17.19 2.04 7.19 160.5 3.97
NATANTIA 15.?? 1.65 2.34 60. 0 1 .5(1
PAf-IIPIOAE 15.?? .89 |
GASTROPODA 13.04 .76
UNIOFNTIFIEr) 11.04 8.5? 1
.87 42.0 1.04
.25 13.3 .33
.94 136. S 3.38
DErAPnOA-HPACHYIlPA *.52 .39 2.94 21.7 .54
"AjTOAE 6.52 1.02 11.16 79.4 1.96
<-ADOFILIIJFA 6.s? |.27 .13 9.1 .23
FlirAP|r>A-r>S.CAPr>OA 4.15 1.15
CPI STACFA 4. 115 ?-f,7
_£.A.ir>aLinAr ,.17 _,s <;
.66 7.9 .19
.58 14.1 .35
.84 ?I.O .54
ATFLFCYCLIOAE ?,17 .25 15.06 33.1 .82
tA-^rptrjAF ?-17 -13 1-n 2>7 .07
-nSlEiCHTH^S ^,7 .13 1.58 3.7 .09
"Tim»E z.,7 .3, 3.,H ?;; .;,
EMPioTocinir ,-l7 >n ,6>,6 3T>, _,z
»;01r_LlEA£ ?,17 ,11 1.9? 4.s .11
"5Ir>T?¥I "'TH F"E0' nCC|ls- LES?^5127:' LE-iS^ LI»N_ L_ »Be._F.»ci.nneri F^OM THE TARLE AND BLOT
iSin NOT Ffco« CALCULATION OF OIvE»SITY INDICES)
EV-NNES5 ,ND,., ^^ 3;^ Z.«
' .
Fig. B-32. IRI p^y spectrum of whitespotted greenling in shallow
sublittoral habxtats along Strait of Juan de Fuca.
129
-------
1NOEX OF RELflTIVE IMPORTANCE tI.R.I.] DIRGRflM
FROM FILE IDENT. N PCSO. SlflTION RLSTfl
PREDRTOR 8826010108 SEBflSTES CRURINUS
(COPPER ROCKFISH ] RDJUSTED SRMPLE SIZE 52
100
g 80
I 6°
§
~ 40
tn
3 20
°~ 0
I—
I 20
>-
m
1 4°
1 60
^ 80
a.
100
>i i-
J= OJ "O U •-
•o •.- moiiootrc
. ,
CE QU^Ci
nj 3 (_> o a. a.
50 100 ISO 200
CUMULRTIVE FREQUENCY OF OCCURRENCE
Y.—PPEY
P»ET ITEM
-FUEO NU"~
OCCUR COWP. COMP. I.R.I. TOTAL 1RI
PtBCtNT
250
PEPACARIDA-SPELAEOGRAPHACEA
DFCABOOA-flRACHVlIRA
PAK'DALinAF
CAPRFLLIDFA
BOLYCHAFTA
fiACTPOPOOA
- CA^FW ')P»C1LIK
<;CroPAFN|OAE
AMTMIIOIOAF
PETRnl.ISTHKS EBIOMFRUS
COMOOSITIOM ROTH LE5? THAN 1
TB1IT NOT FROM CALCULATION tlF~
5HAMNOij-wF"ii'r'E°NOI«£BMTY
EVt'JNLSS INUtY
31.00 17.
31.00 9 .
30.00 3.
lh.no ID.
l?.oo
l?.no 3.
10.00
in. no
lo.no
8.00
6.00 3.
A. no
4. no
3.00 1.
3.00 .
?.nn
:F«;«-rHnfr-5-
AUC FKCLllDE
"TJIVEB^ITY^
3.
•
74 2.~45 ~14
45 3.49 6
73 .51 3
41 34.00 5
SO .46 1
89 1.58
S4 4.04
8» 5.55
76 4.30
63 .0*
51 15.01 1
OS 1.44
38 .45
51 16!ll
S3 .11
1"< 5.17
35 3.38
13 3.34
ANTT-NDMEBICAL
0 FOQM THE TA
NUICtS)
16 . !«•
88 3.30
6S . fS
49.1
IS.n
39. f.
91. n
64.1
49. >,
7.1
ll.o
?4.3
43.9
16.4
9.7
66.^
13.5
3.3
10. «.
5.1
6~.9
Aijrr
1LE «
40.30
18.10
6.00
15.30
4.90
.80
3. SO
1.80
1.40
.30
.30
3.50
i.ao
.50
.30
1.90
.40
.10
.30
.10
."
(,OAVIMtTBlC
i«jn PLOT
3.77
.63
Fig. B-33. Spectrum of copper rockfish from northern Puget Sound.
130
-------
Prince and Gotshaul (1978) documented the prey spectrum of 241
copper rockfish captured around an artificial reef in South Humbolt Bay,
California. In terms of frequency of occurrence and percent volume, juvenile
Cancer magister dominated the diet (40% of total IRI) while gammarid amphipods
composed 31% of the total number of prey items. Crangonid shrimp, caprellid
amphipods and northern anchovy provided secondary food items.
Puget Sound Rockfish
Puget Sound rockfish were documented only during SCUBA transect
observations in the rocky/kelp bed habitats along San Juan channel (Pt. George,
Shaw Is.)- The overall prey composition indicated a relatively unspecialized
planktonic feeding behavior. Calanoid copepods (57.3 percent of total IRI),
siphonophores (17.8 percent), and crab larvae (16.0 percent) constituted the
more important prey; hyperiid amphipods (5.1 percent), and crabs (1.6 percent)
were secondary in importance.
Yellowtail Rockfish
Although juvenile yellowtail rockfish were often caught in the beach
seine sampling at Deadman Bay in northern Puget Sound, the majority originated
from rocky/kelp bed habitats around San Juan Island and Burrows Island.
Prey composition, similar to those of Puget Sound rockfish, emphasized
pelagic organisms. Calanoid copepods accounted for the highest proportion
(34.4 percent) of the total IRI while mysids (20.1 percent, Neomysis
awatchensis)*, fishes (17.5 percent including Pacific sand lance), crab
larvae (10.6 percent), chaetognaths (8.4 percent), hyperiid amphipods (2.1
percent), and fish larvae (1.2 percent) composed the other food items.
Gammarid amphipods (including Pontogeneia sp., and Eusiroides sp., Atylus sp. ,
Ischyrocerus sp., and Photis californicus) were not very important.
Black Rockfish
Adult black rockfish constituted over 15 percent of the total fish
enumerated along the SCUBA transects in northern Puget Sound. Prey organisms
were predominantly pelagic organisms. Hyperiid amphipods (79.9 percent of
total IRI) were most important, followed by fishes (13.9 percent; including
Pacific sand lance and tadpole sculpins), crab larvae (1.1 percent), and crabs
(1.0 percent; Cancer sp.). Incidental items such as rocks accounted for 1.7
percent of the total IRI. Gammarid amphipods (predominantly Eusiroides sp.,
Pontogeneia spp., and Atylus sp., but also Ischyrocerus sp., Hyale sp.,
Paraphoxus spinosa (?), Photis californica, Photis sp., Amphithoe lacertosa,
and Amphithoe sp.) were not significant in the total IRI.
Juvenile black rockfish from shallow sublittoral gravel habitats at
Deadman Bay and Guemes Island had an entirely different diet composition which
emphasized epibenthic prey such as shrimp, harpacticoid copepods, and gammarid
amphipods. 6
*
Holmquist (1973) suggests that N. awatchensis should be considered as N.
mercedis m the Northeast Pacific. We have, however, left it as N. awatchenlis
to minimize confusion. —
131
-------
Scalyhead Sculpin
Scalyhead sculpins were the second most common cottid observed in the
rocky/kelp bed SCUBA observations in the vicinity of San Juan Island. The
few specimens which were procured by slurp gun or spearing indicated a
diverse array of organisms—pelagic, epibenthic, and benthic—were included
in its diet. Harpacticoid copepods were the most important prey. Chaeto-
gnaths (pelagic arrow worms), calanoid copepods, crabs (Petrolisthes
eriomerus), crab larvae, mysids, shrimps, gammarid and hyperiid amphipods,
fishes, euphausiids, and caprellid amphipods were of secondary importance.
Caprellid amphipods (Caprella mendax, £. laeviscula, C^. equilibra,
£. natalensis, £. incisa, ^. guacilior, C. ferrez, Metacaprella kennerlyi)
and tammarid amphipods (Photis californica, P_. bifurcata, Parapleustes
pugettensis, Podocerus sp., Erichtonius brasiliensis, Lembos sp.) and shrimp
(Heptacarpus sp.) were listed as prey of scalyhead sculpins collected in
Nereocystis kelp beds on the outer coast of Vancouver Island (Leaman 1976).
Smoothhead Sculpin
Smoothhead sculpins were not common in beach seine collections in either
northern Puget Sound or along the Strait of Juan de Fuca. They appeared in
almost all the tidepool collections along the strait and were especially
common at Observatory Point and Slip Point. Gammarid amphipods and hippolytid
shrimp together formed 84.0% of the total IRI. Fish (including Pholis sp.),
sphaeromatid isopods (including Gnorimosphaeroma oregonensis, Exosphaeroma
amplicauda, and Dynamenella sheareri), polychaete annelids, and pagurid
(hermit) crabs (including Pagurus beringanus) were of secondary importance
(Fig. B-34).
Leaman's (1976) collections of smoothhead sculpins in the Nereocystis
kelp beds in Barkley Sound, outer Vancouver Island, indicated that amphipods
(caprellids, Caprella equilibra, C^. incisa and gammarids, Photis bifurcata,
P_. californica) composed the highest proportion of the prey, followed by
shrimp (Betaeus setosus, Lebbeus lagunae), crabs (Pachycheles sp., Podocerus
sp.) and fish (northern clingfish, longfin sculpin).
Rosylip Sculpin
While not found abundantly during the DOE studies in northern Puget Sound,
rosylip sculpins were ubiquitously distributed among the intertidal collection
sites along the Strait of Juan de Fuca. In that region gammarid amphipods
(67.8% of total IRI) and sphaeromatid isopods (including Gnorimosphaeroma
oregonensis, Exosphaeroma amplicauda, and Dynamenella sheareri; 20.8%) composed
the majority of the IRI prey spectrum (Fig. B-35). Idoteid isopods (including
Idotea wosnesenski), polychaete annelids, crustacean larvae, and mysids
(including Archaeomysis grebnitzki) composed most of the remaining important
prey organisms.
132
-------
INDEX OF RELRTIVE IMPORTUNES (I.R.I.) OIRORflH
FROM FILE IDENT. 76-78. STRTION RLSIfi
8831020403 - RRTEOIUS LflTERflLIS
SMOOIHHERO SCULPIN
RDJUSTED SWLE SIZE = 77
20
40
CUMULATIVE FREQUENCY OF OCCURRENCE
PBEY ITF"
(••Au»ABIOE>
HTC°ni YTTDAF
«PHAFPO"I»TIOAE
TELECISTE1
PAOIRlOAE
NATANT1 A
r.AcTonpnnA
CPUST ACEA
POT AMOGFTONACF AE <'
P"1LIOir>AE
UNinFNTlFlED
k-ACPACTICOini
PA* OAL I naF
DH"ricPHYTA
FOEO
OCCUR
46.75
14.29
10.19
7.79
5.19
2. SO
?.*a
1.10
1.10
1.30
NUM.
11.11
3__03
2.53
2.53
U52_
1.01
1.5?
L.0_l_
1.01
3.01
L.01_
1.01
1.01
l.ni
1.01
COMP.
10.69
J?j91_
19I37
_S.70_
7.66
!o8
.0?
^94
.04
.25
_LO_,80_
.25
.00
L.64
.02
PREY PERCENT
I.R.I. TOTAL IRI
_?_?5.1
193.1
2*3.?
68.0
66.?
36.4
A,n
2.8
4.0
5U
2.7
8.S
30.7
3.1
1.1
1.3
62.37
21.59
*.51
5.6"
1 .so
1.54
.85
-19
.07
.09
.1?
.06
.20
.7?
.08
• 03
.11
.03
PPFY TAi* *1TH FOFC.
~
_FOF_O. irCi_io_._LE5<:_TMAN 5 ANn NUMF.OICAL J^iO GRAVIMETRIC
'" l'
-------
o
o
INDEX OF RELflTIVE IMPORTfiNCE U.R.I.) OIHCRBM
FROM FILE IOENT. 76-78. STflTION PLSTfl
8831020501 RSCELICHTHYS RHOOORUS
ROSYLIP SCULP IN
flDJUSTED SflMPLE SIZE = 276
20 40
60
80
100
120
140
PUEY ITEM
CUHULBTIVE FREQUENCY OF OCCURRENCE
FREO NUM. GRAV. PREY PERCENT
OCCUR COMP. COMP. I.R.I. TOTAL IRI
160
GAMMABIDEA
<;pHAFJ>OMATIDAE
lOOTEIOAE
POLYCHAETA
Mve;!OArFA
GAMMARIDAE
PAOIIOIDAE
OXRHYNCHA
UNIDENTIFIED '
HIPROl.YTIOAF.
CRUSTACEA
COTTlDAE
61.59
31.5?
9.4?
9.4?
«..BB
3.43
4.15
•>. an
2.54
7.54
1.81
1.45
1.45
1.09
?9.66
9.87
1.01
2.54
7.71
6.20
.37
!2S
.21
.17
4?. 37
.11
.08
14.76
17.33
17.76
10.07
1.91
5.21
2.89
1.53
1.7?
3.87
1.55
.15
5.23
2.47
1.29
1.31
857.7
176.9
U8.R
4-;. a
67.0
14.2
4.4
S.n
7.4
3.1
61.6
2.»
1.1
.5 —
66.32
20.78
4.29
2.88
l -l \
1.50
.34
.30
• 11
.1?
.18
.08
1.49
.19
.07
.03
.01
PPFY TA«> >_m(_F-PF,_0._OCCMR.. LESS TH«N_5 _»N[> NUMERICAL ANO__GPAy I METRIC
COMPOSITION HOTM LESS >MAN 1 AUE EXCLUDED FPO" THE TARLE AND PLOT
(HUT MOT FROM CALCULATION OF DIVERSITY INDICES!
PEPCENT OnulNSNCF INOE«
SHANNOM-ME^'ER DIVERSITY
.?»
2.41
.44
.11
3.75
.66
.49
1.61
Fig. B-35. IRI prey spectrum of rosylip sculpin in littoral habitats
along Strait of Juan de Fuca.
134
-------
Caprellid (Caprella incisa, £. equillbra) and gatnmarid amphipods
(Parapleustes pugettensis, Advoides sp.) were the principal prey of rosylip
sculpins in the Nereocystis kelp bed habitat in Barkley Sound, outer Vancouver
Island (Leaman 1976).
Padded Sculpin
Principal prey of padded sculpins from northern Puget Sound were
gammarid amphipods (89.1 percent of total IRI) and several other epibenthic
crustaceans—the flabelliferan isopod (Gnorimosphaeroma oregonense) (6.5
percent) and tanaids (3.0 percent). In these collections from the eastern
shoreline (i.e., Legoe Bay) gammarid amphipods also were the most prevalent
prey (88.7 percent of total IRI), followed by unidentified Caridean crustaceans
(shrimp; 5.7 percent), and sphaeromatid isopods (3.7 percent) (Fig. B-36).
In the Strait of Juan de Fuca padded sculpin were common at Twin Rivers
and Beckett Point, and were especially abundant in winter. Epibenthic
crustaceans—gammarid (including Corophiidae) amphipods, hippolytid shrimp
(Heptacarpus kincaidi, H. tenuissimus). crangonid shrimp, sphaeromatid
isopods (Gnorimosphaeroma oregonensis and Exosphaeroma amplicauda), and
idoteid isopods (Synidotea sp. and Idotea wosnesenski)—were more abundant
than benthic prey organisms such as polychaetes (Fig.B-37).
Silverspotted Sculpin
In northern Puget Sound silverspotted sculpin commonly appeared in the
pocket gravel beach habitat (Deadman Bay) beach seine collections from July
through October. The spectrum of prey identified from these specimens was
oriented toward epibenthic crustaceans, specifically gammarid amphipods
(40.1 percent of total IRI; including Amphithoe sp.). flabelliferan isopods
(39.6 percent) and shrimp (9.6 percent; Heptacarpus stimpsoni) (Fig. B-38).
Silverspotted sculpin specimens from cobble and gravel habitat sites at
Cherry Point, Shannon Point, and Legoe Bay appeared to be even more specialized
in their diet. Gammarid amphipods were 32.7 percent of the total IRI, shrimp
7.2 percent.
Of the sites sampled along the Strait of Juan de Fuca, beach seine
collections at Twin Rivers, Morse Creek, and Jamestown generally provided the
most silverspotted sculpin. The prey spectrum (Fig. B-39) was almost evenly
divided between mysids and gammarid amphipods.
Roughback Sculpin
Roughback sculpin were collected in the shallow sublittoral habitat only
in the Strait of Juan de Fuca, in winter beach seine collections at Beckett
Point. Shrimp, including hippolytids such as Heptacarpus tenuissimus,
crangonids such as Sclerocrangon alata and Crangon sp., and unidentified
pandalids, composed 83.5% of the total IRI. Gammarid amphipods and polychaete
annelids were of minor importance (Fig. B-40).
135
-------
g
£
I
§
CO
o
fe
8
INDEX OF RELRTIVE inPORTRNCE (I.R.I.) OIRGRRM
FROM FILE IDENT. UW BS. STRTION RLL
PREOflTOR 8831020401 - flRTEOIUS FENESTRRLIS
(PRDOEO SCULP IN ) HDJUSTED SRMPLE SIZE = 15
100
80
60
40
20
° 20
40
SO
80
100
20
40
60
80
100
120
140
160 180
200
CUMULHTIVE FREQUENCY OF OCCURRENCE
PREY
ITEM
FREO
OCCUR
NUM.
COMP.
GRAV.
COMP.
PREY
I.R.I.
PERCENT
TOTAL IRI
GAMMAP.IDEA SO.OjO 47.92
"SPHAEROMATID»E 33.00 2.92
PLEOCYEMATA-CARIDEA 20.00 1.67
_HARPACTICOJ_OA 13.00_ 3.33
TAK'AIDACEA . - - - n.oo " .83
POLYCHAETA 7.00 .42
EDCARIDA-DECAPQOA-BPACHYRHYNCH
BIVALVIA " " 7.
PROSOBRANCHIA 7.
i-RRACHYRHYNCH 7.00 .42
00
00
42
83
42
_LSO£ODA 7 . 0_0_ 1 .25__
12.14
3.23
13.69
.13
.16
.03
.33
.26
.33
1.32
4804.8
202.9
307.?
45.0
12.Q
3.2
5.J3
7.6
5.3
18. Q.
PP. 7Q
.70
.70
.80
.20
.10
.10
.10
.10
OO
PREY TAXA WITH FREO. OCCUR. LESS THAN 5 AND NUMERICAL AND GRAVIMETRIC
_COMPOSITION ROTH LESS THAN 1 ARF EXCLUDED FoQM THE TABLE_ANO PLOT ___
(BUT NOT FROM CALCULATION OF DIVERSITY INDICES)
PERCENT DOMINANCE INDEX_
"SHANNON-WFINEP DIVERSITY
EVENNESS INDEX
.23 .03
1.21"" 1.11
.37 .33
.79
.70
.21
Fig. B-36. IRI prey spectrum of padded sculpin in shallow sublittoral habitats
along eastern shoreline of northern Puget Sound.
136
-------
o
0-
§
100
80
60
40
20
INDEX OF RELFtTIVE ItlPORTRNCE (I.R.I.) OlflGRRM
FROM FILE IDENT. 76-78. STRTION flLSTfl
8831020401 - flRTEDIUS FENESTRflLIS
PflDOED SCULPIN
flOJUSTEO SflMPLE SIZE = 143
2 20
40
to
o
fe
o
o
60
80
100
oj nj eu -o m a)
m 01 o IH n , «
SE IH S H
20
40
60
80
100
120
140
160
CUMULATIVE FREQUENCY OF OCCURRENCE
FPEO NUM. GPAV. PPEY PERCENT
OCCKR COMP. COMP. I.P.I. TOTAL IRI
p^^A
f, AMMAPJOAF
ii'HOFKJTjritn
>> ftTAK'TI A
I OP TF I n AE
MYSinACEA
TAKiAjnarEA
CANCpTnAE
PArnoIDAE
_F IIC An I nA-nFCAonoA^-QPArpYPHYNC
CriPOPHi PJAE
CTITHAF IPAF
IB.lfl
IS. 39
11. R9
4.79
5.S9
"..'0
?.90
'».... ?.io .
'.10
.70
vl3
5.7S
1 .09
3.17
1 .79
.40
.99
.40
1.19
.in
S.06 ]
16.53
2.23
10.62
1 ft 1
l.'lS
.1?
L5.23
3.96
4.10
.09
6.79
ms.fi 43
463. fl 15
315.4 10
.11B.3 10
100.' 3
143. n 4
1C -,
B.O
.59.0 1
12.?
9.4
9.4
3.S
1.9
4.R
1.73
.19
.33
.47
.09
.71
.72
.96
.40
• 31
.31
.1?
.06
.16
POFY Ttxi *TTH FOEO. iccnp. LESS THAN •; ANO NUMEPICAI ANn GPAUIMFTOIT
_.CnMP«|T.ins POTH LE,, TH.N , APE E.CLi.Otn FPOM THE TAR*E ANn ^LOT
(RuT NOT FPOM CA|CULATION OF nivEOSITY INDICES)""
ifjnF»
CIVEOSITY~
3.37
.66
^
3.51
.69
-
?.64
.51
Fig. B-37. IRI Prey spectrum of padded sculpin in shallow sublittoral
habitats along Strait of Juan de Fuca.
137
-------
INDEX OF RELRTIVE IttPORTRNCE (I.R.I.) DIHGRRM
FROM FILE IDENT. N PGSD. STRTION RLSTfl
PREDRTOR 8831020602 BLEPSIRS CIRRHOSUS
(SILVERSPOTTED SCULP ) RDJUSTED SRMPLE SIZE = 20
UJ
(_>
Q
1
d
100
80
60
40
20
2 20
CD
40
| 60
o
o
,-i so
100
u C 0.
U) fll (0
OHO
20
40
60
80
100
120
CUflULRTIVE FREQUENCY OF OCCURRENCE
PPEY I
Fl.BFttlFE*.—
CAWMAR IDEA
PLFOCYEWATA-CAO
pr U&CARIDA-SPEL
OSTRACODA
TAK'AIDACEA
CAPPELLIDFA
...... - FPEQ —
TE" OCCUR
.._ lc.>no
35.00
'IOE4 --- 15.00 —
AFor,pAoHACEA l^.no
=•.00
5.00
.... _ _ . S.OO
5.00
NUM.
COMP.
43 ?4
40.54
4.05
7.43
"? • 03
1.35
.68
.68
GRAV.
COMD.
8.44
P2.88
?5.30
4P.45
.57"
.15
.00
.19
PPEY
I.R.I.
1BOB fl
??19.7
440.?
748.?
13. n
7.5
3.4
4.3
PFRCENT
TOTAL IRI
34.50
4?. 30
8.40
14.30
• ?0
.10
.10
.10
pppv TA«A WITH FDEO. nccu". LE<;<; THAN 5 ANO NUMERICAL ANO
CluPt^ITlnN «nTM-cE<;s THAN I ARE EXCLUDED TPOM fHF. TABLE ANO PLOT
OUT MOT FROM CALCULATION OF DIVERSITY INDICES)
PERCENT DOMlNflNCF INDEX
<;HnMNO'J-WF INFP DIVERSITY"
EVENNESS INOE«
.36
1 .«i
.60
.30
1 .89
.67
.33
1.80
.60
Fig. B-38. IRI prey spectrum in silver-spotted sculpins in shallow sub-
littoral waters of northern Puget Sound.
138
-------
100
INDEX OF RELRTIVE IMPORTRNCE (I.R.I.) DIRGRRM
FROM FILE IOENT. 76-78. STflTION RLSTR
8831020602 - BLEPSIRS CIRRHOSUS
SILVERSPOTTED SCULP
RDJUSTED SRMPLE SIZE = 132
DOEY ITEM
CUMULflTIVE FREQUENCY OF OCCURRENCE
FPEO NU«. &OAV. POEY PFPCENT
OCCiJO COMP. COMP. I.R.I. TOTAL IRI
uycnACEA 64. 19
r.af'io inFA _ 54.55 _
r.a>"'6«I riiF 25.76
1 nnTF IDAE 6.R2
»fcTA>:TLA. -- 6.06--
HIPPOLVTlnAF 6.06
CP^N^.ONinAE .76
CYCLOPTES1DAE. . . _. . .76-
41.11
4Q.65
11.35
1 .00
- 1 .64
.90
.11
.05 _
36.76
28.21
12.81
8.02
2.46.
3.61
1.85
- 1.85
5144. 1
1756.4
622.4
61 .5
24.8
27.1
1.5
1.4
51.32
3H.93
6.45
.64
.26 __.
• 2»
.02
.01
ooff T»«A
-------
§
o
lOOr
80
60
40
20
INDEX OF RELATIVE IMPORTANCE (I.R.I.) DlfiORflM
FROM FILE IDENT. 76-78. STRTION RLSTfl
8831024001 - CHITONOTIS PUCETENSIS
ROUGHBHCK SCULPIN
RDJUSTED SRMPLE SIZE = 39
§ -20
40
60
-80
100
TF
•Q 'H
C W
P- ~'
* -H
>, U
JH *H
a w
o o
o a.
20
40
60
80
100
120
140
160
PPEY ITEM
CUMULflTlVE FREQUENCY OF OCCURRENCE
FPEO
nccim
NUM.
COMP.
COMP.
POEY
I.P.I.
PERCENT
TOTAL IPI
HIDPOLYTIDAE
M4TANTJA
"
TAKA10ACEA
MALACOSTPACA PHYLLOCAPIDA
.
HAPPACTICOIDA ______
35.^0
?3.ne
17.QS
i5;. is
1^.13
7.«,q
7.f>9
5.13
^.13
S.13
=-.13
«.13
?.<;6
2.56
15.07
in.?7
5.'.S
8.2?
?3. . 14
1.23
9.13
.43
4.0<(
fc.19
.00
.05
5.62
.32
.00
.00
1600.0
?66.5
890.6
1<^.<>
509.2
19.1
5?. 14
28.5
7.0
7.1
35.9
8.7
3H.6
24.6
44.01
7.33
24.50
4.00
14.01
.53
1 .44
.. .78
.19
.?0
._ .90
.24
1 .06
.68
PPFY TAXA dlTH FPEO. ICCllR. LFS^ THAN 5 AND NUMERICAL ANP GPAVIMETPIC
_£OuonsITION BOTH LE5« THAN I AHF E»CLIlO£0 FROM THE TAHLF Awn PLOT
(P'JT MOT FPOM CALCULATION OF DIVERSITY INDICES)
PERCENT DOMINANCE INDEX
SHANNO'J-WF INFO DIVERSITY
EVENNESS INDE»
.13
3.21
.30
2.20
.56
.28
2.31
.59
Fig. B-40.
IRI prey spectrum of roughback sculpin in shallow sublittoral
waters of the Strait of Juan de Fuca.
140
-------
Sharpnose Sculpin
Sharpnose sculpin were found to be common members of the tidepool fish
assemblages along the Strait of Juan de Fuca, especially at Slip Point, Morse
Creek, and North Beach, but only at Point Williams were they collected by
the beach seine. Gammarid amphipods and sphaeromatid isopods (Gnorimosphaeroma
oregonensis, Exosphaeroma amplicauda, and Dynamenella sheareri) made up
94% of the total IRI (Fig. B-41).
Calico Sculpin
The stomachs of several calico sculpins collected at Fidalgo Island
(Anacortes region) contained 23 gammarid amphipods and nine harpacticoid
copepods.
Along the Strait of Juan de Fuca, however, calico sculpin appeared often
in tidepool collections, mostly at Observatory Point and Slip Point. As with
the sharpnose sculpin, gammarid amphipods and sphaeromatid isopods made up
the majority of the IRI prey spectrum for the calico sculpin: however,
barnacles (principally cirri) were also a numerous (40% of total prey abundance)
component in the diet (Fig. B-42).
Mosshead Sculpin
Mosshead sculpins were not included in the collections in northern Puget
Sound, due, perhaps, to the lack of sampling in rocky littoral habitats as
they were often included in tidepool collections along the Strait of Juan de
Fuca. They were particularly abundant at Slip Point and Observatory Point.
The diet was more diverse and quite different from the other two Clinocottus
species. Barnacles were the predominant prey organism while gammarid amphipods
and sphaeromatid isopods did not contribute significantly to the diet (Fig. B-43).
Algae (including Urospora mirabilis, Porphyra sp. , and Iridaea sp.) composed
38.7% of the total IRI, followed by harpacticoid copepods, sabellid annelids,
nemertean worms, and ostracods.
Buffalo Sculpin
Buffalo sculpins caught in northern Puget Sound had in their stomachs
numerous pieces of algae (ulvoid type), constituting 61.8 percent of the total
IRI, accompanied by two amphipods (25.0 percent), and one partly digested fish
(13.2 percent). The sample size was too small, however, to determine whether
the consumption of algae is representative of the food habits. Buffalo
sculpins originating from the Cherry Point region also indicated a high
contribution by algae. Nonalgae prey taxa included gammarid amphipods
crab! ?sTf ^tal ??' ±nSeCtS (11'2 Pe««*), polychaetes (9.2 percent),
and orlanic dehrf O^ 3nC^ (4'7 Perce*t), pychnogonids (4.1 percent), sticks
and organic debris (2.5 percent), and flabelliferan isopods (2.4 percent'
primarily Exosphaeroma amplicauda). percent,
Among the beach seine collection^ alnr,™ «-K~ o_
juvenile buffalo sculpins were most common^ Twin *£"» *Tl *t ^
Tidepool collections at Observatory Point and N^rtb^I ^ *? k6" P°int'
specimens. Gammarid amphipods, algae (IncSint JV ° pr°vided a few
Ulva fenestrata, Porphyra sp., 8
annelids were identified as the
141
-------
m
z
o
I—
CO
o
o_
c
o
o
INDEX OF RELflTIVE IMPORTRNCE (I.R.I.) DIRGRfiM
FROM FILE IOENT. 76-78. STflTION fiLSTfi
8831020701
lOOr
80
60
40
20
" 20
40
60
80
100
P3EY ITFM
CLINOCOTTUS flCUTICEPS
SHPRPNOSE SCULPIN
flOJUSTED SfltlPLE SIZE 124
20
40
60
80
100
120
140
CUMULRTIVE FREQUENCY OF OCCURRENCE
ncciip
NUM.
COMP.
COMP.
PPEY
1 .0.1
PFRCENT
TOTAL IRI
15.65 3?.P6 33.^9 36"?.
OIPTFBA
HAB3ACTICOIOA
1DCTF.1QAE ..
UNIOFNT IFIEH
MY«:IDACFA_
10.4*)
.81
17.14
3.76
9.6?
-1.1?
1.51
-17.87. .
.94
.23
. 1.35
3.11
.56
.01
3.87 ?7.86
53.0
103.3
12.9
92.3
7.9
._ 3.7.
1.?
33.7
67.08
21- IS .
.96
1.8*)
1
6*)
14
07.
02
61
PPFY TAXA WITH FOFO. OCCllW. LESS THAN 5 AND NUMERICAL AND GPAvIMETPIT
COMPOSITION <>OTH LESS THAN 1 APE EXCLUDER FPQM THE TABLE AN1 PLOT
(RUT MOT FRO«.CALCULATION OF OIVESSITY INOITES)_
PEPCFNT DOMINANCE INOEX
SHANNOM-KF1NKP DIVFPS1TY
EVEMNtSS INDEX
.)»
?.9?
"
.29
2.14
.49
.52
1.27
.29
Fig. B-41.
IRI prey spectrum of sharpnose sculpin in shallow sublittoral
and littoral habitats along the Strait of Juan de Fuca.
142
-------
100
80
60
40
20
20
40
60
80
100
INDEX OF RELRTIVE IMPORTRNCE (I.R.I.) DlflORflM
FROM FILE IDENT. 76-78. STRTION fllSTfl
8831020702 - CLINOCOTTUS EflBRYUM
CRLICO SCULP IN
ROJUSTEO SRMPLE SIZE - 20
u tj « «
ffl O *J 14
u m u v
20
40
60
80
100 120 140 160 180 200
PSJFY ITFM
CUnULRTIVE FREQUENCY OF OCCURRENCE
FPEO NUM. GPAV. PPFY PF9CENT
OrCuo CO"". COMP. I.R.I. TOTAL I&I
cpHAFOOVftTlOAF
Ml)' >l!DAF
wACPACTICr-IOA
JUPTEPl . . _
7o.no
5n.oo
3n.io
in.no
IP. 00
s.on
s. no
5. no
26.19
40.48
1.79
— . 1.19_
4.7*.
1.79
1.7.9
66.52
21 .54
4. S3
.54
.05
.97
.. ...91.
•>419.8
?1 18.7
1350.3
23.?
50.9 _
24.1
13. •»
i3.a__
IS4.29
20.99
13.39
.23
.__._. 50
.24
.14
.14
POFY T».A bITH FPfO. OCCltP. LFSS THAN 5 AND NUMERICAL ANO GOAVIMETPIC
_rriMPOs!TION BOTH (.ESS TM»N 1 AHF E«CLlinEO Fop" THE TABLE ANO PLOT
(PijT NOT TRIM CALCULATION Or OIvEPSlTY INDICES)
PFOCFNT
INEO Dl"vER«SITY
?.19
^
1.50
.45
_
1.39
• 4?
Fig. B-42. IRI prey spectrum of calico sculpin in littoral habitats along
Strait of Juan de Fuca.
143
-------
s
J—
8
5
5
tOOr
INDEX OF RELRTIVE IMPORTRNCE (I.R.I.) DIflGRRM
FROM FILE IDENT. 76-78, STRTION RLSTR
8831020703 - CLINOCOTTUS GLOBICEPS
MOSSHEflD SCULPIN
RDJUSTED SflMPLE SIZE = 77
160
P=!EY ITEM
CUMULflTIVE FREQUENCY OF OCCURRENCE
•"pfo NUM". 'GPAV." "PREY PERCENT
OCCUR COHP. COMP. I.R.I. TOTAL IRI
CIBPIPfDIA
..UJLaTRlCHALES
UNIDENTIFIED
ME«EPTFA
-GAMMApiDEA
pMnrjnRHYTA
H»OPACTICOIOA
CHLOOOPHyT*
«ARFLLIOAE
rPHAEPO"ATIOAF
.C.STOAC.onA .
ACRO^lPrtrtNlACFAE
POI VCMA<"T«
PAVGIACEAE
GACTRDPODA
C-ir:AOTlN4C E»
31.17
.23.J8
10. 4«
1 1 .ft9
10.39
in.. 19
9.09
9.09
S.19
S.19
, -3.90
?.f>0
?.«)0
?.ftO
?.isn
?.«,o
fcl .89
_.6.22
4.3?
1.35
1.22.
?.70
9.71
1.76
11.7ft
.54
10.54
1.76
.?7
.?7
1.08
3.78
3.68
30.04
?3.??
?.8S
.78
4.75
.26
13.63
1.95
.?4
1 .9«;
1.35
1.7?
3.00
.68
8.54
1420.1
847. 6
*36.7
49.1
20.7
77.4
90. »
139.9 _
71.?
4.1
48.7
8.1
5.?
8.5
4.6
3?.0
4?. 17
.25.17 __
15.93
1.46
-. .62. _
?.30
2.70
. 4.15 _
?.ll
.1?
l.*5 . _
.24
* 15
.25
.14
• 95
PREY TAXA WITH FPEO. OCCUR. LE^S THAN 5 AND NUMERICAL AND
COMPOSITION ROTH LESS THAN 1 AHF EXCLUDED FPOM THE TARLE AND PLOT
(J?_MT_ NOT FRO" CA| CULATION OF DIVERSITY INDICFSI _
PTOCENT
2.9? 3.05
.67 .69
.27
•'•O.
.55
Fig. B-43. IRI prey^spectrun, of mosshead sculpin in littoral habitats along
the Strait of Juan de Fuca. &
144
-------
spectrum (Fig. B-44) . The high incidence (31.5% of total IRI) of algae a
suggests that they may constitute more than an incidentally consumed rou
Adult buffalo sculpin collected in a gravel-cobble habitat in Nisqually
Reach, southern Puget Sound (Fresh et al. 1979), had consumed algae (also
principally ulvoid types) almost exclusively, such that 93% of the total IKi
was algae. Most of the prey animals were gammarid amphipods and polychaete
annelids. Johnson's (1968) in-depth analysis of the food habits of buffalo
sculpin in Humboldt Bay, California, indicated that caprellid (Caprella sp.)
and gammarid amphipods (inc. Amphithoe sp.) were the predominant food
organisms, composing 66.3% of the total IRI spectrum (Fig. B-45) . Again,
algae (Ulva lobata) were a major component (16.4% of total IRI) in the diet.
Red Irish Lord
Red Irish lord were characteristic of the demersal fish assemblage in
the gravel-cobble pocket beach habitats in northern Puget Sound and were often
found in the rocky/kelp bed habitat. They appeared to be an almost completely
bottom-oriented carnivore, preying on flabelliferan isopods (42.8 percent of
total IRI), brachyuran crabs (39.9 percent; Cancer magister, C^. oregonensis.
C. productus. Pugettia gracilis, Mimulus sp.), fish (13.4 percent), and
shrimp (1.3 percent).
Although they were not frequently collected along the Strait of Juan
de Fuca during the MESA studies, Leaman (1976) identified them as common
members of the Nereocystis kelp bed assemblage in Barkley Sound, outer
Vancouver Island, his documentation of their prey organisms indicated
approximately equal gravimetric contributions by crabs (Pachycheles rudis,
Loxorhynchus crispatus, Cancer oregonensis) . gammarid amphipods (Erichtonius
brasiliensis) and caprellid amphipods (Caprella equilibra. C. incisa C~!
natalensis, C^. laeviscula, jC . mendax , £. ferrea) . ~ ' ~
Longfin Sculpin
The longfin sculpin was the most frequently observed cottid and third
most common species over the combined SCUBA trains*^ ~u cnira
frequency of occurrence) in the rocky/kelp bed haMtat T^10"8 ^ PerCent
Sound. The prey spectrum was very diverse with Tn J * er° Puget
included in the overall sample. Harpacticoid COD J °f rare Prey ite*»s
prey, contributing 55.4 percent of the total TUT i WSre the most lmP°rtant
crabs (8.7 percent), gammarid amphipods (5 7 J, po|ychaetes (23.9 percent),
and crab larvae, (1.5 percent) were of second*™- ' shrimP d-5 percent),
benthic organisms were taken more frequently hi ^?°rtance- Although epi-
greatest contribution to the total prey biomass organisms made the
Longfin sculpins also appear tn
r n o
habitats along the Strait of Juan de F^^ef fT^" °f the ro<*y/kelp bed
data) and m the Nereocystis kelp bed habitat i ' ^±V' Wash- > unpub
Vancouver Island (Leaman 1976). In the 1»^ ^ the Outer coast of
(Parapleustes pugettensis. Photis calif ornlrf Z*K±°*' 8ammarid
appeared to be their most ^^u^l~~?-> ^ichtoniu
crustaceans and polychaete annelids SuPPlemented by
145
-------
100
INDEX OF RELflTIVE IMPORTANCE (I.R.I.I OIBGRflM
FROM FILE IDENT. 76-78. STPTION RLSTR
8831021001 - ENOPHRYS BISON
BUFFflLO SCULP IN
flDJUSTED SHMPLE SIZE = 116
S 20
100
20
40
60
80 100 120 140 160
CUMULRTIVE FREQUENCY
PPFY 1TFM
POI YCHAFTA
IINIOFNTIFIEO
III UATFAF
TANAIOACFA
GAMMAPinAE
HIPPOLYTIPAF.
PHnnoPHYTA
BIVALVIA
CHLOROPHYTA
CANCRIOAE
OSTEICHTHYS
PACURIHAE
ATFLECYCLIDAE
COTTID4E
CALLIANASSlOAF
HA»!NOEIOAE
CLIIPEIOAE
PHYI.LOOnCIOAE
FPFO
OCCIIP
4,. .18
15.52
10.14
10.34
8.62
6.90
6.03
5.17
4.11
4.11
3.45
1.7?
1.7?
1.72
.BIS
."6
NUM.
COMP.
G"AV.
COMP.
25.06 1.11
~ 6!27 2.17
S.90 7.01
I.** 35.26.
6.87 .40
3.98 .03
Z.65 U.1%.
2.41 .21
.84 .88
1.45 .92
1.20
4.34
.36
6.27
.60
.84
.60
.1?
.12
.47
9.50
.67
1.01
1.J7
5.60
3.33
2.33
1.S2
3.27
OF OCCURRENCE
PPF.Y
I.R.I.
41S.5 .
131.0
S0?.8_
75.?
34.5
9_S.J_
15.8
10.?
7.?
47.7
9.1
17.9
2.B
10.1
3.0
1.5
2.9
PERCENT
TOTAL IRI
40.25
15.54
4.86
7.03
18.79
2.79
1.28
3.54
.59
.33
.38
.27
1.77
.34
.67
.10
.13
.37
.11
.09
• 06
.11
_PPE.T_IAXA KITMJPEJ. OCCUg._J.ESS_tHAN 5 _ANO_ NUMERICAL
COMPOSITION POTH LESS THAN 1 APE FxCLIIHEO FPOM THE TAHLE ANO PLOT
(BUT NOT FROM CALCULATION OF DIVERSITY
PERCENT OOMINANC"; [HDF»
SHANNON-WE1NEP 01VEPSITY
.11
3.85
_.71
.19
.3fr
.62
.23
?.73
.50
Fig. B-44. IRI prey spectrum of buffalo sculpin in shallow sublittoral
habitats along Strait of Juan de Fuca.
146
-------
INDEX OF RELRTIVE IMPORTHNCE (I.R.I.) OIRORRM
FROM FILE IOENT. JOHNSN. STHT10N 1968
PREORTOR 8831021001 - ENOPHRYS BISON
(BUFFRLO SCULPIN ) ROJUSTED SHMPLE SIZE
100 r
•
1
~4
2
TJ O.
« a
• — a
EJ 5 1
SiSfl
• &•
",S|
"M
o 5
sld
100
Too iso 200
CUI1ULHTIVE FREQUENCY OF OCCURRENCE
FPEO NUM. G««V. POET PERCENT
nrdlP COMP. CQMP. I.P.I. TOTtL 1P1
ROCK
Gau">Rinf a
• AMFHITHOE SP.
NASSARIUS SP.
OHFl T* SP.
EULALIA AVICULISETA
M4CO"* SP.
II^TOFNT IF 1EO
ELAlMOfUS St.
10CTFA SP.
rp»i«ir,OM SP.
— pr>L»e*»E"i4
FLtBFLLIfERA
CLYCERA SP.
— NECII<; SP.
(TiMPn^TmKr>
LESS THAN 5 AKIO NUMERICAL Akin G°l
*RE F.ltLliOED TooM THE TABLE »nn
nivERSITT INOirfsi
.P2 .16
2.40 3.14
.65 .8?
33.40
10.30
24.10
16.40
3.80
.80
.30
.20
.40
.00
.30
.50
.10
.10
.00
.20
WIMET9IC
PLOT
.2?
2-51
.64
Fig. B-45.
IRI prey spectrum of buffalo sculpin generated from data
included in Johnson's (1968) analysis of their food habits
in Humboldt Bay, California.
147
-------
Pacific Staghorn Sculpin
Staghorn sculpins were probably the most ubiquitous cottid in the shallow
sublittoral region of northern Puget Sound. Considering the sample size from
this region, the overall prey spectrum (Fig. B-46) is not very diverse.
Emphasis is on benthic organisms, with flabelliferan isopods (32.2 percent
of total IRI), and bivalve siphons (29.6 percent) being equally important;
polychaetes follow with 11.5 percent. Crabs account for 8.9 percent of the
total IRI; fish, 51.7 percent: crab larvae, 4.3 percent; tanaids, 3.3 percent:
gammarid amphipods (including Atylus sp., Allorchestes sp., Paraphoxus
spinosa, and Euhaustorius sp., Paraphoxus spinosa, and Euhaustorius sp.), 1.3
percent; and bivalves, 0.5 percent. Although not as frequently preyed upon,
fish (including juveniles and larvae of Pacific herring and juvenile striped
seaperch, Embiotoca lateralis) and oxyrhynchan crabs actually composed the
majority of the biomass ingested. Included in the decapod and general
peracaridan crustacean categories were Crangon franciscorum, Idotea resecata,
and Cancer magister.
Also, the most common nearshore demersal species collected along the
eastern shoreline, they occurred dominantly in collections at the Fidalgo Bay,
Drayton Harbor, and Padilla Bay mud/eelgrass sites and the Brich Bay sand/
eelgrass site. Overall prey composition from the eastern sites is dramatically
different than those in the western area (Fig. B-47). Gammarid amphipods
are much more important, providing 69.8 percent of the total IRI. Other prey
taxa are rather equally represented by crabs (8.8 percent, Hemigrapsus
oregonensis, E. nudus, Cancer magister, Pinnixa sp., and Paguridae), shrimp
(8.2 percent; Crangonidae, Callianassidae, including Upogebia pugettensis,
and Penaeidae), isopods (5.7 percent, Exosphaeroma amplicauda, E_. media) ,
fish (3.2 percent; juvenile Staghorn sculpins, shiner perch, and rockfishes),
and polychaete annelids (3.2 percent).
Along the Strait of Juan de Fuca, Pacific Staghorn sculpin were one of
the few nearshore demersal species which occurred commonly in the beach seine
collections at all sites; however, collections at Jamestown and Beckett Point
provided more specimens than the other sites. The diverse prey spectrum
(Fig. B-48) included both benthic and epibenthic organisms and, unlike the
northern Puget Sound spectrum, was dominated by fish (46% of total IRx, including
buffalo sculpin, Enophrys bison, shiner perch, Cymatogaster aggregata, Pacific
sand lance, tube-snout; Aulorhynchus flavidus, juvenile salmon, Oncorhynchus sp.,
other Pacific staghorn sculpin, Leptocottus armatus, and unidentified flatfish,
Pleuronectidae), true shrimp (17.5% of total IRI, including Heptacarpus taylori,
Pandalus danae, Crangon alaskensis, and C_. stylirostris) , mysids (11.7% of total
IRI, including Neomysis awatschensis), polychaete annelids, and crabs (6.2% of
total IRI, including Pugettia richi, Telmessus cheiragonus, Cancer magister,
and Hemigrapsis oregonensis).
Jones (1962) extensive studies of Leptocottus populations in Tomales Bay,
California, included documentation of an overall diet oriented almost exclusively
toward benthic shrimp (Crangon sp. and Upogebia pugettensisa, 92.3% of total
IRI combined); fish (northern anchovy, Engraulis mordax and shore crabs
(Hemigrapsus oregonensis) were secondary prey organisms (Fig. B-49). Life
history studies of staghorn sculpins in Anaheim Bay (Tasto 1975) similarly
illustrated both the variety of food organisms consumed and the importance of
decapod crustaceans, specifically Pinnixa sp., Hemigrapsus oregonensis and
148
-------
INDEX OF RELRTIVE IMPORTANCE (I.R.I.) DIHGRflM
FROh FILE IDENT. N PGSD. STflTlON flLSTfl
PREDHTOR 8831021801 - LEPTOCOTTUS flRMRTUS
(PRC- STRGHORN SCULPN) flOJUSTED SflHPLE SIZE = 51
y
g
I
o
*—
o
100
80
60
40
20
2 20
40
AJ O U
£ »w O
O -H 4J
•H 01 O
o) C.-H
w 3 .fl
« T-I e
O U W
S.-S
01
O
»-i U > 4J
QJ 0) -H 10
PL. Q PQ O I
50 100 150 200
CUMULflTIVE FREQUENCY OF OCCURRENCE
250
MUM; GRAVi— v°Ef PFPCENT
OCCUR COMP. COMP. I.R.I. TOTAL IRl
POLYCHAET6 — — .
f . AUCI 1 T F F Q A
r (_ B 7*r l_L 1 * t w *»
G AMM AO 1 OF A " " " — — -- —
PF CAPOOA — flOACHVllPft
p 1 V fi L v T ft -
TAKftlDACFA.
O^C&°OOft - _
pt DAPARinfi — CDTi ArnrnAnL.A/-r>
»'c.H'*i,'«**iuiivti^r LAtOoRAP^flCEA
- DtC»DOOA-RRACMTI|0« -- --
BIVALVI A
— O^TEICMTHYE^
OXYRHYNCHA
CL'fPEA HAPENGM*^ DA[tA<:l
O^TF ICHTHvFc
TLIIOE IFOO"E<;-CLUPEnlDFI
FMPlnTOCA LiTFoALK
47.00
?4.00 3
??.oo
?'.no
?n.oo " ?
IB. oo
16.00
10.00
«.00~
i.no
— «. . o o — -
fi.no
?.oo
?."0
2. no
?.no
4. 06 --
13.4?
1.7? —
«.l?
3.5T
?.50
1.39 -
.69
?.«5 --
1 .64
.35~
.43
.09
.09
.09
.17
6.06
3.14
~ .19 —
3.12
6.8?
?.53
6.14
.53
.73
.14
14.31
18.??
4.06
1 .50
1.2?
?7.54
475.6^"
S77.4
41. P
315.9
«06";^"
90.5
120.3
12.2
29. f,
14.?
98.0
111.9
8. 1
3.?
2.6
S5.4
" 15.60
28.70
1 .40
1 0.30
?6 .40
3.00
3.90 "
.40
.90
.50
2.90
3.70
.30
.10
.10
1 .80
PPFY 'All
-------
INDEX OF RELRTIVE IMPORTANCE (I.R.I.) DIRGRRM
FROM FILE IDENT. HH BS. STRTION fiLL
PREDfiTOR 8831021801 LEPTOCOTTUS flRtlflTUS
CPfiC. STRGHORN SCULPN) fiDJUSTED SRHPLE SIZE - 91
100
3
80
60
§
" 40
tn
o
a.
§ 20
\—
o
°~ o
t—
s
2 20
§ 40
^~"
I 60
hi 80
o
Q_
inn
•
ffl
01
(U
1
u
— 1 — I — I — I""1 n r*"*
^ ^ — ~* — 1 1 [ I
^u u
, :
.
-o i-
-p- T3 3
5 S « 1
*J 4J ocj
20 40 60 80 100 120 140 160 180 200
CUMULflTIVE FREQUENCY OF OCCURRENCE
PPEY ITEM
FREO NUM.
OCCUR COMP.
r,RAV. PPEY PERCENT
COMP. I.P.I. TOTAL IRI
_GAMM4RJOE4_
POLVCHAETA
PENAEIDAE
GRAPSIOAE
ISOPODA " "
OSTEICHTHYES
PLEOCYEMATA-CARIOEA
FUCAPIDA-DECAPODA-BRACHYRHYNCH
CALLIANASSIOAE
SPHAERQMATIDAE_
EMPIOTOCIOAE"
COTTIDAE
VALVITERA _
DECAPODA-8RACMYURA
CANCRIDAE
4 ? . 0 0
2?.00
18.00
lfc.00
1A.OO
1P.OO
9. no
B.OO
6.00
•5.00
fc.no
4.00
3.00
?.oo
1.00
sn.n?
3.8ft
4.13
1.33
11. 9B
1.70
1.31
l.?0
.93
1 .ftn
.93
.53
1 .fiO
4.13
.13
1.97
4.24
7.10
18.00
.2«
5.57
3.38
3.78
1?.7?
.09
13.81
7.3?
.30
2.13
17.49
??37.7
178.?
?0?.l
?98.«,
175.S
87.?
42.4
39. p
S4.6
«.4
59.0
31.4
5.7
12. S
17.6
64.5n
5.10
5.8n
».60
5.10
?.SO
_l.?n
1.10
1.60
.20
1.70
.90
_ •?"_
.40
.50
PRPY TAX* WITH FpEO. OCCUR. LE55 THAN'5 AND NUMEOICAL AND GRAVIMETRIC
COMPOSITION ROTH LESS THAN 1 ARE EXCLUDED FPOM THE TABLE ANn PLOT
(BUT NOT FROM CALCULATION OF DIVERSITY INDICES)
PERCENT DOMINANCE INDEX
SHANNON-WEINER DIVERSITY
EVENNESS
.?7 .1?
?.?? 3.26
.57 — .83
.43
2.03
.5?'
Fig. B-47- IRI prey spectrum of staghorn sculpins from shallow sublittoral
habitats along eastern shoreline of northern Puget Sound.
150
-------
INDEX OF RELflTIVE IMPORTANCE (I.R.I.) OIHORHM
FROM FILE IDENT. 76-78. STfiTION HLSTfl
8831021801 LEPTOCOTTUS flRflflTUS
PflC. STHOHORN SCULPN
flOJUSTED SfWPLE SIZE = 294
100
20
40
60
100 120 140 160 180 ZOO
CUnULflTIVE FREQUENCY OF OCCURRENCE
FOEO NU". CP»V. PPEY PERCENT
OCCIIH COMP. COMP. I.R.I. TOT»L 1RI
UHIOENT.FIED
CPAVGONIOAf.
Pni YCHAFTA
TFLEOSTFI
NATANTIA
H1DOOLYT IDAr
C»>roln«E
TAKA 1 DACF A
SP^AFROMATIHAF.
PA* OAL IOAE
FllCAOinA-OECAPnOA-flPACHYPMYNCH
OSTEICHTHYS
FIICAOIOA-nEClPOOA
COTTIDAF
ATFLECYTLIDAE
NFMATOOA
MYM1AE
CLUOEIOAE
20.41
20.07
15.65
11.61
11.9(1
10.20
9.86
0.50
7.«2
7.14
5.7C
5.7H
3.74
3.40
3.40
1.06
2.72
2.72
2.18
1.16
1.16
1.36
.34
2.33
_3.85_
1.24
9.06
.90
.74
.72
.49
.50
2.30
.S4
.29
.98
68.44
.!•*
.12
.10
.12
.n»
2j2l
1.76
.04
.16
.05
.01
4.46
.93
7.22
1.19
_2*«5
16.68
1.58
1.73
7.69
.03
.38
5.60
1.80
10.23
2.84
4.29
4.86
8.05
2.71
.05
2.63
1.04
1.30
1.12
152.4
97.6
169.7
160.4
207.3
23. S
69. A
18.?
34.0
16. 0
J94.4
10.3
15. n
15.?
22.?
7.6
5.4
3!6
?.7
1.8
10.73
6.87
11.95
11.29
1.21
14.60
1.6S
1.54
4.9Q
1.21
.46
2.40
1.13
20.73
.7?
1.06
J.07
1.57
.54
.38
.37
.26
.19
.13
• 03
PRFY TAIA HUM FPEQ. OCClH. LESS THAN 5 AND NUMERICAL AND GRAVIMETRIC
COMPOSITION «OT« LESS THAN I ARF EXCLUDED FOOM THE TABLE ANO PLOT
j9aLNOJLEflO"__£A.LCULA-I-lOM_OF_alvEP.SlT»_lNOICESJ
1MINANCF INOEH .48
rI"FO OIVFDSITY _2.|4
.07
4.4Q
•11
j.63
Fig. B-48. IRI prey spectrum of staghorn sculpin in shallow
sublittoral habitat of Strait of Juan de Fuca.
151
-------
INDEX OF RELflTIVE IMPORTflNCE (I.R.I.) DlflGRRM
FROM FILE IDENT. JONES. STflTION 1962
PREORTOR 8831021801 LEPTOCOTTUS RRMHTUS
(PRC. STflGHORN SCULPN) PDJUSTED SRMPLE SIZE
87
10U
1 80
CD
•z.
ID
GO
^ 60
00
•z.
o
E 40
Q_
S 20
\—
C_)
0
t—
§ 20
UJ
3
>-
CD
40
o
i—
£ 60
1
^ 30
<_>
Q_
100
Crangon sp .
Upogebia pugettensi:
) 50 100
,1,1 T"Dn
IP
,raulis mordax
nigrapsus oregonensis
dentif ied
eostei
lianassa longimana
cer magi s t er
jjiea harengus pallasi
cliis sp.
C Oi C Oi .'ANCE INDEX
OI
-------
Callianassa sp. (Table B-5). Fish, mostly.the arrow goby, Clevelandia ios,
also occurred frequently.
Leptocottus from Everett Bay, central Puget Sound, examined by
Conley (1977) had consumed mostly Corophium sp. and other gammarid amphipods,
based on numbers, while other Leptdcbttus armatus,and mud shrimp, Callianassa
sp., composed the majority of the total prey biomass (Table B-6).
Great Sculpin
Great sculpins were retained only in collections from northern Puget
Sound. One juvenile great sculpin from a beach seine collection at Deadman
Bay had two unidentifiable decapods in its stomach. Another from a beach
seine collection at Guemes Island contained 17 gammarid amphipods, 17 benthic
gastropods (Littorina scutulata) and a piece of alga.
Tidepool Sculpin
Tidepool sculpin were numerically the predominant fish in the intertidal
collections along the Strait of Juan de Fuca. They were especially abundant
at four sites—Slip Point, Observatory Point, Twin Rivers, and North Beach.
Gammarid amphipods and sphaeromatid isopod species (Gnorimo sphaeroma oregonensis
and Exosphaeroma amplicauda) dominated the prey spectrum (Fig. B-50),
combining for 80.3% of the total IRI. Harpacticoid copepods (8.2% of total
IRI), polychaete annelids (4.9%), and barnacles (4.3%) constituted the more
important secondary prey items. Sphaeromatid isopods were quite important
at the sites in the eastern half of the Strait but were only fourth or fifth
in importance at the three western sites: there barnacles and harpacticoid
copepods or hermit crabs replaced sphaeromatid isopods.
Nakamura's (1971) analysis of the food habits of tidepool sculpin at Port
Renfrew, on the west coast of Vancouver Island, B.C., showed harpacticoid
copepods and gammarid amphipods to numerically predominate; insects, polychaete
annelids and isopods were of secondary importance (Table B-7).
Saddleback Sculpin
The saddleback sculpin was reported only from tidepool collections at
Slip Point and Observatory Point in the Strait of Juan de Fuca. They had
fed primarily upon gammarid amphipods (Fig. B-51); the second most important
prey for the saddleback sculpin was harpacticoid copepods.
Fluffy Sculpin
Fluffy sculpins were common in collections from Slip Point, Observatory
Point, and Neah Bay along the Strait of Juan de Fuca. Among the three
Oligocottus species, gammarid amphipods contributed more to the prey spectrum
of the fluffy sculpin; accordingly, sphaeromatid isopods were the least
important in the diet of this species (Fig. B-52). The three isopod species—
Gnorimosphaeroma oregonensis, Exosphaeroma amplicauda, and Dynamenella sheareri—
were equally represented. Harpacticoid copepods, polychaetes, and idoteid
isopods were secondary food organisms.
153
-------
Table B-5. Prey composition (frequency of occurence) of Pacific staghorn
sculpin in Anaheim Bay, California documented by Tasto (1975).
PREDATOR 8831021801 - LEPTOCOTTUS ARMATUS
(PAC. STAGHORN SCULPN)
INDEX OF RELATIVE IMPORTANCE (I.R.I.) TABLE
FROM FILE IDENT. REF 67. STATION SLSTA
PREY ITEM
FREO NUM.
OCCUR COMP.
GRAV. PREY
COMP. I.R.I.
PERCENT
TOTAL IRI
PINNIXA
MEMIGRAPSUS OREGONENSIS
CALLIANASSA SP.
CLEVELAND IA IDS
OECAPODA
COROPHIUM ACHERUSICUM
TELEOSTEI
AMPHITHOE SP.
FUNDULUS SP.
HYALE PLUMULOSA
OECAPODA
OIPTERA
POLYCHAETA
GAMMARIDEA
OXYUROSTYLIS SMITHI
CRANGON SP.
EULALIA SP.
HYALE SP.
"TAGELUS SP. ""
GONIADA SP.
LEPTOCOTTUS ARMATUS
ALLORCHESTES SP.
CANCER ANTENNARIUS
POTAMIDIDAE
ATHERINOPS AFFINIS "
HYALE RUBRA
CAPRELLA EOUILIBRA
BIVALVIA
PLEURONECTIDAE
CLAUSIDAE _
ai.f.0
20.70
17.40
10.30
8.90
6.10
3.80
?.40
1 .90
1.40
1.40
1.40
.90
.90
.90
.90
.90
.90
.90
.90
.50
.50
.50
.50
.50
.50
.50
.50
.50
.50
PREY TAXA WITH FREO. OCCl/R, LESS THAN 5 AND NUMERICAL AND GRAVIMETRIC
COMPOSITION BOTH LESS THAN 1 ARE EXCLUDED FROM THE TABLE AND PLOT
(BUT NOT FROM CALCULATION OF DIVERSITY INDICES)
PERCENT DOMINANCE INDEX
SHANNON-WEINER DIVERSITY
EVENNESS INDEX
.00
.00
.00
.00
.00
.00
.00
.00
.00
154
-------
Table B-6. Prey composition (numerical and gravimetric composition) of
Pacific staghorn sculpin in Everett Bay, Washington, documented
by Conley (1977).
- L^OTOCOT TUS AP'«ATIJS
(PAC. STAGHODN
PI.
r-c
TF I
vnF> nF
FD1:< FILE IOFNT
(I.P.I.) TABLE
f, -> , STATION SLSTA
FPEO NUM.
OOF_C IT^" OCCllP COMP.
V* .10
ii'/arp 5 .,„
• ?0
o.Mnn, C3. >40
i_4T fOr-iy ^ = T^LL^TIJS 10
j*~lr\nf~r- • i '
^TOArrM
.'CTOfOTTtiC^r-'i-r^ ' • f- /
I'JV-'llJtlKit,. HJ|j^ _-
e *t if o T i^c. A - *
L**^l)rfl i * *»
:,rnc^i 14>A°
•I I 'i«,l-^ ^D -10
-a^^-^D. tn
;^^^Q4 »nu
lc;r|c -1 J,;.. CD. *7"
r T f-'po ^ Tp-. , ,- A/-J.I c *T.,^ 79.30
^'-i('-i>a(jl[_f.*Tlje; .
r Aoc.oi-pt: ar -,VI ,ca -- *
•^OPVTF<; HrxapfFons *^°
T n MC CD. ' «?0
.10
C-RAV.
COMp.
.10
.80
.50
.10
.10
45.00
.40
.60
?3.00
.10
2.90
1.00
3.00
.80
.10
PPFY PEPCENT
I.O.I. TOTAL IPI
" "
= = FV TA>A vITH KPFO. OCCUC. LES"; THAN S 'NO K'HME°ICAL ANO
ro.-onsT TIT. -^OTH L^S^ THAN 1 AP^ FxCLU.DED
("MT MOT FPOM C«l CPL4TIO-J OF DI»'
THE TABLE AND PLOT
DIVERSITY
1.08
1 .
.4?
.00
.00
.00
155
-------
INDEX OF RELflTIVE IMPORTANCE (I.R.I.) DIflGRfln
FROM FILE IDENT. 76-78. STflTION flLSTfl
8831022401 OLIGOCOI7US nflCULOSUS
TIOEPOOL SCULPIN
flOJUSTED SflnPLE SIZE = 512
60
60
100
80
100
120
140
160
160
CUnULRTIVE FREQUENCY OF OCCURRENCE
PPFY ITF«
OAMUAPIQE&
H*oP4CTICOl()a
ciP»i°Ef>iA
pnt vCNAiiT*
OfPTFRA
^rpTEA^
IIMIOFNTIFIED
CRIKTACE',
COTTIDAE
FPfO
OCCUR
53.93
14.77
1 ft. 0?
11.67
7.11
s. o«
1.71
2.73
ll95
1.17
.98
.19
.19
.39
NUM.
CO*P.
77.07
_1J.9«!
P4.30
1.77
1.57
1.09
.54
.19
1.45
5.79
.05
.11
.05
GPAV.
COMP.
73.46
.61
1.38
14.7?
.26
.59
.37
.30
1.0"
3.00
7.00
2.00
1.74
3.84
1.35
1.76
1.57
PRFY
I.P.I. '
7674.7
1755.9
199.1
740.0
15.9
7.4
5.2
4.4
\f ."
8.0
11.7
6.1
1.5
.9
.7
PERCENT
fOTAL IP1
54.6?
75.65
8-15
4.3?
4.90
.3?
.24
.15
.11
.09
.17
.38
.18
.78
.11
.01
.0?
.01
.01
PPRY T«xA «TTH FCTQ. OCCUR. I F5S _THAN 5 «Nn_MIIMEP IC«L_»NO Q.0.4" IME TBiT,_
cn»pn<;iiinN '>OT» i.tss THAN i AOE ExCLiiOEN run" THE TIRLE ANO PLOT "~
(BUT NOT FRO" TA| CIIL'TIOM OF niVFP^ITY TNOITFS)
PF.PCENT DOMINtNTE IMOFX
S^AKiNON-v'F INFO DIVERSITY
EVENNESS iwntj
.38
1.90
Fig. B-50. IRI prey spectrum of tidepool sculpin in littoral habitats
along the Strait of Juan de Fuca.
156
-------
Table B-7. Prey composition (numerical composition) of tidepool sculpin
at Port Renfrew, Vancouver Island, B.C., documented by Nakamura
(1971).
PREDATOR 8831032401 - OLIGOCOTTUS MACULOSUS
(TIOEPOOL SCuLPIN
INDEX or RELATIVE IMPORTANCE TABLE
FROM FILE IDENT. REF 68* STATION SLSTA
PREY ITEM
FREO NUM. GRAV. PREY PERCENT
OCCUR COMP. COMP. I.R.I. TOTAL IRI
OSTRACOOA
COPEPODA
MOLLUSCA
GAMMARIDEA
DECAPOD*
INSECTA
OSTEICMTHYES
ISOPOOA
ANNELIDA
CAPRELLIDEA
.70
61.40
.40
23.60
1.00
4.30
.40
3.50
4.30
.10
PPEY TAXA WITH FREO. OCCUR. LESS THAN 5 AND NUMERICAL AND GRAVIMETRIC
COMPOSITION BOTH LESS THAN i ARE EXCLUDED FROM THE TABLE AND PLOT
(BUT NOT FROM CALCULATION OF DIVERSITY INDICES)
PERCENT DOMINANCE INDEX
SHANNON-WEINEP DIVERSITY
EVENNESS INDEX
.44
1.67
.so
.00
.00
.00
.00
.00
.00
157
-------
a
i
a
s
o
lOOr
80
60
INDEX OF RELRTIVE IMPORTRNCE (I.R.I.) DIRGRRM
FROM FILE IDENT. 76-78. STRTION flLSTfl
8831022402 - OLIGOCOTTUS RIMENSIS
SfiDDLEBRCK SCULPIN
RDJUSTEO SRMPLE SIZE = 75
40
20
2 20
40
60
80
100
20
40
60
80
100
120
140
PREY !TCM
CUMULRTIVE FREQUENCY OF OCCURRENCE
FREO NUM. GRAV. PREY PERCENT
OCCUR COMP. COMP. I.R.I. TOTAL IRI
GAUMARIOEA
HARPACTICOIOA
SPWAFRIV'AT II1AE
POLYCHAFTA
CIOOIPEDIA .
FLABFLLIFFRA
ISOPODA /
CHL030PHYT-A/ _ _. -.
ARGHL IHEA
NATANTIA
COTTIDAF
56.00
3?. 00
??.67
4. 00
4.00.
?.67
1.33
1.33
1.33
1.33
^ 1.33
3fl 14
31.27
14.43
1.03
2.75
1 .03
.34
... .34
4.12
.34
.34
55.04
1.03
16.57
1 .44
.. .98
1 .44
1.92
7.68
.02
3.64
6.96_
"18.5
1033.7
702.7
9.9
1<(.9
6.6
3.0
10.7
5.=;
4.0
9.7
74.16
14.69
9.99
.14
.21
.09
.04
.15
.08
.06
.14
DPFY TAXA WITH FREO. OCCl'R. LES«; THAN S ANH NUMERICAL AND GRAVIMETRIC
_Cn-«POSITION_woTH LESS THAN ]_ARF ExCLMOFO FPOM_THE TABLE_ANO PL.OT
(RUT NOT FROM CA|_CULATIO" IF DIVERSITY INDICES)
PFRCFNT _OOMlMANiCE_ INOEX
"SHANNON-WFINEP DIVERSITY
EVENNESS
_
?.50
.54
?.35
.51
1.1 fl
.25
Fig. B-51. IRI prey spectrum of saddleback sculpin in littoral habitats along
the Strait of Juan de Fuca.
158
-------
INDEX OF RELRTIVE ItlPORTRNCE (I.R.I.) DIROfWI
FROM FILE IDENT. 76-78. STRTION RLSTR
lOOr
8831022403 - OLIGOCOTTUS SNYDERI
FLUFFY SCULPIN
flDJUSTED SfittPLE SIZE - '86
8
a.
CUMULRTIVE FREQUENCY OF OCCURRENCE
FPEO
PREY ITEM
GAMMSPTDEA
e;pt- AF_ROM AT I DAE
HARPACT ICOIOA
POLVCHAETA
..TANA1DACE-A
IPOTEIPSE
CIRRIPEDIA
P<;TPACODA
NE«FPTEA
CAPPELLIDEA
..S'PELUPAE
OCCUR
5«
?*•
17
1?
12
fl
5
^
3
?
1
.14
,74
.79
.79__
.14
.«!
.65
.49
.33
. 16
NUM.
CO
47
in
3
_3
2
3
1
1
4
MP.
.59
.39
.01
.46
.93-
.54
.00
.15
.69
.15
.62
GRAV.
COMP.
58
1?
15
1
7
1
1
.10
.51
.76
.64
.34_
.14
.14
.01
.00
.00
.75
PPEY
I.R.
6143
612
3?7
?44
67
78
18
5
5
5
. 6.
PERCENT
I. TOTAL IPI
.7
.5
.3
.-<
.ft
.3
.5
.9
.0
.?
81
R
4
3
1
.64
•14
.35
.25
.89
.05
.24
.07
• 08
.07
.08
PREY TAXA WITH FPEO. OCCUR. UFSS THAN 5 AND NUMERICAL AND GRAVIMETRIC
rOMPO'UTION HOTH..LtS.S.THAN 1 ARE EXCLUDED FPOM_THE TABLE..AND. PLQT_
(BUT NOT FROM CALCULATION OF
PFPCENT DOMINANCE IMDF.X
SHANNON-WFINEP DIVERSITY
EVENNESS INDEX
DIVERSITY INDICES)
.23
2.M
.60
.38
1.99
.46
.68
1.09
.25
Fig. B-52. IRI prey spectrum of fluffy sculpins from littoral habitats in
Strait of Juan de Fuca.
159
-------
In Nakamura's (1971) comparison of the food habits of Oligocottus
maculosus and (). snyderi at Port Renfrew, Vancouver Island, B.C., (). snyderi
was shown to feed much more upon gammarid amphipods than 0^ maculosus, while
polychaete annelids and isopods were of secondary importance (Table B-8).
Accordingly, harpacticoid copepods, which composed over 60% of the total
number of prey consumed by CK maculosus, composed less than 5% of the prey
consumed by (). snyderi.
Cabezon
Juvenile cabezon caught by beach seine at a cobble beach habitat (South
Beach) in northern Puget Sound had full or nearly full stomachs.
Oniscoidean isopods were the most important prey (55.6 percent of total IRI).
Various epibenthic decapods (41.0 percent) including a shrimp (Heptacarpus
stimpsoni), a crab (Cancer oregonensis), and amphipods (mostly Eusiroides sp«,
also Atylus sp. and Allorchestes sp.), and a parapagurid hermit crab (3.4
percent) were also included in the prey spectrum.
Cabezon from northeastern Guemes Island and Legoe Bay collections along
the eastern shoreline had consumed Dungeness crab, Cancer magister, shrimp
parts, and a rock.
O'Connel (1953) described the food habits of cabezon in California
throughout their life history. Based on both frequency of occurrence and
gravimetric composition, crustaceans (primarily shrimp, Spirontocaris sp.
and Hippolytidae, crabs, Cancer sp., Pugettia sp. and Grapsidae, and gammarid
amphipods) and fish (Cottidae, Gibbonsia sp. and Blennidae) were important
prey of juveniles (Tables 9a and lOa); crustaceans (Cancer sp., Pugettia sp.,
Scyra sp., Grapsidae) and molluscs (Haliotis sp., Acmaeidae) were important in
the diet of subadult (Tables 9b and lOb); and crustaceans (Cancer sp., Majidae,
Pugettia sp., Phyllolithodes sp., Scyra sp., Hemigrapsus sp., Pasurus sp.
Cryptolithodes sp., Idotea sp.), molluscs (Haliotis sp., Acmaeidae, Cephalopoda,
Mimulus sp., P'olyplacophora. Bivalvia) and fish (Sebastes sp., Citharichthys sp.,
Cottidae) were all important in the diets of adult cabezon (Tables 9c and lOc).
O'Connel (1953) also illustrated seasonal differences where, based on gravimetric
composition, crustaceans became more important than fish in the spring diet
spectra for juvenile cabezon; molluscs were important to subadult cabezon just
during spring; and fish and molluscs increased in proportional contribution
during winter and spring in the diet of adult cabezon. In Ouast's (1968)
analysis of food habits of kelp bed fishes, decapod crustaceans and ceaphalo-
pods (Theuthidida), predominated the diet of cabezon (b ased on frequency of
occurrence) while fish (Perciformes), unidentified algae, other crustaceans
and gastropods also occurred frequently (Table B-ll).
Tubenose Poacher
Beach seine collections in the Strait of Juan de Fuca (Twin Rivers and
Morse Creek) provided tubenose poacher stomach samples which illustrated
a very specialized diet oriented almost exclusively toward mysids (Fig. B-53) .
160
-------
Table B-8. Prey composition (numerical composition) of fluffy sculpin at
Port Renfrew, Vancouver Island, B.C., documented by Nakamura(197l).
PREDATOR 8631022*03 - OLIGOCOTTUS SNYDERI
(FLUFFY SCULPIN
INDEX OF RELATIVE IMPORTANCE d.R.I.I TABLE
FROM FILE IDENT. REF 68, STATION SLSTA
• «»••••••••*•*•«**•**»•**<>•»*»<
PREY ITEM
FREQ NUM.
OCCUR COMP,
GRAV. PREY
COMP. I.R.I.
PERCENT
TOTAL IRI
OSTRACOOA
COPEPOOA
MOLLUSCA
GAMMARIOEA
OECAPODA
INSECTA
ISOPODA
ANNELIDA
CAPRELLIDEA
~ .20
3.60
.60
70.00
.60
.60
11.80
12.20
.SO
PREY TAXA WITH FPEO. OCCUR. LESS THAN 5 AND NUMERICAL AND GRAVIMETRIC
COMPOSITION BOTH LESS THAN 1 ARE EXCLUDED FROM THE TABLE AND PLOT
(BUT NOT FROM CALCULATION OF DIVERSITY INDICES)
PERCENT DOMINANCE INDEX
SHANNON-WEINER DIVERSITY
EVENNESS INDEX
.52
.46
.46
.00
.00
.00
.00
• 00
.00
161
-------
Table B-9. Prey composition (frequency of occurrence and gravimentric
composition) for general prey categories consumed by juv-
enile (a), subadult (b), and adult (c) cabezon in central
California documented by Connell(1953).
PREDATOR 883t-;3101 - SCORPAENICHTHYS MARMORATuS
(CABEZON
INDEX or RELATIVE IMPORTANCE
-------
Table B-10. Prey composition (frequency of occurrence) for specific prey
categories consumed by juvenile (a), subadult (b), and adult
(c) cabezon in central California documented by Connell(1953),
•REOATOR 8831023101 - SCORPAENICHTHYS MARHORATMS
(CABEZON
INDEX OF RELATIVE IMPORTANCE (I.R.I.) TABLE
FROM FILE IOENT. REF 69. STATION SLSTA
»•••••*•*••••••••••••••»•••»•«**••••*•••••••
a. juvenile
PREY ITEM
FREO
OCCUR
NUM.
COMP.
GRAV.
COMP.
PREY
I.R.I.
PERCENT
TOTAL IRI
SPIRONTOCARIS SP.
CANCER SP.
OSTEICHTHYES
GAMMARIOEA
COTTIDAE
GIBBONSIA SP.
PUGETTIA SP.
BLENNIDAE
GRAPSIOAE
HIPPOLYTIDAE
COPEPOOA
42.86
17.14
14.29
14.29
5.71
5.71
?.86
2.86
2.86
2.86
2.86
PREY TAXA WITH FREO. OCCUR. LESS THAN 5 AND NUMERICAL AND GRAVIMETRIC
COMPOSITION BOTH LESS THAN 1 ARE EXCLUDED FROM THE TABLE AND PLOT
(BUT NOT FROM CALCULATION OF DIVERSITY INDICES)
PERCENT DOMINANCE INDEX
SHANNON-WEINER DIVERSITY
EVENNESS INDEX
.00
.00
.00
.00
.00
.00
b. subadult
PREY ITEM
FREO NUM. GRAV. PREY
OCCUR COMP. COMP. I.R.I.
.00
.00
.00
PERCENT
TOTAL IRI
CANCER SP.
PUGETTIA SP.
OSTEICHTHYES
SCYRA SP.
HALIOTIS SP.
GRAPSIDAE
ACMAEIDAE
le.ie
18.18
9.09
9.09
9.09
9.09
9.09
PREY TAXA WITH FREO. OCCUR. LESS THAN 5 AND NUMERICAL AND GRAVIMETRIC
COMPOSITION BOTH LESS THAN 1 ARE EXCLUDED FROM THE TABLE ANO PLOT
(BUT NOT FROM CALCULATION OF DIVERSITY INDICES)
PERCENT DOMINANCE INDEX
SHANNON-WEINEP DIVERSITY
EVENNESS INDEX
.00
.00
.00
.00
.00
.00
.00
.00
.00
163
-------
Table B-10 (continued).
. adult
PREY
ITEM
FREO
OCCUR
NUM.
COMP.
6RAV.
COMP.
PREY
I.R.I.
PERCENT
TOTAL IRI
CANCER SP.
MAJIDAE
PUGETTIA SP.
HALIOTIS SP.
ACMAEIOAE
PHYLLOLITHODES SP. _
SCYRA SP.
SEBASTES SP.
CEPHALOPODA
UNIDENTIFIED
MIMULUS SP.
OSTEICHTHYES
POLYPLACOPMORA
BIVALVIA
PAGURUS SP.
CITHARICHTHYS SP.
HEMI6RAPSUS SP.
COTTIOAE
CRYTOLITHOOES SP.
IDOTEA SP.
45.65
45.65
43.46
16.30
16.30
9.78
8.70
5.43
5.43
4.35
4.35
4.35
4.35
2.17
.09
1.09
1.09
.09
1.09
1.09
PREY TAXA WITH FREO. OCCUR. LESS THAN 5 AND NUMERICAL AND GRAVIMETRIC
COMPOSITION BOTH LESS THAN 1 ARE EXCLUDED FROM THE TABLE AND PLOT
(BUT NOT FROM CALCULATION OF DIVERSITY INDICES)
PERCENT DOMINANCE INDEX
SHANNON-WEINEP DIVERSITY
EVENNESS INDEX
.00
.00
.00
.00
.00
.00
.00
.00
.00
164
-------
Table B-ll. Prey composition (frequency of occurrence) of
southern California kelp beds documented by Quast(19oH>
8B31023101 - SCORPAtNICHTHYS MAPMORATMS
(CARE70N
IN1E*
F PELATIVE IMPORTANCE (I.P.I.) TARLF
FILE IOENT. REF S<3 . STATIO" 5LSTA
FPEO
OCCUR
NUM.
COMP.
GRAV.
COMP.
I.R.I,
PERCENT
TOTAL IRI
ALGAF
THEUTHIDIDA 69.00
as.oo
25.00
20.00
7.00
7.00
PRFY TAXA JTTH FPEO. OCCUR. LESS THAN 5 AND NUMERICAL AND GRAVIMETRIC
COMPOSITION "OTH LE = S THAN 1 ARE EXCLUDED 'FooM THE TARLE AND PLOT
(PUT NOT F90M CALCULATION OF DIVERSITY INDICES) " "
COIJSTACE4
PLFnCYfVA
"GASTROPODA
DOMINANCF [NOFX
SHA^j^JO^^-w(r IMF.D
INDEX
.00
.00
.00
.00
.00
.00
.00
.00
.00
165
-------
(X
>-
CO
z
o
100
80
60
40
20
2 20
40
INDEX OF RELRTIVE IMPORTRNCE (I.R.I.) DIRGRRM
FROM FILE IDENT. 76-78. STRTION RLSTR
8831081101 - PRLLRSINR BRRBRTR
TUBENOSE PORCHER
ROJUSTED SRMPLE SIZE 35
60
80
100
20
40
60
80
100
120
PREY ITEM
CUMULRTIVE FREQUENCY OF OCCURRENCE
FREQ NUM. C-RAV. PRFY PERCENT
OCCUR COUP. COMP. I.R.I. TOT4L IPI
PAMMARIDEA
CHWACEA
C-AMMABIOAE
MATANTIA
17.14
S.71
?.7)
- 5.7L.
94.07
1.34
.57
_3.63
«8.SO 13S84.6
?.2\ ISO. 9
1.1? e.f.
1.H3 13.7
6.04_ ._55.3-
98.99
.44
.10
_. .40
OBEY TAXA »ITH fPEO. nCCljR. LES1? THAN «» AND NUMERICAL ANH GOAylMETPIC
-COMPOSITION BOTH LESS THAN 1. APE EXCLUDED EROM THE TABLE AND .PLOT.
(RilT NOT rpox CA|CUL*TIO'J Of" DIVERSITY INDICES)
__
SHAMNON-UFINEP DIVERSITY
INDEX
.89 ,79_
.41 .70
.11 .30
.•99
.10
• 04
Fig. B-53. IRI prey spectra of tubenose poacher from shallow sublittoral
habitats in Strait of Juan de Fuca.
166
-------
Tadpole Sculpin
n rtions from both northern
Although they appeared in neritic (townet) co^e" originated only
Puget Sound and the Strait of Juan de Fuca, stomach conte dg and mysids
from collections in the Strait of Juan de Fuca. Ga»"*"a epibenthic feeding
were the prominent food organisms (Fig. B-54) suggesting an ep
behavior.
Pacific Spiny Lumpsucker
Beach seine collections at Cherry Point and Legoe Bay provided the few
Pacific spiny lumpsucker specimens for analysis of stomach Contents. Gammarid
amphipods supplied 56.1 percent of the total IRI, hyperiid amphipods, -">•*
percent. Caprellid amphipods (3.0 percent), valviferan isopods IJ.l percent;,
and cumaceans (0.6 percent) were incidental prey.
Sturgeon Poacher
Sturgeon poachers in the north Puget Sound collections originated from
collections at Birch Bay. The total IRI was rather evenly distributed among
cumaceans, gammarid amphipods, shrimp (Crangonidae and Penaeidae), and
harpacticoid copepods. Polychaetes and tanaids were also found in the
stomachs.
Along the Strait of Juan de Fuca, winter beach seine collections at
Beckett Point and West Beach furnished the greatest number of sturgeon
poachers for stomach analysis. The overall prey spectrum (Fig. B-55) was
divided among cumaceans (36.3 of total IRI), gammarid amphipods (29.6/.) ,
and harpacticoid copepods (22.9%) as primary prey organisms, and "angonid
shrimp (including Crangon alaskensis and C. stylirostris) as secondary prey.
Ribbon Snailfish
Beach seine and tidepool collections at Jamestown and Twin Rivers along
the Straits of Juan de Fuca produced stomach samples of ribbon snailtisn,
wherein over 94% of the total IRI was contributed by gammarid amphipods.
Sphaeromatid isopods (Gnorimosphaeroma oregonensis and Exosphaeroma amplicauaa;
and mysids provided the remaining 6% (Fig. B-56).
Tidepool Snailfish
Some tidepool snailfish from a beach seine collection at Birch Bay had
consumed principally gammarid amphipods (41.4 percent of total IRI), polychaetes
(39.8 percent) and valviferan isopods (15.4 percent), with shrimp (Penaeidae)
providing a small contribution (3.4 percent).
intertidal th^ Strait' tidepool snailfish were the most common snailfish in the
Point and si' p*""8' and were regularly collected at Morse Creek, Observatory
' AS i? the C3Se °f the ribb°n snailfish, gammarid
woT ° I**** ^^ IRI' Id°te±d "opods^ncluding
montereyensis) and harpacticoid
167
-------
INDEX OF RELflTIVE IHPORTHNCE (I.R.I.) OlflGRRM
FROM FILE IDENT. 76-78. STflTION PLSTfl
PREDHTOR 8831070101 - PSYCHROLUTES PRRflDOXUS
(TflDPOLE SCULPIN 1 flOJUSTED SHMPLE SIZE = 12
100
80
60
2
O
£
§
fe
s
£
1
s
§
8
Q-
§
t—
u
Q-
40
20
0
20
40
60
80
100
— 1
V
•0 tJ
s . 5 £
•° S e S
•S « 61!
g 5 S g
g ^ nt -o
I III
1 1 1 1 1 1
0 20 40 60 80 100 12
CUMULflTIVE FREQUENCY OF OCCURRENCE
OS.fi TTFM
MYCJHACEA
PPHAEPOMATIOAE
I'WI DFNT IF ICO
FREO
occu"
SO. 00
33.33
16.67
P. 33
NU".
COMP.
37. SO
50.00
8.33
4.17
GRAV.
COMP.
58.47
37.04
3.37
1.12
PPF.Y
I.R.I.
™l:;
44.]
PERCENT
TOTAL IRI
60.44
36. S4
2*46
• 56
PPFY TA^»_wTTH_FPEO^_OCCl!P. LFSS_THAN 5 AND NUMERICAL ANO GRAVIMETRIC
ch'Mposifioiii ROTH LESS" THAN i" ARE EXCLUDED FQOM THE TABLE AND PLOT
('BUT NOT FROM CAl.CUL'TION OF DIVERSITY INDICES)
PEOCFNT DOMINANCE INDEX
SMANNON-WEIMFO DIVERSITY
EVENMFSS INOE«
.40 ,4R
1.5? 1.22
.76 .61
• 50
1.14
.57
Fig. B-54. IRI prey spectrum of tadpole sculpins in neritic waters along
Strait of Juan de Fuca.
168
-------
INDEX OF RELRTIVE IMPORTHNCE (I.R.I.) DIRORRM
FROM FILE IDENT. 76-78. STflTION RLSTR
8831080802 - ROONUS RCIPENSERINUS
STURGEON PORCHER
1QO RDJUSTEO SfittPLE SIZE = 82
80
60
40
8 20
100
CJ 4J -o « efl n) T-(
« U Qi IH E a.
« «a o M a x rn e -H ••-»
Z H PL. u w E C 3 CQ 3C
50
100
150
200
250
300
CUMULATIVE FREQUENCY OF OCCURRENCE
oREr ITEM
f, 4«M4RIDE4
CU"ACEA
H4CD4CT ICOID4
GAMMAPinAE
MATAMT1A
T4^ AICiACEA
DHL YrnA£T4
ro»Nc,oN]B4f
<;P»-AFOO^AT IDAE
WYC In A TEA
^*> TDACQOA
H'llnENTIFIED
RTV4L VI A
_HI_P£nLYT IOAT
FREO NUM.
OCCUR COMP.
51.22 17.
49.7B_..30.
3?. 93 43.
?.n5 ?.
19.51 .
13.41 1.
13.41
__ 13. 4J .
12. ?0
10.9S
7 T?
' . J t. ^ .
7.->?
ft. in
ft. 10
33
4S_.
31
68
92
53
62
6B . .
49
30
09
33 ~
15
21
GRAV.
COMP.
17. IS
20.19
4.13
6.27
PREY PERCENT
I.R.I. TOTAL IRI
1765.9
2471.6
1562.?
?51.3
.,8.68 1B7.4
1.74
3.10
29.58
.41
i.as
• Oft
~.93
.19
_?l64
43.X
50.0
406.0
11.0
?3.9
I y
- 1 . C. _
9.?
2.0
. L7.4
?5.91
36.27
?2.93
3.69
_.2.75 —
.64
.73
. 5.96-_
.16
.35
. n ?
• V C.
.13
.03
.26
OTHPf?;«.°TC"h'* ^^ ™ftN S *Nn NUMERICAL AND GRAVIMETRIC
C», rt), AT!HM or ^E fXCLL)OED FOPM THE TABLE ANO PLOT
LAICULATJON OF OIVFRSITY INDICES) ~ '
Fig. B-55
•
PFDCE'JT OnMlMA'.'Cr
SHANHON-WFIMFP
EVEi-wF. SS INOE.
.31
?.09
.44
•I7
3.0?
.64
.26
?.29
169
-------
INOEX OF RELflTIVE IMPORTflNCE (I.R.I.) DIflGRRM
FROM FILE IDENT. 76-78. STflTION RLSTfi
8831090806
lOOr
LIPRRIS CrCLOPUS
RIBBON SNRILFISH
flDJUSTEO SRMPLE SIZE 39
80 •
V 60
CD
ION BY HEIGHT PCT. COMPOSITION
-p. N) N> *.
O O O O O
§ 60
H
\ 1 1
11
n
•u
•H a>
(U «> 4-t PI
80
-O
-------
INDEX OF RELRTIVE IMPORTRNCE (I.R.I.) DIRORRH
FROM FILE IDENT. 76-78. STRTION RLSTR
8831090810 - LIPRRIS FLORHE
TIOEPOOL SNRILFISH
y
CQ
CC
>_
CO
s
1—
§
0
k-
a
1—
LJ
3
£
2
O
g
Q_
z:
o
<_>
t—
o
**-
PREY
Oft WM ABIDE A
_I On T t 1 0 ftF
^P^AfftOMAj I n A £"
HADP6CTICOIDA
C AOPri I T nr- A
-w r C-L_l_iUt- *^
H]DP(^l_YT ID6F
IMCFCTA
L'NIDENTIFIEO
NATAMT 14
°OFV TOIA WI
CnMDQMTiorg
I^UT MOT FPO
100
80
60
40
2C
f
L
20
40
60
80
100
RD JUSTED SRMPLE SIZE = 87
.
•
"^LTtij
.
(0 CO
TS -a a) i
•H TH eg to 1
HE TABLE AND PLOT
-EvE'.'jEss'
NCF IMOEX
DIVERSITY
.49 .4,7
1.65 1.79
• 3S.._ ,38_
.89
.43
.09.
B-57
de^ucf Sna±lfish in littoral habitats
171
-------
Shiner Perch
Shiner perch were relatively common in the nearshore beach seine catches
in northern Puget Sound, especially at Deadman and Westcott bays during summer;
they were also caught in the townet at Birch Bay, Cherry Point, and Burrows
Island. Prey composition was relatively equally divided between a number of
epibenthic organisms (Fig. B-58), gammarid amphipods (38.6 percent of total
IRI), cumaceans (29.2 percent), and polychaetes (22.2 percent) with caprellid
amphipods making a lesser congribution (8.0 percent).
Shiner perch also ranked high among the most abundant species in the
collections along the eastern shoreline, being especially common at the
Cherry Point (cobble habitat), Padilla Bay (mud/eelgrass), and Legoe Bay
(gravel) sites. Compared to the San Juan Islands samples, the prey composition
from these collections was considerably less diverse (H* = 2.61 for abundance
and H' = 2.60 for biomass, versus H1 = 1.53 for abundance and H' = 1.26 for
biomass) and was dominated by gammarid amphipods (95.6 percent of total IRI)
with only minor contributions by calanoid copepods and isopods (Fig. B-59).
Shiner perch was one of the principal schooling nearshore fishes
characterizing the eastern MESA sampling sites along the Strait of Juan de
Fuca, especially at Beckett Point and Jamestown. The diverse IRI prey spec-
trum was composed of gammarid amphipods (47% of total IRI), cumaceans, harpac-
ticoid copepods, tanaids, sphaeromatid isopods (including Gnorimosphaeroma
oregonensis and Exosphaeroma amplicauda), algae, and calanoid copepods (Fig.
B-60).
DeMartini (1969) listed bivalve molluscs, gammarid amphipods, tanaids,
cumaceans, polychaete annelids and ostracods as the principal prey organisms of
shiner perch.
Weller's (1975) analysis of shiner perch food habits in Anaheim Bay,
California, indicated that unidentified eggs dominated the prey biomass during
all seasons (Table B-12a-d) although topsmelt (Atherinops affinis) were
somewhat important in the spring, insects and mussels (Mytilus edulis)
appeared in the summer and fall diets and mussels, polychaetes, gastropods and
topsmelt occurred during the winter.
The studies of Bane and Robinson (1970) in upper Newport Bay, California
indicated only Potoamogetonaceae plants (includes eelgrass, Zostera marina),
crustaceans and rocks as the principal prey of shiner perch; this is based,
however, only on frequency of occurrence data (Table B-13).
Striped Seaperch
Striped seaperch from northern Puget Sound (Deadman Bay, Guemes Island
and Cherry Point) had a prey composition composed almost entirely of epibenthic
or benthic crustaceans—gammarid amphipods, valviferan and flabelliferan
isopods, crabs and shrimp, while in the Strait of Juan de Fuca (Beckett Point,
Twin Rivers, and Morse Creek) over 90% of the striped seaperch prey spectrum
was made up of gammarid amphipods, supplemented by sphaeromatid (Gnorimosphaeroma
oregonensis) and idoteid (Synidotea nodulosa) isopods.
172
-------
100
INDEX OF RELflTIVE IMPORTRNCE (I.R.I.) DIHGRRM
FROM FILE IDENT. N POSO. STRTION RLSTH
PREORTOR 8835600201 - CYMHTOGflSTER RGGREGflTfl
(SHINER PERCH ) flDJUSTEO SflMPLE SIZE - 31
80 r-
60
" 40
-
=i- 4p-
o
fe
o
o
40 h
60 r
80 h
100L
QJ « efl eg CD
w-i -H V *O I
1-1 -o u « « o «
^ 0) « T) -H D. "B
i-t a-a o > o o
01 -H ft O.f-1 VJ O.
£ b m ai « O
20
40
60
80
100
120
140
160
180
CUMULflTIVE FREQUENCY OF OCCURRENCE
°RFY ITF"
r-A"'J«p IO(£A
POI vfMir TA
rt|^*^fa —
TAnnFLL 1 DE A
^t "P^LLTTrc A
CloolPFOIA
TA^AJOACE A " — — — - - —
P I V A L V 1 A - .
GASTROPODA
DFCAPnoA-ypacnYUPA
"Cp^;? -'i;;/°r«: "EC,,*. LE
FRFO
OCCUR
55.00
17.00
?*.oo
?1.00
6.00"
6.00
- 6.00" '
1.00
1.00"
1.00
1 • 00 -
:«<; THAN
Nl.1'1 .
COHP.
38.82
2.17
16.30
4.31
" 2.90
1 .60
'• .43
10.31
1.11 —
1 .2?
.05-
5 AND
GRAV.
COMP.
?9.10
34.10
16.81
12.09
.95
.03
.03
.48
"4.35
.02
1.2T
NUMER
PREY
I. a. i.
18585.6
1 160.6
1180.9
177.?
?3.1
9.0
2.«
12.4
— 16.4
3.7
— ~ 3.9 '
IC»L ANn
PEBLtNT
TOTAL IRl
96.10
5.40
6.40 "" ~
1.70
.10
.00
.00
.20
" .10
.00
.00"
GRAVIMETRIC
AN ' *RE EKCLUOEO FoQM THE TABLE ANO CLOT
-
Pig. B-58.
."•IT HOT rpo» CALCULATION OF-D1VERSITY INDITES.
^"CFNT-OOMlNA.jCF INDFX -,„— „
'•"A'.NO'J-WFINFP DIVFC^ITv •3° "?5
tvEM.j£<;c TNf1F. UIVtP^ITr ??1
.6? .65
IRI prey
.75"
.80
.29
173
-------
a
i
£
g
INDEX OF RELRTIVE INPORTRNCE (I.R.I.) OlflORfiH
FROM FILE IDENT. HH BS. STRTION flLL
PREORTOR 8835600201 - CYMflTOORSTER flOOREGflTfl
(SHINER PERCH I flDJUSTED SflMPLE SIZE = SI
100
80
60
e 40
8
fc
3 20
2 20
40
60
80
100
10
20
30
40
SO
60
70
80
90
CUMULflTIVE FREQUENCY OF OCCURRENCE
PREY ITEM
fiAMMARIOEA
CALANOIDA
ISOPOOA
CRUSTACEA
ANTHOZOA
PACURIDAE
FREO
OCCUR
53.00
14.00
12.00
4.00
?.oo
2.00
NUM.
CO"P.
ft7 fl PLOT
_(Ry_T NOT_FROM_CAl CULAjriON_OF_gIj/ERSJTY INDICES)
PERCENT DOMINANCE INDEX
SHANNON-WEINER. DIVERSITY
EVENNESS 'INDEX
.52
.63
l.?5_ 1.11
.<•<» .43
.86
.45
.22
Fig. B-59. IRI prey spectrum of shiner perch from shallow sublittoral habitats
along the eastern shoreline of northern Puget Sound.
174
-------
INDEX OF RELHTIVE IMPORTRNCE (I.R.I.) D1RORRM
FROM FILE IDENT. 76-78. STRTION RLSTR
8835600201 - CYHRTOORSTER ROGREGRTR
SHINER PERCH
100
80
60
40
20
2 20
40
8
a.
60
80
100
RDJUSTED SRttPLE SIZE = 168
Q
•o
•H
o
20
40
60
80
100
120
140
CUMULflTIVE FREQUENCY OF OCCURRENCE
FREQ NUM. GRAV. PPEY PERCENT
r,Au
PPF.Y ITFM
M40IOEA
OCCUR
38
.A9
ClJ"ACEA 1°.45
SPh
TAN
4rpOMAj 10AF
SIDACEA
HAODACTICOIHA
irn
"01
GA"
y Y<=
1 11. O
TAL
K. A T
r A i
1 01
TFIDAE
YCHAFTA
•••4DJ04E
TDACFA
TD I CHA[_ES
4 • 1 0 I 0 A
AMTIA
L I AN Ac S I Pi AF
11
1 1
1 1
7
ft
=;
4
4
3
1
.10
.90
.11
.74
.55
.Tft
.7ft
.17
.57
.19
.60
COMP.
10.49
77.31
3.61
14.09
71.70
.45
.32
5.9ft
1.35
.97
10.P5.
.05
.03
COMP.
24
9
10
7
2
2
3
7
2
17
1
1
7
.43
.50
.07
.45
.99
.18
.75
.88
.77
.19
.24
.14
.46
I.R.
1151
e.79
179
256
101
2.0
26
74
19
75
41
1
4
I. TOTAL IRI
.1 44
.3 ~t
.1
.4
.9
.1
.ft
.2
.ft
.7
. 0
.4
.5
•2
5
8
9
2
2
.1
.51
• 38 _
.90
.45
.95 ..
.67
.88
.44
.65
.49
.35_ _
.05
.15
A wITM FREO. TCr,,
C4|
LESS THAN! ; AND NUMERICAL AND GRAVIMETRIC
1 ARF EXCLUDED FopM THE TABLE AND PLOT
.18
7.85
.58
.13
3.34
.27
2.42
.49
Fig. B 60. IRI prey spectrum of shiner perch in the Strait of Juan de Fuca.
175
-------
Table B-12
PREDATOR
Prey composition (gravimetric composition) of shiner perch
during spring (a), summer (b), fall (c), and winter (d) in
Anaheim Bay, California, documented by Weller(1975).
- CY 'ATO'jASTFP
(SHINFR PERCH
IMOE* "F PF.LATIVF IMPORTANCE (I.P.I.) TABLE
FRO" FII_F IDENT. PEF 51. STATIOM SL5TA
ITEM
FPFO NUM. GPAV. POFY
OCCUR COMP. COMP. I.R.I
PERCENT
TOTAL IRl
FMTPROMOQPH4
Ch| OaOPHYTO
TEGULA SP.
r-4CT
MLVA
CADOF
OL'VCLLA S°.
ATHERINOPS AFFINIS
OCYEwaTa-CA0
i| lit; FD'jl, IS
1.70
1.10
16.90
5.00
1.30
1.10
3.70
TAXA WITH FOF.Q. OCCUR. LES1^ THSN S AND NUMflCAL ANO
lnr. MOTH LE<=<: T^AN 1 ARF EXCLUDED FOP" THE TABLE
(»I|T ^|OT F9OM C A|_ C.IJL AT I OM OF OI'/ERSITY INDICES)
.00
.00
.00
C JOTEPA
-WFINFO DIVERSITY
PLOT
.00
.00
.00
FOFO NUM. G"AV. POEY PERCENT
OCC'IR COMP. COMP. I.R.I. TOTAL IRI
r'apoFLL IDEA
TEGULA AP .
COPFPOD4
4MPHIPO04
ui.yA so.
6.70
5.30
PPFY T/i»a WITH FDFO. OCCll=. LESS THftN R ANO NUMERICAL ANO GPAVluETRlC
COMPOS I T tn.xi ^tOTH LESS TH4N 1 APF PxCLliOEt' FPOM THE TABLE ANQ PLOT
(-?IIT MOT FQOV CAI CULATION OF DIVERSITY
PERCENT OOMIMA'JCF INDEX
FlNFo DIVERSITY
TNOtX
.00
.00
.00
.as
.54
.00
.00
.00
176
-------
Table B-12 (continued).
G4Tfl
PERCH
OF =>EL&TIVF Iv = ORTA-iCF (I.O.I.) TAPl.F
M riLc I^'NT. RrF CT. c,TATlON SLSTA
c i. if * I T F •
F0£0 NUM. GPAV. PREY PERCENT
OCCUR COMC. COMP. I.P.I. TOTAL IPl
1 <; I r- a r F A
PLFOTYK •JiTa-CA0I
r>i I rjrMT IF I n Fr,r
"
VT ! i MS FIMIL I ^
1.70
? • 30
1 •hi
CDCY TA«a «ITH FPEO. OCCl"3. LFS^ THIN 5 AND NUMERICAL AND GRAVIMETPlC
CO"PO=;ITIO'j BOTH LE"5? TH&N 1 ARF E'CLUPEO F^O" THE TABLF AND PLOT
NOT FPOM CALCULATION OF DIVERSITY
^ •-• A f i* '0* J - V ^ JK'PP DIV^D<-ITY .00
,. ,r1n FPFr) NUM.
P°EY ITFu OCCUR CO'
-------
Table B-13. Prey composition (frequency of occurrence) of shiner perch
in upper Newport Bay, California, documented by Bane and
Robinson(1970).
(SHIMEP PEPCH
INDEX OF RELATIVE IMPORTANCE (I.D.I.) TAP.LF
rpnM fiLf IOENT. PEE Si., STATIOM SL5TA
PPFy
FOFQ NUM.
OCCUR COMP.
GRAV.
COMP.
POFY
I.P.I,
PFPCENT
TOTAL IPI
POC
CHI. O°OOHYTA
fi * T E I C H T H V E S
IDA
6=5.00
s^.on
si.no
TAVA WITH FRFO. OCCIJP. LFS^ THAM 5 AiMf) NUMEPICAI. ANH GRAVIMETRIC
ROTH LF.<;S THAN i APE EXCLUDED FRO^ THE TAHLE ANH PLOT
FPOU ("/II_CUI_ATIOM OF DIVERSITY INDICES)
PERCENT OOMlMANCF
EINFR DIVERSITY
INOKX
.00
.00
.00
.00
.00
.00
.00
.00
.00
178
-------
DeMartini's (1969) analysis of the comparative feeding mechanism
morphology among the surfperches indicated that bivalve molluscs, acmaeid
limpets, the shrimp, Callianassa californiensis, isopods, gammarid amphipods,
gastropods (especially Thais sp.) and caridean crustaceans were important
prey of striped seaperch.
Gnose's (1967) detailed study of striped seaperch in Yaquina Bay, Oregon,
indicated that the gammarid amphipods Amphithoe sp. and Anisogammarus sp.
comprised the most frequently eacCn prey item (Table B-14); mussels, barnacles,
chironomid insects and isopods (Idotea sp.) were of secondary importance.
Alevizon (1975) did an extensive comparative study of striped seaperch feeding
ecology in southern California. He found that, on the basis of prey biomass,
gammarids, polychaete annelids, caridean crustaceans, caprellid amphipods and
isopods were equally important at Santa Cruz Island (Table B-15a) while just
gammarid and caprellid amphipods and caridean crustaceans were of importance
to fish collected along the Santa Barbara shoreline (Table B-15b).
Pile Perch
Pile perch collected in the vicinity of Guemes Island and Cherry Point had
consumed mostly valviferan isopods (73.1 percent of the total IRI), bivalves
(10.5 percent), crabs (9.7 percent), and gammarid amphipods (4.5 percent).
Those collected along the Strait of Juan de Fuca, however, had consumed
gastropods (32.1% of the total IRI), pagurid crabs (Pagurus beringanus, P_.
granosimanus, P_. hirsutiusculus; 22.6%), gammarid amphipods, (13.6%), brachyuran
crabs, (11.5%), sphaeromatid isopods, (2.6%), valviferan isopods (5.9%) and
tanaids, (2.8%).
Pagurid crabs, fissurellid and acmaeid limpets, the bivalves Pododesmus sp.,
Mytilus sp. and Hinnites sp. and the gastropod Thais sp. were listed as
principal prey of pile perch by DeMartini (1969).
Wares (1968) has provided an extensive analysis of prey composition, using
frequency of occurrence and estimated percent volume, of pile perch in three
regions of Yaquina Bay, Oregon. In general, barnacles (Balanus sp.), mussels
(Mytilus sp.), crabs (Cancer magister, jC. productus, and C^. oregonensis) Other
bivalves (Clinocardium sp., Prototheca sp.) and shrimp (Upogebia sp.) were the
prevalent food organisms. When examining variations in prey composition by
seasons, crabs, particularly Cancer magister, appeared predominantly in the
spring while barnacles and mussels comprised the greatest proportion of the
diet during the rest of the year. In comparing the three regions of the bay
(upper, mid and lower) there were no consistent trends although decapods
appeared to be most important in the diet of pile perch occupying the lower
bay and bivalves other than mussels appeared predominantly in fish from the
upper bay. In general, however, there was no change in feeding ecology, as
all prey were epibenthic or benthic organisms which were "picked" from the
bottom.
Quast's (1968) documentation of the food habits of pile perch in southern
California kelp beds indicated that decapod crustaceans, bivalve molluscs
and ophiuroids were the principal prey of all size classes while only
gastropods entered significantly into the prey spectra of fish 200-299 mm in
length (Table B-16a & b).
179
-------
Table B-14. Prey composition (frequency of occurrence) of striped seaperch
in Yaquina Bay, Oregon, documented by Gnose(1967).
PREDATOR
LATE"ALIS
(STRIPED
F RELATIVE IMPOPTANCE (I.o.I.) TARLE
FPOM FILE IOENT. REF S7. STATION SLSTA
POEY ITEM
FPEO NUM. GRAV. PREY
OCCUR COMP. COMP. I.R.I,
PERCENT
TOTAL IRI
4MPHJTHOE S°.
ANISOGAMMARUS SP.
MYTH. us s°.
RAI.AMIIS SP.
OIPTFRA-CHI=>ONOMIPAE
SP.
SP.
MEMBRANIPORA SP.
IIPOIFBIA SP.
POL YCHAFTA
lIMTOFNTIFIEO
i ITTORIMA SP
Cl.!»inCAOOIIIM
PSTOACODA
COLEOPTERA
"AMPHISSA SP.
ACMAFIOAE
BUCCINUM SP.
~T~ACUMA "SP.
SILIQUA AP.
?o.so
9.40
7.70
1.AO
3.40
T.40
?.60
1 .70
1 .70
.90
.90
CRFY TAXA WITH FOEQ. OCCll^. LESS THAN 5 ANfl NUMERICAL ANO
COMPOSITION POTH LESS THAN 1 ARF ExCLUOEO FPOM THE TARLE AND PLOT
(P-IlT NOT FROM CAICULATION OF DIVERSITY INOICFS)
PERCENT nnMlMlNCF INOE»
SHANNON-WFINFP DIVERSITY
.00
.00
.no
.00
.00
.00
.00
.on
.00
180
-------
Table B-15. Prey composition (frequency of occurrence and gravimetric
compsoition) of striped seaperch at Santa Cruz (a) and Santa
Barbara (b), California, documented by Alevizon(1975).
(STPIPF.O SEAPEPCH
OF* nF PELATIVF
FQ STATION SLSTA
PPFY TTF«
r-ACTPODIQA
FCI-IMOIOEA
nFCApnoA-PLFOCYE"ATC
GALATHEIDAE
nFCAPr)r)A-PLFr>rvEMATA
ArwAFIDAE
Ppl_YDLAl~nPHOC4
PI V/ALVI A
PQTF K^T-oFc;
ppi-lnppinEA
FPFO MI«. G"AV. PPEY
OCCHP CriMp. COMP. I.P.I.
7^.00
?1 .<3(i
19. «0
1P.SO
1?.SO
1P.SO
Q.'iO
3. in
3. 10
•». 10
PERCENT
TOTAL IPI
17.00
?1 .00
10.00
I'..00
7.00
IP.00
DDF i Till -I-TH FOFQ. OCCi:». LF9q THAN S ANn NUMERICAL ANO GP»VI ME TRIC
ri"0l<;i T ION HO™ Lt^S THAN ] AP>- F»CLHOFO Foo" THE TABLE AMP PLOT
(SiiT NOT FPOM CALdJi.ATIOM OF OWEP^ITY IN.DICES)
<;"4NNOM-JF IKFP DlvFPSITY
FVr .•j"'-IS INOf»
.no
.oc
.00
2.35
.91
.00
.00
.00
b.
FPFO NUM.
OCCMP CO"P.
GPAV. PPEY PEPCENT
COMP. I.P.I. TOTAL IPI
PI Vi| VIA
IIMHFNT IF IEP
_PPhJliOOl,',F A
C.A"MAoir,F4
PLFOCYf'l,T 'iOT
f^. OCfli". L'lSe; THAN = AND *iUMEDIC*L "NO
LECS Tt-aN 1 4 u F. ^xTLUDEO FPOM THE TABLE ANO PLOT
riji.4TIOf OF DIvfPSITV I'.OirES)
DIVF.PSITY
.00
.no
.00
.93
.00
.00
.00
181
-------
Table B-16. Prey composition (frequency of occurrence) of pile perch
100-199mm (a) and 200-299mm long (b) in southern California
kelp beds documented by Quast(1968).
- RHACOCHILUS VACCA
(PILE PERCH
INDEX nF RELATIVE IMPORTANCE (I.P.I.) TAfiLE
FPriM FIl.E [DENT. REF ^9. STATION'
a.
PREY ITE"
FPEQ NUM. GPAV. PREY
OCCUR COMP. COMP. I.R.I,
PERCENT
TOTAL IRI
DECAPODA-PLEOC'-'E'-'ATA
BIv/ALVIA
PLEOCYE'iATi-CAPIOfa
RPYO?OA(ECTOPOOCTA)
_IOrTEA REStCATA
"GASTROPODA
ALGAE
.b-
68.00
6«.on
19.00
10.00
.00
.00
.50
.sn
.so
PPFY TAXA WITH FPEQ. OCCllW. LES^ THAN S AND NUMERICAL ANO GRAVIMETRIC
COMPOSITION ROTH LF«;S THAM 1 ARE EXCLUDED FPOM THE TAflLE AND PLOT
(BUT NOT FROM CALCULATION of DIVERSITY INDICES)
PERCENT DOMINANCE
SHANNON-WEIMER DIVERSITY
EVEN'MESS INDEX
.00
.00
.00
.00
.00
.00
.00
.00
.00
PQF.Y ITP>
FPEO
OCCUR
NUM.
COMP.
GRAV.
COMP.
PPEY
I.R.I.
PERCENT
TOTAL IRI
DECAPODA-PLEOCvEMATA
PIVALVIA
GASTROPODA
"OPPIIIROIDEA
8PY070A (ECTOPROCTA)
UNIDENTIFIED ALGAE
GAMMARIDEA
PLEOCYEMATA-CAPIDFA
IOOTEA
CAPOIIOAE
PAGURIOAF
47.00
44. 00
PS.OO
14.00
6.00
S.OO
'5.00
5.00
.50
DONAX SP.
PDFY TAXA vdTH FPFO. OCCl'O. LESQ THAN S AND NUMERICAL AND GPAvIMETRlC
N POTH LESS THAN i APE EXCLUDF.D FPOM T^E TABLE AND PLOT
NOT FPOM CALCULATION OF DIVERSITY INDICES)
PERCENT DOMINANCE. INDEX
SHANNON-WFIMED DIVERSITY
EVENNESS INDFX
.00
.00
.00
.00
.00
.00
.00
.00
.00
182
-------
Redtail Surfperch
Redtail surfperch occurred abundantly only along the western Strait of
Juan de Fuca (Twin Rivers and Hydaka Beach). Over 70% of the prey spectrum
was gammarid amphipods. Mysids (including Neomysis awatschensis),
sphaeromatid isopods (including Gnorimosphaeroma oregonensis and Exosphaeroma
sp.), flabelliferan isopods, idoteid isopods (including Idotea resecata and I.
wosnesenski), and polychaetes were secondary prey (Fig. B-61).
Snake Prickleback
Stomach samples from snake prickleback from northern Puget Sound
characterized this species as principally a benthic feeder. Bivalves
composed 48.7 percent of the total IRI, tanaids and polychaetes both accounted
for 21.2 percent, and gammarids amphipods contributed 7.3 percent.
Oligochaetes accounted for 84.4 percent of the total IRI; gammarid
amphipods, 11.0 percent: and polychaetes, 4.6 percent, in stomachs from fish
collected in the mud/eelgrass habitat (Fidalgo Bay) near Anacortes.
Gammarid amphipods and harpacticoid copepods were the major prey, based
on numbers, and polychaete annelids provided significant contributions to the
prey biomass of snake prickleback collected in nearshore habitats of Kodiak
Island, Alaska (Harris and Hartt 1977).
High Cockscomb
The most ubiquitous prickleback in littoral habitats along the Strait,
A. purpurescens was a predominant member of the intertidal assemblage at
Slip Point, Observatory Point, Twin Rivers, and Morse Creek. Nemertean worms,
gammarid amphipods, and polychaete annelids predominated in the overall prey
spectrum (Fig. B-62).
Based on frequency of occurrence, gammarid amphipods, polychaete annelids
and gastropod molluscs predominated in the diet of high cockscomb examined from
San Simeon, California by Barton (1974) (Table B-17).
Based on frequency of occurrence, Peppar (1965) assessed the diet of
high cockscomb collected at Second Narrows, Burrard Inlet, British Columbia.
He found algae, polychaete annelids, gammarid amphipods and flatworms to be
the most commonly occurring food items (Table B-18).
Black Prickleback
Almost three-quarters of the total prey IRI (Fig. B-63) of black
pricklebacks collected during the MESA studies in the Strait were gammarid
amphipods. Sabellarid and polychaete worms and several algae were also
important.
Anomuran crabs, gammarid amphipods and the alga, Ulva sp. were the
major constituents, based on frequency of occurrence, of the diet of black
prickleback at San Simeon, California (Barton 1973; Table B-19).
183
-------
100 r
80
60
40
INDEX OF RELRTIVE IMPORTANCE (I.R.I.) DlflGRRfl
FROM FILE IDENT. 76-78, STflTION PLSTfl
8835600701 flMPHISTICUS RMODOTERUS
REDTfllL SURFPERCH
flOJUSTED SflMPLE SIZE 142
20
20
40
60
80
100
oc o» ffl
C O T3
ra >, c
I-H , -H > QJ 4)
it —in ^H en u
—' O > nl C VI
U. 0. Z > « O
50
100
150
200
250
JTFM
CUhULflTIVE FREQUENCY OF OCCURRENCE
&PAV, PREY PERCENT
COUP. I.P.I. TOTAL IRI
OCCUR
NUM.
CO«(P.
<•]. ?5 ?5.43 ?0.f>0
?
9.7
?5.3
'>.'•
_ 1.0
3.7
NUMERICAL AMD
rjow T ^!a^J
-«F [Mf p
INOr
.1?
3.M
.7<4
?.3S
.51
Fig. B-61. IRI prey spectrum of redtail surfperch in shallow sublittoral
habitats along the Strait of Juan de Fuca.
184
-------
INDEX OF RELRTIVE IMPORTHNCE 11.R.I.) OlfiORWI
FROM FILE IOENT. 76-78. STRHON flLSTH
8842120402 - HNOPLHRCHUS PURPURESCENS
HIGH COCKSCOMB
BOJUSTED SflMPLE SIZE = 273
PCT. COMPOSITION BY HEIGHT PCT. COMPOSITION BY flBUNOSNCE
SaasSoSSSSS
; 3
! 1 1
0 20 40 60 80
CUMULRTIVE FREQUENCY
FBEO NUM. GPAV.
PaFY 1TE" OCCUR COMP. COHP.
HFUEBTEA 34.07 ll.BT 25.50
_r.AM-iBl-)EA 3?.«.0 16. ?» 6.72
POLYCMA^TA 27.71 6.97 20.86
HAOPACT1COIOA 8.79 4.19 ,0«
_LiHIPFNTIFIED fc.9ft 1.99 7.IQ
PHnnoPHYTA «,.?3 1.90 ?.02
CM|_nonPHYT4 4.7>> 1.85 3.0.1
(!4«tDnPnDA 4.7A l.)4 4.3»,
TEOEPEILIOAE . 7.70 .71 5.8?
SAFrLLinAF J.R3 1.77 .81
CarsTACFA no 1i.77 ^3
Hni:AC«-4F .73 ,14 i.t,
rpA>ir,iriin4E .73 .n, 3.23
^r'n10*' A '?3 •'* z*:ji
nE«»A9ESTUCF.tF .37 . 4 ,.7;,
M»T»"TI« .37 .07 ,.03
POFY TAI4 WITH FOEQ. nCCllB. L1"1;1; TMAN 5 ANO NUMfo
raupocJjJriM BgTn_)_F5;<; JMJN, 1 ABF Fji^L'JUEJ) FPOM TM
SHAk4»jON*WF |r>l
EVENNESS INO
AL<~ULATM» ot" nivFasltv INDITES)
JARCF 1NDFJ .Ifj m 13
to OlvEBSITY 3.M 3.«j
t* .6? .66
«
U II 41
« 4 O
e v -o a
1:15. ss
SSSHSSll
* 3 >, ffl v. E "i
JC
I l t_{ J^J |U ~"W
|
a .3. • i
5 S S J!S6333SS
100 120 140 160
OF OCCURRENCE
PBFY PERCENT
I.P.I. TOTAL IRI
1272.9 43.11
749. s 25.38
631.9 21.4(1
37. * 1.27
25.0 .85
22.9 .7R
23.' .79
76.7 .«9
27.7 .77
4.5 .15
14.1 .49
8.4 .28
36.0 1.2?
1.? .04
2.5 .08
I.A .04
.5 .07
.7 .02
.4 .01
1CAL ANO G°>VI*
-------
Table B-17. Prey composition (frequency of occurrence) of high cockscomb
at San Simeon, California, documented by Barton(1974).
-------
Table B-18. Prey composition (frequency of occurrence) of high cockscomb
at Second Narrows, Burrard Inlet, B.C., documented by Pepper
(1965).
r-*u?\?n'tn?. - S
(HIGH COCKSCOMH
OF o^LATIVF IMDOPTAMCF. (I.P.I.) TABLE
FILE I OF NT. &EF «>0. STATION SLSTA
MIM.
G"AV.
COMP.
I.P.I.
PfPCENT
TOTAL IRl
A|
17.^0
1S.*0
'.•F.PEIDAF
?. 10
PDFY TArA WITH FOF.O. OCCUR. LE^^ TH4N S ANQ NUMERICAL AND GPAVIMETPlC
BOTH LESS TH«N 1 4CF EXCLHOFO FOOM THE TARLF AND PLOT
" CALCULATION OF DIVERSITY INDICES)
MOT
SM4MMON-WF
DIVERSITY
.00
.on
.00
.00
.00
.00
.00
.00
.00
187
-------
INDEX OF RELflTIVE IMPORTRNCE (I.R.I.) OlflORWt
FROM FILE IOENT. 76-78. STRHON HLSTH
8842121401 XIPMISTER RTROPURPUREUS
BLRCK PRICKLEBHCK
PCT. COMPOSITION BY WEIGHT PCT. COMPOSITION BY RBUNOflNCE
ococn.ik.ro N) *• en CD o
ooooooooooo
V
a •)
Rhodophy
Polychae
) 20 40 60 80 100
CUMULflTIVE FREQUENCY OF
FRE-)
PRF.Y ITEM OCCitP
r>AUMAR|DEA 67.XD
«APELL»PinAF 19.70
RHrOOPHYTA 14.39
POLYCHAETA 11.16
HAPOACTICOIOA «.11
IJNIOFMTIFIED fl.33
PAr.T-IACEAE 7.59
CHLOP1PHYTA 5.10
l.'LOTRICHiLES 3.79
nF_CM/\H£5T. 1 AT£AF JL.JL9
NE«FRTF.4 3.79
•5FLLOTA, ?.?7
SAPELLIOAF 1.5?
MOLLUSCS 1.5?
NATAMTIA 1.5?
AWr-MR4 " K5?
CH|.nPOPHYCEAE-7Yr,MFMATAUFS .76
STICHAFIOAE
PHOLIOIOAE
.76
.76
MJ-.
COMP.
47.01
16.3?
6.74
-SjJL-
1.94
4.6R
_a.i7^
3. ao
.57
_1J4
1.01
1.01
1.01
.57
1.14
.46
.?3
.34
.73
!s7
.11
.11
.11
• n v
q fl 4t -O ig IQ
T4 T3 « -H ^ tO -0
•S'u-Sco-j.cSc.S
UM^_-:Z=.
. ) __- ' ^^* 1
LJ^^
01
v n
m v ti
•a T» M u
O « W U -0 ^4
1 Il^slll
120 140 160 180
OCCURRENCE
GPAV. PREY PERCENT
COMP. I.R.I. TOTAL 1RI
9.04 1709. p 73.39
.66 134.6 7.65
10.60
10. ao
.SLl
5.10
17.31
_a.o7
3.10
1.10
7.0«
.70
.05
.00
1.83
.04
1.31
a. 93
2.41
4.67
1.69
1.03
l.SH
5.74
a. 06
a49.5 5.70
145.0 3.33
34.4 .79
58.7 1.34
166. «. J.8I
33.4 .76
6.1 .15
6.5 .15
a. 5 .06
7.1 .05
5.5 .17
l.n .04
7.7 .06
4.0. .11
4.7 .10
7.4 .17
7.9 .07
1.7 .03
1.5 .03
4.4 .10
1.6 .04
PREV T»xA WITH FDEO. OCCl'P. LF-5S THAN 5 AND MJMEPICAL. Ann GRAVIMETRIC
COMPOSITION POTH LESS THAN 1 ARE EXCLUDED FROM THE T»8LE ANO PLOT
(O.I1T NOT FROM CA1 CAII ATIO'! OF DIVERSITY INDITES)
PERCENT On**TK|ANCF INPE1*
.77
.OH
4.74
.55
1.67
Fig. B-63. IRI prey spectrum of black prickleback in littoral habitats
along the Strait of Juan de Fuca.
188
-------
Table B-19. Prey composition (frequency of occurrence) of black prickleback
at San Simeon, California, documented by Barton(1973).
"(BLACK PPICKLER4CK )
I'lflF' OF DEL4TIVF I'.'POPTfMCF (I.R.I.) TARLF
FRIIM FIlE IH^NT. 9FF SS. 9TATIOM SLSTA
PPFY ITFw
FPFO
OCC'IP
MIJM.
CO^P.
GP.AV.
COMP.
I.P.I.
PFPCENT
TOTAL IRI
HLVA SP.
R I r- 1 P T T »! A
_SMITHORA SP.
P. 00
<, . o n
PETROLISTHES SP.
CPFY TivA WITH FPFO. OTi|3. LFSS THAN S AND NUMERICAL AMD GRAVIMETRIC
<-T>PnciITl'Vi ROTH LE<^<^ T~,AN 1 A = F FxCLUDEO FoQM THE TARLF. ANP PLOT
(HUT NOT F30M CAlCijLATlON Of OIvtPSlTY INDITES)
T OOWI'I\NCF I'lOfx
<;HAMNI)N-WFIMFP CIVEPMTY
"
.00 .00
.00 _ .00
.00 " .00
.00
.00
.00
189
-------
Rock Prickleback
Although not as prevalent in intertidal collections as the black
prickleback, the rock prickleback occurred at most of the intertidal sites
along the Strait of Juan de Fuca and were common at Slip Point and Twin
Rivers. Numerically, the IRI prey spectrum of rock pricklebacks (Fig. B-64)
was more diverse than that of black pricklebacks. Gammarid amphipods were
the predominant prey organism but composed less than half of the total IRI.
Instead, algae made a greater contribution; Rhodophyta, Chlorophyta,
Phaephyta, Ultrichales, Bangiales, and Gigartinacea combining for 44.8% of
the total IRI.
Algae, principally Smithora sp., Ulva sp. and Plocamium sp., were also
the pricnipal diet constituents, based on frequency of occurrence, of rock
prickleback collected at San Simeon, California (Barton 1974); gammarid
amphipods were the only prey animals (Table B-20).
Ribbon Prickleback
A ribbon prickleback from beach seine collection in northern Puget Sound
had 14 gammarid amphipods in its stomach.
Penpoint Gunnel
Penpoint gunnel from gravel pocket beaches in northern Puget Sound had
consumed oniscoidean isopods and gammarid amphipods (43.8% and 43.4% of the
total IRI, respectively), valviferan isopods (9.3%). shrimp (1.2%), and
several other epibenthic crustacean taxa.
Penpoint gunnels also appeared frequently in both beach seine and tidepool
collections along the Strait of Juan de Fuca and were most numerous at Twin
Rivers and Beckett Point. Epibenthic crustaceans—gammarid amphipods,
harpacticoid copepods, mysids, and valviferan isopods (Idotea sp.)—were the
most important prey in the spectrum (Fig. B-65), composing 88% of the total
IRI. Benthic polychaete and nemertean worms composed 7.4%.
Crescent Gunnel
As with the penpoint gunnel, crescent gunnel in northern Puget Sound
preyed upon epibenthic and benthic organisms. Gammarid amphipods were the
principal prey item, totaling 78.4 percent of total IRI. Harpacticoid copepods
were less important, accounting for 10.2 percent. Tanaids made up 4.7
percent; polychaetes, 2.5 percent; valviferan isopods, 1.1 percent; and a
variety of epibenthic crustaceans contributed less than 1.0 percent of the
total IRI. The diet composition of crescent gunnels from the eastern
shoreline was quite similar to those in FRl's San Juan Island collections.
Gammarid amphipods predominated (85.4 percent of total IRI), while polychaetes
(8.8 percent), crab larvae (2.7 percent), and hyperiid and caprellid amphipods
(each at 1.1 percent) were the less important prey.
190
-------
100
INDEX OF RELRTIVE IflPORTflNCE (I.R.I.] DIRGRflM
FROM FILE IDENT. 76-78. STHTION RLSTR
8842121402 XIPHISTER flUCOSUS
ROCK PRICKLEBRCK
RDJUSTED SflMPLE SIZE 87
60
£
§
£ 40
8
§ 20
(_)
§ 20
UJ
3
&
40
O
1 60
^ 80
o
Q-
POFY TTFf
CP^ATROMAT j n &r
CHpnriPHYC^ A P - -4. fl *• I T-
WIDENTIFIED"
TMcrrra
n
j:
(.
c
5
11
i r-h-i \
— -KTT
' — — T MJ
0}
01
,H
rt
00
c
, s: aixiai^Exci
•H ^ O O(XtO£OX'H4
M a. -^ m o jr a. ^ D. 4J
n o P . -H >-. a o at o t-
£ O O -HC^Hr-Hrt^O&O
(8 ,C ^H £3(5^0X10-^1^^
0 20 40 60 80 100 120
CUMULRTIVE FREQUENCY OF OCCURRENCE
FPFO Nil". GRAV. PPET PERCENT*
ncC'io COUP. COMP. I.P.I. TOTAL IRI
36.7% ?fl.?l 3.09 1151.3 43.01
IP. 10 10.^3 9.7B _ 379.) 14.16
]7.?<, S.06 4.19 ?11.? 7.B9
]3.«-4 5.5i, 4.e>0 ]?8.? 4.79
._ 10.34 11. 5.1. _ 1?.60 __,?50.2 9.35__
9.?0 If.O" 7.«3 164.6 6.15
fl."5 2.0? 15.2? 13S.7 5.1«
f-.9Q 3.53_ 7.69 _ 77.3.-.. 2.B9_
6.9(1 ?.02 .5? 17. c .65
£LE<; "=.75 ^.04 3.B5 51.1 1-91
'.30 1.01 .00 2.3 .09
1.15 .25 4.54 5.5 .21
1.15 .25 1.01 1.4 .05
1.15 1.01 1.56 2. .09
l.lc .25 9.56 " 11.3" .42
13
ra o
^ *J D.
U O
-, IK •**
£6
\l
«
RU
\
o» \
10 01
01 10
U 01
3 <0 U
H C (0
3 O ^
H oi j:
-i oo a.
J O O
H E rH
S. « tH
- 4J X
S££
40 160
_ PPFY TAx« .ITH FDEQ. OCCUR. LF-;"; THAN 5 AND NI)«EPICAL AND OPAvI»ETR!C
COwPn-ITlON HTTH LE^"; THJ-J J APF >•_ xCL'lOt'D F'of)" THE TABLE ANn PLOT
(BUT Nl^T FCA.. rt| ClJ'_AT I^V OF 0
nnM!»jn;iCE" INOfx
-WF T^lK c? DIVERSITY
.13
3.55
.73
.09
3.74
.77
2.79
Fig. B-64. IRI prey spectrum of rock prickleback in littoral habitats along
Strait of Juan de Fuca.
191
-------
Table B-20, Prey composition (frequency of occurrence) of rock prickleback
at San Simeon, California, documented by Barton(197A).
PPFOATOP
'iijcosus
(ROCK PRICKLF8AC"
OF RELATIVE IMPORTANCE d.p.i.) TABLE
FPOM FIlE IOENT. OFF S5. STATIOM 5LSTA
PQFY I
FREQ
NUM.
COMP.
GPAV.
COMP.
PPEY
I.P.I.
PERCENT
TOTAL IRI
SMITHORA SP.
PLOCAMIUM SP.
l?.no
4.00
4.00
4 . il 1
4.00
RHODOGLOSSUM SP.
_CLADOPHORA SP.
PHVLLOSP60IX S
DPFY TAxA ^ITH FPFO. OCCllrt. LF^S THAN S ANO NUMERICAL AMO
COMPOSITION BOTH I ESS THAN I ARF EXCLUDED FPOM THF TARLE ANO PLOT
(RUT NOT F30« CA| CUL*TION OF DIVERSITY INDICES)
PERCENT OnMInAMCP INDEX
SH4NMOM-WFIMFp DTVFPSITY
INOF*
.on
.no
.no
.on
.00
.00
.00
.00
.00
192
-------
CO
•z.
o
8
Q_
INDEX OF RELRTIVE IMPORTRNCE (I.R.I.) OIBGRRH
FROM FILE IDENT. 76-78. STflTION RLSTfi
8842130101 RPOOICHTHYS FLRVIDUS
PENPOINT GUNNEL
100 ROJUSTED SHMPLE SIZE 88
80
60
40
Q.
g
(_)
20
20
40
60
80
100
:rflk-i-uj
I
eooait.
20
40
60
80
100
120
140
160
CUMULRTIVE FREQUENCY OF OCCURRENCE
FPEO NU»'. GCAV. PPEY PERCENT
OCCUP COUP. COMP. I.R.I. TOTAL IPI
H4CPACT1C01DA.. .__
MYCIOACEA
Wf.l. V If EPA
comrpouAT IHAF
K 4TAMT I A
POLYCHAETA
CPfY TAX' WITH foEO. OCCllrf.
rn"on<; ! T Io>, ROTH Lf.5 THAN 1
(&'JT '.TIT CBOM CALCULATION o>"
PfPCFNT nOMlMflhjCF INOEX
SM AfyMO'J-WF I MTP h I V^RS 1 T~Y~
51.14 ?S.96 13.22 'n03.7
13.64^28.75-. .23— -395.7
I'.SO 10.96 19.54 381.3
1?.SO 14.33 21.3« 446.4
1?.50 2.02_ie.92 761.7
ti.OQ ?.8» .9"? 35.1
7.95 ?.?) .73 ?3.4
7.95 -.2.02- 3.55_ 44.3
6.S2 S.19 4.75 67.1
4.55 .87 ?.71 16.?
.._ 4.55 .87 3.78 ?1.1
4.55 .67 ?.31 13.^
3.41 .87 3.44 14.7
?.?7 .19 3.96_ 9.4
LF<;<; THAN 5 AMP NUMERICAL AMO
ARF FxCLIIOEO FDpM THE TARLE
DIVERSITY INOICFS)
.19 .15
?.9? 3.14"
.64 .68
53.60
10.57
10*20
11-94
7.00
.94
.63
1.13
1.81
.43
.56
• 36
.39
.25.
GPAvIMETPIC
ANn DLOT
.33
?.26~
.49
Fig. B-65. IRI prey spectrum of penpoint gunnel in Strait of Juan de Fuca.
193
-------
In the Strait of Juan de Fuca, crescent gunnels were common in inter-
tidal collections at Twin Rivers, Morse Creek, and North Beach and beach
seine collections at Twin Rivers which all contained crescent gunnel. Except
for dipteran insects, all the major prey organisms were epibenthic crustaceans.
Gammarid amphipods composed over 80% of the IRIj isopods (including sphaeromatid,
idoteid, and valviferan species), 7.4%, munnid crabs, 3.4%- and harpacticoid
copepods, 2.7% (Fig. B-66).
Saddleback Gunnel
Saddleback gunnels occurred in the same habitats in northern Puget Sound
and had much of the same prey composition as the more common crescent gunnel.
Amphipods were also the principal prey (49.7 percent of the total IRI) but
oniscoidean isopods (not found in 7_. laeta stomachs) ranked a close second
(32.9 percent) in importance. Polychaete annelids (7.4 percent), harpacticoid
copepods (5.6 percent), cumaceans (2.0 percent), and valviferan isopods (2.0
percent) were also in these stomachs.
In the Strait of Juan de Fuca, gammarid amphipods were important to the
diet (75% of the total IRI); secondary prey were sabellid worms, mysids, and
juvenile hippolytid shrimp (Fig. B-67).
Pacific Sand Lance
Over both northern Puget Sound and the Strait of Juan de Fuca, Pacific
sand lance were similar in occurrence and distribution to juvenile Pacific
herring. In the former region, beach seine catches of Pacific sand lance
were most frequent and numerous at Eagle Cove, and townet catches, at Point
George and Westcott Bay. Along the Strait, both beach seine and townet
collections at Dungeness Spit and Kydaka Beach yielded high numbers.
Pacific sand lance were basically pelagic feeders with an even more
specialized prey spectrum than juvenile Pacific herring. In northern Puget
Sound calanoid copepods composed 88.5 percent of total IRI and gammarid
amphipods 9.0 percent. The prey spectrum from the Strait of Juan de Fuca
was even more oriented toward calanoid copepods (Fig. B-68).
Over 75% of the prey biomass of Pacific sand lance collected in nearshore
habitats at Kodiak Island, Alaska, consisted of calanoid copepods, supplemented
by crustacean zoea and nauplii and larvaceans (Harris and Hartt 1977).
Calanoid copepods are, in fact, the almost universal prey organism of all
other sand lance species (Ammodytes americanus, A_. dubius, A_. marinus. A_.
tobianus and A^ personatus) occurring in north temperate waters of the Atlantic
and Pacific Oceans (Meyer et al. 1979; Reay 1970; Scott 1973; Sekiguchi 1977;
Senta 1965).
Speckled Sanddab
Speckled sanddabs from the Strait of Juan de Fuca (Beckett Point) con-
tained principally polychaetes and gammarid amphipods. Other less commonly
utilized prey included bivalves and their siphons, calanoid copepods, shrimp,
194
-------
INDEX OF RELRTIVE IMPORTHNCE (I.R.I.I Q1RGRRH
FROM FILE IOENT. 76-78. STRT10N RLSTR
8842130205 PHOLIS LRETR
CRESCENT GUNNEL
HOJUSTEO SHMPLE SIZE = 97
100
20
40 60 80 100 120 140 160
CUMULRTIVE FREQUENCY OF OCCURRENCE
180
PREY ITEM
~FREONUM. GR»V. PPEY PERCENT
OCCUR COMP. COUP. I.R.I. TOTAL IRI
SPHAFRO'<^ _•; AND NUMERICAL Axn Go Ay T"E TB 1 C
COMPOSITION POTM Lf.sc THAN 1 ABF f«CLnl)Eri FRO" THE TAULF "iNO^OLOT
.
(BUT HOT FPOM CALCULATION OF DIvFH«;ITY INDICES)
PERCENT DOMINANCE INOEI
SHA»,NON-'
-------
INDEX OF RELflTIVE IMPORTANCE (I.R.I.) DlflORflM
FROM FILE IDENT. 76-78. STRTION flLSTfl
8842130206, PHOLIS ORNfiTfl
SflODLEBflCK GUNNEL
a
lOOr
80
60
8
a.
§
u
00
z
o
40
20
20
+0
60
80
100
(U
LI _ ) dj
X\ TJ
t-> O
IS
t-> O t) -H O >, O
o) D.
-------
s
o
in
o
a.
£
100
80
60
40
20
20
•40
SO
80
INDEX OF RELRTIVE IHPORTRNCE (I.R.I.) OIRORHH
FROM FILE IDENT. 76-78. STflTlON flLSTR
8845010101 - RMtlODYTES HEXRPTERUS
PRCIFIC SRNO URNCE
flDJUSTED SRhPLE SIZE = 43
100
10 15 20 25
30
35
40
45
PPEY ITEM
CUMULfiTIVE FREQUENCY OF OCCURRENCE
F4EO NUM. GRAV. PBEY PERCENT
OCCUR COMP. COMP. I.P.I. TOTAL IRI
CALANOIDA
30.53 90.21
2.33 .02
T7.06
97.3?
145.9 ?.63.
P°FY TAXA WITH FBFO. OCCUR. LE";1; THAN ^ ANO NUMERICAL AND GOAVIMETP.IC
_CBMPQ£lllfl?j JOIH LE«,S JLMAN 1 . ARE. EXCLUOEO FROM. THE. TABLE. AND_PLO.T_
(PUT NOT FSOM CALCULATION OF OIVEPSITY INDICES)
PFOCFNT. OOMlKi
SHf^^lN^N-wF INF
DIVERSITY .09 .99 .18
.03 .3S .Oft
Fig. B-68.
IRI prey spectrum of Pacific sand lance in Strait of Juan de Fuca.
197
-------
amomuran crabs, one isopod, and algae.
Pacific Sanddab
Winter beach seine collections at Dungeness Spit and Beckett Point
produced Pacific sanddabs. Gammarid amphipods were common prey to three,
contributing 68.4 percent of the prey and 3.8 percent of the prey biomass.
Mysids (Neomysis sp.), shrimp (61.2 percent total biomass), and polychaetes
were the other prey items.
Rock Sole
Adult rock sole were caught, though not in abundance, in the cobble
and sand/eelgrass habitats of southwestern San Juan Island. The prey
spectrum from northern Puget Sound was extremely broad. Prey items, in
descending order of importance, were flabelliferan isopods, gammarid amphipods,
bivalve siphons, polychaetes, cumaceans, bivalves, brachyuran crabs, and fish.
Rock sole from collections at two Guemes Island sites and Cherry Point along
the eastern shoreline had consumed principally gammarid amphipods (88.9 percent
of total IRI); crabs (4.4 percent), bivalves (3.0 percent), and polychaetes
(2.4 percent) were only supplemental organisms.
Rock sole in the Strait of Juan de Fuca were benthic feeders, preying
principally on polychaete annelids (75% of the total IRI) (Fig. B-69). Epi-
benthic gammarid amphipods (12.6%) and tanaids supplemented the diet.
On the basis of biomass, fish (Pacific sand lance) were more prominent
in the diet of rock sole collected in the nearshore environs of Kodiak Island,
Alaska, although gammarid amphipods, polychaete annelids and bivalves were
important numerically (Harris and Hartt 1977).
English Sole (Juveniles)
Juvenile English sole were the most frequently caught species of the
nearshore demersal assemblages in northern Puget Sound, and were most
prevalent at Westcott Bay (mud/eelgrass) and Eagle Cove (sand/eelgrass).
Overall, cumaceans dominated the prey spectrum with 74.8 percent of the total
IRI (Fig. B-70). Gammarid amphipods (11.7 percent), polychaete annelids
(8.8 percent), tanaids (1.1 percent), crabs (1.0 percent), and bivalves (0.3
percent) were of secondary importance. Juvenile English sole were also common
in sand/eelgrass and mud/eelgrass habitats along the eastern shoreline. All
the prey taxa were similar; diet composition in this region was dominated
by gammarid amphipods (87.7 percent of total IRI), with cumaceans (8.4 percent),
polychaetes (2.0 percent), and bivalves (1.4 percent) providing lower inputs
(Fig. B-71).
Juvenile English sole were the most widely and evenly distributed species
at the eight beach seine sites sampled by the MESA program in the Strait of
Juan de Fuca. The overall prey spectrum (Fig- B-72) was equally divided among
benthic glycerid and gonaid polychaetes, bivalves (including Clinocardium
nuttalli), epibenthic gammarid amphipods, cumaceans, harpacticoids, tanaids,
and mysids (including Archaeomysis grebnitzki).
198
-------
INDEX OF RELflTIVE IMPORTRNCE (I.R.I.) OIHDRRn
FROM FILE IDENT. 76-78. STRTION RLSTH
8857040801 - LEPIOOPSETTH BIL1NEHTR
ROCK SOLE
fiOJUSTEQ SRMPLE SIZE 66
COMPOS
BY HEIGH
100
150
200
250
300
3SO
CUMULHTIVE FREQUENCY OF OCCURRENCE
PPEY ITEM
POLYCMAETA
TANAIOACFA
C.AuvARIO'E
PIVALVIA
UNIDENTIFIED
EUCAPIDA-DECAPOUA
CAPPFLLIPAE
GASTDOPOOA
NE"ATOOA
NATAHT1 A
CADOI IDAF '
ATFI FCYCL IOAF
CANCPJDAF
PIIIC'II.ANIC'E
PHPL 10IOAF.
iMunDYTIDAE
ANTHIIPIDAE
FHEO
OCCUB
84. «5
54.55
54.55
50.00
Pfl.79
15.15
9.09
9jfl9
6.06
4.55
4.55
.5?
.52
:i .52
.5?
.52
.52
Nil". GBAV.
COMP. COMP.
56.91 29.36
6.6A .20
17.94 2.06
5.11 7.37
4.41 .41
i.eo 1.01
.46 .94
.21 .01
l.?S .00
.73 2.15
.23 17.49
.12 1.77
.06 8.31
.12 1.67
.06 11.51
.12 7.13
.17 1.4?
.12 1.30
PBEY
I.B.I.
7119.5
375.0
1091.2
624.1
138. B
42.6
12.7
7.1
1.5
5.1
10. »
80.6
2.9
13. t
2.7
17.5
3.1
11.1
2.4
7.1
PERCENT
rOTAL IRI
74.84
3.83
6.39
1>42
.44
.13
.on
.02
.06
.11
.8?
.03
.11
.03
.18
.03
.11
.02
.02
POFY TA»A »1TM FOFB._QCCL|P. LESS THAN S A^ll JUUMEPlCJLL__A»(D_0a^v 1 METRIC
COMPOSITION BOTH LESS T1«N 1 APF FXCLIIOED FPO» TM£ TABLE AND PLOT
(«I|T MOT FROM CALCULATION OF DIVERSITY INDICES)
PFOCENT OOHlMtNCF IMOF«
SHANNON-UFINFP DIVERSITY
FuFNNFSS INDE«
.37
2.21
.15
3.36
.51
1.39
Fig. B-69. IRI prey spectrum of rock sole in shallow sublittoral
habitats along Strait of Juan de Fuca.
199
-------
INDEX OF RELflTIVE IttPORTHNCE (I.R.I.) OIRGRflfl
FROM FILE IDENT. N PGSO. STflTION flLSTfl
PREDflTOR 8857041301 PRROPHRYS VETULUS
(ENGLISH SOLE ) PDJUSTED SflHPLE SIZE - 46
100
80
60
40
20
H 20
40
s
u
60
80
100
50
100
150
200
250
300
CUMULflTIVE FREQUENCY OF OCCURRENCE
PPEY
ITFM
rpfrj
OCCliP
NUM.
COUP.
G»AV.
COMP.
PPEY
I.O.I.
PtPClNT
TOTAL IP!
r- 4u
POI YCHAF.TA
TAKA1DACEA
HAOP4CTICOIOA
OXYRHYNCHA
f.7.00
63.00
•i^.OO
35.00
I3;00
13.00
11.00
9.00
?;no
- 49. BO
?7.ei
8.74
?.40
I^I^i —
.41
4; 17 —
1 .44
.9?
33.07
7.98
7.0?
.15
— .66
.00
.04
?.61
37.05
~?37«~
5.3
46.3
36.5
75.9
6?.00
?S.?0
9.70
1.00
.30
.10
~ .50
.40
— .10
-pOFY~TAr« -WlTH-TDfO; OCCIIRT Lfet^" THAfJ"? AND" NUMEPICAC ~*ND 'GP*V IMETR 1C
COMPOSITION BOTH LESS THAN 1 APE EXCLUDED EOO" THE TABLE AND PLOT
(RUT NOT rpf)M CA( CULATION OT HIVEPSITY INDICES)
PERCENT
DIVERSITY
------ .34'- ,2f>
1.90 1.8?
---- .60- .61
1.44
.45"
Fig. B-70. IRI prey spectrum of juvenile English sole in shallow sublittoral
habitats of northern Puget Sound.
200
-------
INDEX OF RELflTIVE IHPORTfiNCE (I.R.I.) OIRGRRM
FROM FILE IOENT. UH BS. STRTION flLL
PREOflTOR 8857041301 - PRROPHRYS VETULUS
(ENGLISH SOLE ) MJUSTEO SflHPLE SIZE = 120
100
8
| 80
I -
§
E 40
| 20
20
£
£
§ 40
»-•
I—
60
100
=a-
•o 1-1 ex M o
50 100 150 200
CUMULATIVE FREQUENCY OF OCCURRENCE
250
PREY ITEM
FPEO NUM. GPAV. PPEY
_OCCUR_ .COHP. CQMP. __ l.R..J_.
PEPCENT
IPJAL .IP_I_
GAMMARIDEA
ClJMACEA
POLYCHAETA
RIVALVIA
ISOPODA
PLEOCYEMATA-CARIOFA
Jf_ANAIDACEA
CNIOARIA
CIRPIPEDIA
AMPHARETIOAE
NE-ATOOA
92.00
42.00
2S.OO
17.00
p. no
».no
a. oo
A. 00
ft. 00
A. 00
fl.OO
73.06
17.96
1.63
1.2?
2.45
.41
.41
.41
.41
1.63
.41
60.33
9.92
6.26
9.92
T.31
1.65
.00
1.65
1.65
3.31
.00
12271.9
1171.0
247.2
189. 4
46.1
16. S
3.3
2.1
2.1
39.5
3.3
87.70
8.40
1.80
1.40
.30
.10
.00
.00
.00
.30
.00
PREY_TA«A WITH FPEO. OCCll». LESS_THAN_5_ANn NUMERICAL, AMn_GPAVIMETRlC_
COMPOSITION BOTH LESS THAN 1 ARE EXCLUDED FROM THE TABLE AND PLOT
(BUT NOT FROM CALCULATION OF DIVERSITY INDICES)
PEPCFNT DOMINANCE INDEX
SHANNON-WFINEP DIVERSITY
EVENNESS INDEX
.57
"73<»
1.3* 2.0?
.39 .64
.78
.72
.26
Fig. B 71. IRI prey spectrum of juvenile English sole in shallow sublittoral
habitats along eastern shoreline of northern Puget Sound.
201
-------
INDEX OF RELflTIVE IMPORTRNCE (I.R.I.) DIflGRflM
FROM FILE IDENT. 76-78. STflTION flLSTfl
8857041301 - PflROPHRYS VETULUS
ENGLISH SOLE
100
LJ
o
i so
1
• «
03
§
£ 40
8
~
8 20
*-:
LJ
fl
U
(_
r
2 20
UJ
3
CD
2 4°
»—
| BO
8
.-1 80
u
a.
inn
iooc
nuuuon_u onnri_i_ oitc. = ooo
o>
0) (0
0) (0 ^
CO ••-< 4-« O
flj C >N >,
4-1 O <-H U
1-. OC O 0)
E > (Q E E ci-tn--i^-i*-t
ft. u cj: OPQHSZXXZ
i i i i
) 50 100 150 200 2E
ITFM
CUflULflTIVE FREQUENCY OF OCCURRENCE
FPFO NUM. GPAV. DPEY PEPCENT
OCCUR COMP. COMP. I.P.I. TOTAL IPI
Pfl YfHAFTA
CI.PMACEA
r-AUMJPlflf A
GAVMAPTQ4E;
PI»A| v! ^
TAVAIDACEA
HAPPACTICOIOA
MY«in*<"EA
Hni.OTHiioniDFA
HOLfiTHiiPnlOFA AsPinnCHionTACf A
h'AT'tMTIA
NFUFPTEA
TQANGOfJIDAE
HIPUOLYTJDAE
ATFLFCYCLIDAE
44 S4
4ft. 71
39.89
1°.95
]O.40_.
19.40
1ft. 94
in. 38
3.^1
3.83
3 . ?8
?.4ft
1 .09
.27 _
.'7
13.08
PO.S3
17.08
ft. 46
2.45.
6.10
?ft.79
1 . *9_
.59
.47
1.09
.13
.03
.02
.0?
28.68
13.51
17.03
9.44
_3.60
2.05
1.00
6.4ft
3.31
3.37
.39
1.57
1.39
1.44
1.07
IflftO.n
1385.7
1 360. ft
317.1
117.4
158.?
470.8
87.7
14.9
14.7
4.1
4.?
1.5
.4
.3
32.02
23.86
?3.4?
5.4ft
_2>02
2.7?
8.10
-- 1.51. . .._
.26
.25
.08
.07
.03
.01
.01
J?°.EY_ TA^A WITH F.PEO. OCCUR. LE5S_JHA_N .5 AND_ NUMERICAL .AN
roMpntjiTioM '•OTH LE^S THAN i ARE EXCLUDED FROM THE TABLE AND PLOT
(R|lT MOT FPD" C«l CUI.ATIOtJ OF DIVERSITY INDITFS)
PERCENT OOHlNAr4CE INDE*
DIVERSITY
.17 .15
2.99 3.4?
.54 __ .61.
.23
2.47
..44
Fig. B-72. IRI prey spectrum of juvenile English sole in shallow sublittoral
habitats along Strait of Juan de Fuca.
202
-------
Starry Flounder
Adult starry flounder were frequently captured in beach seine collections
in northern Puget Sound (Eagle Cove and South Beach) from July through
November though never in large numbers. The most frequently consumed prey
organisms were flabelliferan isopods which accounted for 58.9 percent of
the total IRI. Fish (18.2 percent) were second in importance, followed by
gammarid amphipods (8.2 percent), epicaridan isopods (4.5 percent),
polychaetes (3.7 percent), gastropods (3.3 percent), and turbellarians (1.2
percent). The amphipods were primarily Atylus sp. but also Eusiroides sp.
and Amphithoe so. All prey, except perhaps the fish, were epibenthic or
benthic organisms.
Juvenile starry flounder also appeared in beach seine collections along
the eastern shoreline, principally in sand/eelgrass (Birch Bay, East Guemcs
Island) and mud/eelgrass (Padilla Bay, Drayton Harbor) habitats in August
through December. While isopods (primarily valviferan) were still important
(30.2 percent of total IRI) in these samples, gammarid amphipods (33.4 percent),
barnacles (16.7 percent), and oligochaetes (11.8 percent) were much more
prevalent in the diets of starry flounders on the eastern shore than at San
Juan Island (Fig. B-73).
Although not as numerous as English sole, starry flounder occurred
along the Strait of Juan de Fuca in all but the Dungeness Spit beach seine
collections; juveniles and adults occurred in approximately equal proportions.
The overall prey spectrum (Fig. B-74) was quite similar to that of the rock
sole (Fig. B-69): polychaete annelids, gammarid amphipods, and tanaids
supplied the greatest proportions of the total IRI.
C-0 Sole
C-0 sole were caught during beach seine collections at South Beach and
Deadman Bay in northern Puget Sound. Their principal prey items were
flabelliferan isopods (45.8 percent of total IRI), fish (21.4 percent),
polychaetes (14.3 percent), amphipods (9.2 percent), and turbellarians (4.4
percent). One C-0 sole from a beach seine collection at southern Guemes
Island in July 1974 had 12 bivalves (98.0 percent of total biomass) and 10
pieces of algae (Rhodophyta) in its stomach.
C-0 sole collected from the Strait of Juan de Fuca almost exclusively
originated from the protected, sand-eelgrass habitat at Beckett Point.
Polychaete annelids, with over 80% of the total IRI, were the most important
prey taxa and bivalves contributed almost 13% (Fig. B-75).
Sand Sole
In sand sole from the eastern shoreline of northern Puget Sound (Birch
Bay), gammarid amphipods were the most important prey taxa, with 82.1 percent
of the total IRI (Fig. B-76). Polychaetes supplied 8.3 percent and epibenthic
organisms—tanaids (3.8 percent), cumaceans (3.4 percent), and valviferan
isopods (1.3 percent)—accounted for the remaining proportion.
203
-------
INDEX OF RELRTIVE IhPORTRNCE (I.R.I.) OIRGRHM
FROM FILE IOENT. HH BS. STflTION HLL
PREDHTOR 8857041401 - PLHTICHTHYS STELLRTUS
(STfiRRY FLOUNDER ) ROJUSTED SRNPLE SIZE = 22
100
a
i so
I 60
i
r 40
I
5 20
§ 20
8
4°
60
80
100
j: •-* -o -H
U O O -H
O CUV
20
40
60
80
100
120
140
160
CUMULRTIVE FREQUENCY OF OCCURRENCE
PSEY ITEM
GAMHARIDEA
ISOPOOA
TANAIDACEA
POLYCHAETA
BIVALVIA
OLIGOCHAETA
CAIANOIDA
NEt'ATOOA
FLA8ELLIFERA
CIRPIPEOIA
VALVIFEPA
PLEOCYEMATA-CAPIDEA
OSTEICHTHYES
PENAEIOAE
FPEO
OCCUR
3?. no
??.no
1<>.00
K.OO
10.00
B.OO
s.no
•5.00
s.oo
5.00
5.00
s.oo
s.oo
5.00
NUM.
COMP.
23.92
?7.?H
<..98
1.31
.<)
21.59
.33
3.99
2.33
6.ft6
i.on
3.65
GRAV.
COMP.
2.07
.61
.31
.3P
1 .99
11.03
.00
.04
1.91
76.60
.00
1.39
.38
3.06
PREY
I.R.I.
B31.7
752. n
74.1
23.9
29. *
293. «S
1.6
20.1
21.2
416.2
1 .6
10.2
6.Q
33.5
PERCENT
TOTAL IRI
33. 01)
29.90
2.90
1.00
1.20
11.70
.00
.80
.80
16.50
.00
.40
.30
1.30
_PRFY TAXA_WITH FPEO. OCCU".. LESS THAN. 5_ANO NUMEP 1C AL .AND GPAVIMETPlC._
COMPOSITION BOTH LESS THAN 1 ARE EXCLUDED FoOM THE TABLE AND PLOT
(RUT NOT FROM CALCULATION OF OIvFPSITY INDICES)
"PERCENT DOMINANCE INDEX
SHANNON-WFINER DIVERSITY
EVENNESS INDEX
.19 .60
2.76 1.36
.73 .38
.24
2.3S
.66
Fig. B-73. IRI prey spectrum of starry flounder in shallow sublittoral
habitats along eastern shoreline of northern Puget Sound.
204
-------
100
INDEX OF RELRTIVE inPORTflNCE (I.R.I.I DIBGRBH
FROI1 FILE IOENT. 76-78. STBTION BLS'B
8957041401 - PLHTICHTMtS STELLBRIS
STBRRY FLOUNOER
BOJUSTEO SBHPLE SIZE = 117
1
~ 40
§
?
X
1
COMPOS I
5
20
?n
40
60
80
inn
•
:
ii
1 — 1-4 Ln-r
o
1 = J 1 !„!=
t
1
.1
3 s
i 3 1 1 f 1 1 !S| £ 2
£ 3 till; 33fl3Z
40 60
OMJLBT1VE FREQUENCIf OF OCCURRENCE
iKinri nr on»Tiyr IMPBRTANCF il.P.I.I T»8i F
USING FlLElOa 76-79. »LST« FOR PLOT
FRFO NUM. GRAV. PREY PERCENT
OCCUR CO«P. COMP. I.R.I. TOT»L 1RI
GlWKOlnFt J9
r.Iv'dR"olFl01E
• unOYTIOit
» jln«F
0 TT1CMTHY5
P ^LIOIOAt
SO 13.
*fl ?.
« I.
9« ?.
13 5.
S* I
M :
•5
45
.1
14
"V
49
SI
26
11
114
04
04
63.16 3344.
.70 761.
.16 374.
2.97 69.
.91 170.
.20 13.
1.13 82.
.01 IS.
.19 29.
14.54 65.
3.?9 9.
2.45 7.
1.54 1.
1.56 1.
1.16 1 .
1 . 35 1 .
6§.06
7.63
1.4?
1.64
.11
.59
1.32
.14
• 01
.01
• 02
.0?
P-P-£Y_IAX4_klIH_rj:.F_0. -OCCUR. LESS JM1X 5_»SJ) NU»E"1C»L_»N!1 C-»»VI«ET9IC
ClwpnsITlnN PIU.I LC^1; TH»N | »RF E»CUinED Fon» THE HBLF «NO PLOT
OUT NOT FPO" C»I.CIJL*TInM OF 01VERSIT* INOIrFS)
PEOCC'IT
_£VfN'lt!S
Fig. B-74. IRI prey spectrum of starry flounder in shallow
sublittoral habitats along Strait of Juan de Fuca.
205
-------
100
INDEX OF RELflTIVE IMPORTRNCE (I.R.I.) DlflGRflM
FROM FILE IDENT. 76-78. STflTION flLSTfl
8857041601 - PLEURONICHTHYS COENOSUS
C-0 SOLE
flOJUSTEO SflMPLE SIZE = 19
1
1
DO
Z
o
"
1
§
I—
0-
1
UJ
3
ID
§
1
1
c
CJ
1—
CJ
O-
80
60
40
20
20
40
60
80
inn
jC
O
ft*
,
1 i 1 [~L
U
m
QJ
i -H
E C -H MEl-WjrO
oa u H =3 ooar.
11 .
11 .
?1 .
15.
c;.
q.
^,.
5.
q .
s.
47
16
1 1
58
5*
n5
79
?6
76
76
?6
?6
76
68 ?7
7.44
4.8]
7.19
4.ftO
1.97
1 .97
.22
6.5ft
1.31
.22
.22
.??
ft4.88
_J>1.64
1.2ft
.01
1.73
3.30
.07
.00
.01
.01
.J_8
6.59
.12
1)913.1 82
JR49.? 12
755.8 1
69. ft
199. q 1
1 10.9
12.2
__.- 1.2_ ._.
14.6
6.9
?• 1
35.8
l.
.09
.74
.7ft
.48
.18
.76
.22
.01 _
.24
.05
.01
.25
.01
~W I fnT FDE 0 . nCCHRT LFSS THAN 5 AMP NUMERICAL ANO GRAVIMETRIC
COMPOSITION BOTH LES<= THAN 1 ARF E»CLUDED FRO« THE TARLE AND PLOT
("III NOT F_P(""l_CAl C.yt.*T_IOM_0,F_njJ/fR<;JJY_I^JpXCEL';> __________
"ERCENT nn"lNANCE INPFX
SHA'JNO'J-WEI^EP DIVERSITY.
EVENNESS INOF»
.48 .47
1.81 _ 1.53
.49 .41
.69
_.96_
.26
Fig. B-75. IRI prey spectrum of C-0 sole in shallow sublittoral habitats
along Strait of Juan de Fuca.
206
-------
I
to
z
o
8
fc
S
INDEX OF RELRTIVE INPORTHNCE (I.R.I.) OIRGRRM
FROM FILE IOENT. WW BS. STRTION flLL
PREDflTOR 8857041701 - PSETTICHTHYS MELRNOSTICTUS
(SRND SOLE ) ROJUSTED SRHPLE SIZE = 16
100
80
60
40
20
2 20
CD
S
I—
P 60
^ 80
K
100
« -H C O
u > o c.
U fH 00-H
to id C JZ
50
100
150
200
250
CUMULRTIVE FREQUENCY OF OCCURRENCE
PREY ITFM
FPEO
_C)CCUR
NUM.
COMP.
GRAV.
COMP.
PREY
I.R.I.
PERCENT
TOTAL IRI
GAMMARIDEA
POLYCHAETA
VALVJFERA
TASAIDACEA
CUMACEA
BIVALVIA
CRANGONIOAE
AMPHIPOD^A-HYPERI IDFA
94.00
56.00
31.00
25.00
19.00
13.00
6. no
6.00
62.90
3.77
5.51
1*.81
8.99
1.45
.?9
.?9
53.27 J09?0.0_
15.89 1111.0
•00 170.R
3.74 513.7
. 5*
_ 5.61
.00
103.9
35.4
1.7
8?.1Q_
" B.*0
1.30
3.90
"3.VO"
.HO
.30
.00
TAXA WITH FREO. OCCUR. LESS THAN 5 AND NUMERICAL AND GRAVIMETRIC
COMPOSITION BOTH LESS THAN 1 ARE EXCLUDED FPOM THE TABLE AND PLOT ~ "
(HUT NOT FRO- CALCULATION OF DIVERSITY INDICES)
PERCENT DOMINANCE INDEX "
SHANNON-WfINER DIVERSITY
EVENNESS INDEX
.44 .34
1.71 1.98
.57 .77
.68
1.04
.37
Fig. B-76. IRI prey spectrum of sand sole in shallow sublittoral habitats
along eastern shoreline of northern Puget Sound.
207
-------
In the Strait of Juan de Fuca.sand sole were almost as abundant as
English sole but originated primarily from the four western beach seine
sites. The overall prey spectrum (Fig. B-77) showed a radical difference
from northern Puget Sound and from the other flatfish by the predominance
of epibenthic mysids (primarily Neomysis awatschensis but also including
N_. rayi and Archaeomysis grebnitzki, accounting for 88.9% of the total IRI)
and the absence of polychaetes. Other epibenthic crustaceans, such as
gammarid amphipods, cumaceans, and shrimp (including Crangon stylirostris
and Pandalus danae), were the secondary prey. Fish (including juvenile
Pacific herring, Pacific sand lance, tidepool snailfish, Liparis florae,
and sand sole, Psettichthys melanostictus) accounted for 31.5% of the total
prey biomass but were not common or abundant enough to provide a high (1.5%)
proportion of the total IRI.
208
-------
INDEX OF RELflTIVE IflPORTflNCE (I.R.I.) DIRGRflM
FROM FILE IDENT. 76-78. STRTION RLSTfi
8857041701 - PSETTICHTHYS HELHNOSTICTUS
SRND SOLE
flOJUSTED SRMPLE SIZE = 308
PPF.Y ITFM
CyrjULflTIVE FREQUENCY^ OF OCCURRENCE
F&EO MUM. " GRAV. PREY PERCENT
OCCIIP CO«P. COMP. I.P.I. TOTAL IRI
r,AWMARIOEA
CM'MCEA
OSTFICHTHYS
MNIOFNTIF IED
k'ATANTI A
CLI'PEIDAE
. AMworiYTIPAE
PI_FllPO"'FCTlnAF
67. ?1
3?. 14
9.09
A. 17
3.
-------
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(Embiotoca_ lateralis). Copeia, 1975(4):609-615.
Bane, G. and M. Robinson. 1970. Studies on the shiner perch, Cymatogaster
aggregata Gibbons, in upper Newport Bay, California. Wasmann J. Biol.
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Barraclough, W. E. 1967a. Data record. Number, size and food of larval and
juvenile fish caught with an Isaacs-Kidd trawl in the surface waters of
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Report Series 926, 79 pp.
Barraclough, W. E. 1967b. Data record. Number, size composition
and food of larval and juvenile fish caught with a two-boat surface
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M.S. Report Series 928, 58 pp.
Barraclough, W. E. & J. D. Fulton. 1967. Data record. Number, size
composition and food of larval and juvenile fish caught with a two-boat
surface trawl in the Strait of Georgia, July 4-8, 1966. Fish Res. Bd.
Canada. M. S. Report Series 940, 82 pp.
Barraclough, W. E. 1967c. Data record. Number, size and food of larval and
juvenile fish caught with a two-boat surface trawl in the Strait of
Georgia, April 25-29, 1966. Fish Res. Bd. Canada, M. S. Report Series
922, 54 pp.
Barraclough, W. E. & J. D. Fulton. 1968. Data record. Food of larval and
juvenile fish caught with a surface trawl in Saanich Inlet during June
and July 1966. Fish Res. Bd. Canada, M. S. Report Series 1003, 78 pp.
Barraclough, W. E., D. G. Robinson & J. D. Fulton. 1968. Data record.
Number, size composition, weight, and food of larval and juvenile fish
caught with a two-boat surface trawl in Saanich Inlet, April 23-July 21,
1968. Fish Res. Bd. Canada, M. S. Report Series 1004, 305 pp.
Barton, M. G. 1974. Studies on the intertidal vertical distribution, food
habits, and movements of five species of eel (Pisces: Stichaeidae and
Pholidae) at San Simeon, California. M. A. Thesis, Calif. State Univ.,
Fullerton. 100 pp.
Conley, R. L. 1977. Distribution, relative abundance, and feeding habits
of marine and juvenile anadromous fishes of Everett Bay, Washington.
M. S. Thesis, Univ. of Washington, 57 p.
210
-------
Cross, J. N., K. L. Fresh, B. S. Miller, C, A, Simenstad, S. N. Steinfort
and J. C. Fegley. 1978. Nearshore fish and macroinvertebrate
assemblages along the Strait of Juan de Fuca including food habits of
the common nearshore fish: report of two years of sampling. Annual
Report to NOAA, MESA Puget Sound Office. Fish. Res. Inst., Coll. Fish.
Univ. Washington, Seattle, FRI-UW-7718. Also NOAA Tech. Memo. ERL MESA-32.
De Martini, E. E. 1969. A correlative study of the ecology and comparative
feeding mechanism morphology of the embiotocidae (surf fishes) as evidence
of the family's adaptive radiation into available ecological niches.
Wasmann J. Biol. 27(2):177-247.
Feller, R. J. and U. W. Kaczynski. 1975. Size-selective predation by juvenile
chum salmon (Oncorhynchus keta) on epibenthic prey in Puget Sound. J.
Fish. Res. Bd. Canada 32(8):1419-1429.
Feller, R. J. 1977. Life history and production of meiobenthic harpacticoid
copepods in Puget Sound. Ph.D. Thesis, Dept. Ocean. Univ. Washington,
Seattle. 249 pp.
Fresh, K. L., D. Rabin, C. A. Simenstad, E. 0. Salo, K. Garrison and L.
Matheson. 1978. Fish ecology studies in the Nisqually Reach area of
southern Puget Sound, Washington. Ann. Prog. Rept., March 1977 - June
1978, to Weyerhaeuser Co., Fish. Res. Inst., Coll. Fish., Seattle, FRI-UW-
7812. 151 pp.
Fresh, K. L. 1979. Distribution and abundance of fishes occurring in the
nearshore surface waters of northern Puget Sound, Washington. M.S. Thesis,
Coll. Fisheries, Univ. Washington, Seattle, 120 pp.
Gnose, C. E. 1967. The ecology of th striped seaperch, Embiotoca lateralis,
in Yaquina Bay, Oregon, M. S. Thesis, Oregon State University, 51 pp.
Harris, C. K. and A. C. Hartt. 1977- Assessment of pelagic and nearshore
fish in three bays on the east and south coasts of Kodiak Island, Alaska.
Final Rept. to OCSEAP/BLM (proposal RU 485, A-7, A-8, A-9 & A-ll). Fish.
Res. Inst., Univ. Washington. FRI-UW-7719. 190 p.
Healey, M. C. , R. J. LeBrasseur, J. R. Sibert, W. E. Barraclough and J. C.
Mason. 1976. Ecology of young salmon in Georgia Strait, pp. 201-207.
In G. R. Gundstrom (Ed.) Proc. 1976. N.E. Pacific pink and chum
salmon workshop, Alaska Dept. Fish & Game, Juneau.
Holmquist, C. 1973. Taxonomy, distribution and ecology of three species of three
species, Neomysis intermedia (Zerniavsky), N. awatchensis (Brandt) and
N. mercedis (Holmes) (crustacea, mysidacea). Zool. J. B. Syst. Bd. 100,
5:197-222.
Johnson, C. L. 1968. Food of the buffalo sculpin, Enophrys bison. J. Fish.
Res. Bd. Canada 25(4):807-812.
211
-------
Johnson, C.L. 1970. Notes on the intertidal life history of the northern
clingfish Gobiesox maeandricus (Girard). Amer. Midi. Nat. 83(2) -.625-627.
Jones, A.C. 1962. The biology of euryhaline fish (Leptocottus armatus
Girard). Univ. California Publ. Zool. 67(4):321-367.
Jones, B.C., and G.H. Geen. 1977- Food and feeding of spiny dogfish (Squalus
acanthias) in British Columbia waters. J. Fish. Res. Board Can. 34(11):
2067-2078.
Leaman, B.M. 1976. The ecology of fishes in British Columbia kelp beds;
Barkley Sound Nereocystis beds. Kept, to Map Resources Branch, British
Columbia Dept. Recreation and Conservation. Inst. Anim. Resource Ecology,
Univ. British Columbia, 80 pp.
Meyer, T.L., R.A. Cooper, and R.W. Langton. 1979. Relative abundance, behavior,
and food habits of the American sand lance, Ammodytes americanus, from
the Gulf of Maine. Fish. Bull. 77(1):243-253.
Miller, B.S., C.A. Simenstad, K.L. Fresh, F.C. Funk, W.A. Karp, S.T. Borton,
and L.L. Moulton. 1977. Puget Sound baseline program; nearshore fish
survey. Final Rept. to Wash. State Dept. Ecology, June 1974 - June 1977-
Fish. Res. Inst., Coll. Fish., Univ. Washington, Seattle. FRI-UW-7710,
220 pp.
Moulton, L.L. 1977. An ecological analysis of fishes inhabiting the rocky
nearshore regions of northern Puget Sound, Washington. Ph.D. Thesis,
Univ. Washington, Seattle, 181 pp.
Nakamura, R. 1971. Food of two cohabitating tide-pool Cottidae. J. Fish.
Res. Board Can. 28(6):928-932.
O'Connell, C.P. 1953. The life history of the cabezon Scorpaenichthys
marmoratus (Ayres). Calif. Dept. Fish and Game 93:1-76.
Quast, J.C. 1968. Observations on the food of kelp-bed fishes. In W.J.
North and C.L. Hubbs, eds., Utilization of kelp-bed resources in southern
California. Calif. Fish and Game, Fish. Bull. 139, 264 pp.
Reay, R.J. 1970. Synopsis of biological data on North Atlantic sand eels of
the genus Ammodytes, A. tobianus, A. dubius, A. americanus and A. marinus,
from the Gulf of Maine. Fish. Bull. 77(1):243-253.
Robinson, D.G., W.E. Barraclough, and J.D. Fulton. 1968a. Data record:
Number, size composition, weight and food of larval and juvenile fish
caught with a two-boat surface trawl in the Strait of Georgia, May 1-4,
1967. Fish. Res. Board Can., M.S. Rept. Ser. 964, 105 pp.
Robinson, D.G., W.E. Barraclough and J.D. Fulton. 1968b. Data record:
Number, size composition, weight and food of larval and juvenile fish
caught with a two-boat surface trawl in the Strait of Georgia, June 5-9,
1967. Fish. Res. Board Can., M.S. Rept. Ser. 972, 109 pp.
212
-------
Robinson, D. G. 1969. Data record. Number, size composition, weight
and food of larval and juvenile fish caught with a two-boat surface
trawl in the Strait of Georgia. June 4-6, 1967. Fish. Res, Bd. Canada,
M. S. Report Series 1012. 71 pp.
Scott, J. S. 1973. Food and inferred feeding behavior of northern sand lance
(Ammodytes dubius). J. Fish. Res. Bd. Canada 30:451-454.
Sekiguchi, H. 1977. Further observation on the feeding habits of planktivorous
fish sand-eel in Ise Bay. Bull. J. Soc. Sci. Fish. 43:417-422.
Senta, T. 1965. Nocturnal behavior of sand-eels, Ammodytes personatus
(Girard) Bull. J. Soc. Sci. Fish. 31:506-510.
Simenstad, C. A., B. S. Miller, J. N. Cross, K. L. Fresh, S. N. Steinfort and
J. C. Fegley. 1977. Nearshore fish and macroinvertebrate assemblages
along the Strait of Juan de Fuca including food habits of nearshore fish.
Fish. Res. Inst. Rept. to MESA Puget Sound Project. NOAA Tech. Memo.
ERL-MESA-20, 144 p.
Simenstad, C. A. and W. J. Kinney. 1978. Trophic relationships of out-
migrating chum salmon in Hood Canal, Washington, 1977- Final report
to Wash. Dept. of Fish, Fish. Res. Inst. Coll. Fish., Univ. Washington,
Seattle. FRI-UW-7810, 75 pp.
Tasto, R. N. 1975. Aspects of the biology of the Pacific staghorn sculpin,
Leptocottus armatus Girard, in Anaheim Bay. pp. 123-135. In: E. D. Lane
and C. W. Hill (Eds.). The marine resources of Anaheim Bay. Calif. Dept.
F\.sh. and Game. Fish. Bull. 165, 195 pp.
Wares, P. G. 1968. Biology of the pile perch (Rhacochilus vacca). M. S.
Thesis, Oregon State Univ., Corvallis. 93 pp.
Weller, D. B. 1975. The life-history of the shiner seaperch, Cymatogaster
aggregata Gibbons, in Anaheim Bay, California, pp. 107-115 In: E. D.
Lane and C. W. Hill (Eds.) Marine resources of Anaheim Bay, Calif. Dept.
Fish & Game. Fish. Bull. 165, 195 pp.
213
-------
APPENDIX C: SEA BIRDS AND SHORE BIRDS
Eighty-one species of marine or estuarine-associated birds are reported
or could be safely assumed to consistently occur in north Puget Sound and
the Strait of Juan de Fuca (Jewett, et al., 1953; Robbins, et al., 1966;
Alcorn 1971; Salo 1975; Manuwal 1977). Ten species occur in abundance and
represent sizable breeding or wintering populations; an additional 54 species
could be considered common, many of which are seasonal migrants and residents.
The remaining species are either not commonly encountered—e.g., they migrate
through the region offshore—or numerically unimportant (Table C-l).
The following species accounts discuss food habits and feeding behavior
of all species for which such data could be found. For many species,
especially the shore birds, there were few, or very unspecific, data avail-
able for this region. In those cases, information for that species occurring
outside the Pacific Northwest was utilized, or in the instances of no such
data, the diet was inferred from congeneric species. Several review
references, notably Jewett, et al. (1953), Eaton (1975), and Salo (1975),
were extremely useful in locating data on the general food habits of the
less-known birds.
The functional feeding groups of the 55 abundant and common marine and
shore birds associated with north Puget Sound and Strait of Juan de Fuca
habitats are summarized in Table C-2. Of these species, 19 (35%) utilize
fishes as their principal prey resources, as either obligate or facultative
piscivores; 18 (33%) feed mainly on benthic invertebrates in the littoral or
shallow sublittoral zones; 7 (13%) are omnivorous, eating both plants and
invertebrates; 5 (9%) are planktivorous; 4 (7%) are herbivorous; and 2 (3%)
are either parasitic, or like the bald eagle, facultative avivores preying on
both sea birds and fish.
Sixteen (29%) of the bird species feed in the shallow sublittoral zone,
which includes much of the sand to cobble shoreline and embayments in this
region; 14 (25%) feed in the salt marsh and mudflat environments character-
istic of large estuaries or contained embayments; 11 (20%) feed in neritic
waters; 4 (7%) obtain their prey on relatively exposed sand-gravel beaches;
3 (5%) utilize the fauna of the rocky littoral environment or the adjacent
kelp bed fauna; and 4 (7%) gulls have to be essentially universal to almost
all of these habitats.
Species Accounts
Arctic Loon
Arctic loons occur in north Puget Sound between October and May,
primarily as migrants and winter residents (Jewett, et al., 1953; Alcorn 1971;
214
-------
Table C-l. Relative abundance of marine and shore birds known to the
northern Puget Sound and Strait of Juan de Fuca area.
A = abundant, C = common, NC = not common, R = rare;
asterisk denotes seasonal occurrence.
Scientific name
Common name
Abundance
Order Gaviiformes
Gavia avctioa
G. irnner
G. stellata
Order Podicipediformes
Family Podicipedidae
Aechniophorus occidentalis
Podiaeps auritus
P. grisegena
P. nigrioollis
Order Procellariiformes
Family Procellariidae
Filmarus glacialis
Puff inns griseus
Family Hydrobatidae
Oceanodroma leucorhoa
Order Pelecaniformes
Family Phalacrocoracidae
Phalacroaorax penicillatus
P. auritus
P. pelagieus
Order Anseriformes
Family Anatidae
Branta aanadensis
B. nigvicans
Anser albifrons
Chen hyperborea
Anas platyrhynchos
A. aeuta
A. olypeata
A. carolinensis
Mareea americana
Aythya valisineria
A. marila
A. af'finis
Arctic loon C*
common loon C
red-throated loon C*
grebes
western grebe A
horned grebe C*
red-necked grebe C*
eared grebe C*
fulmars
fulmar NC
sooty shearwater NC
storm petrel
Leach's petrel NC
cormorants
Brandt's cormorant C*
double-crested cormorant C
pelagic cormorant C
waterfowl
Canada goose C*
black brant A*
white-fronted goose NC*
snow goose C*
mallard A*
pintail C*
northern shoveler C*
green-winged teal NC*
American widgeon C*
canvasback NC*
greater scaup NC*
lesser scaup A*
215
-------
Table C-l. Relative abundance of marine and shore birds known to the
northern Puget Sound and Strait of Juan de Fuca area.
A = abundant, C = common, NC = not common, R = rare;
asterisk denotes seasonal occurrence, continued.
Scientific name
Common name
Abundance
Buaephala olangula
B. islandiea
B. albeola
Clangula hyemlis
Histrionicus histrionicus
Melanitta deylandi
M. perspicillata
M. nigra
Family Anatidae
Mergus merganser1
M. sernaton
Order Falconiformes
Family Pandionidae
Pond-ion halinetus
Family Accipitridae
Aalineetus leuooaephalus
Order Ciconiiformes
Family Ardeidae
Ardea herodias
Order Gruiformes
Family Rallidae
Rallus limicola
Fulica americana
Order Charadriiformes
common goldeneye C*
Barrow's goldeneye C*
bufflehead C*
oldsquaw C*
harlequin duck NC*
white-winged scoter C*
surf scoter A
black scoter NC*
mergansers
common merganser C
red-breasted merganser C*
ospreys
osprey NC
kites, hawks, eagles
bald eagle C
herons, bitterns
great blue heron
rails, gallinules, coots
Virginia rail R
American coot C
Family Haematopodidae
Haematopus baohmani
Family Charadriidae
Charadrius semipalmatus
Family Scolopacidae
Numenius phaeopus
Actitis macularia
HeteYOScelus inccmwn
Limnodromus griseus
L. soolopaoeus
Aphriza virgata
oystercatchers
black oystercatcher C
plovers, surfbirds,
turnstones
semipalmated plover NC*
sandpipers
whimbrel C
spotted sandpiper A*
wandering tattler NC*
short-billed dowitcher C
long-billed dowitcher C
surfbird C*
216
-------
Table C-l. Relative abundance of marine and shore birds known to the
northern Puget Sound and Strait of Juan de Fuca area.
A = abundant, C = common, NC = not common, R = rare;
asterisk denotes seasonal occurrence, continued.
Scientific name
Common name
Abundance
Arenaria interpres
A. melanocephala
Tringa melanoleuoa
Calidris ptilocnemis
C. alpina
C. aanutus
C. minutilla
Ereunetes mauri
Crocethia alba
Family Phalaropodidae
Phalaropus tricolor
Lobipes lobatus
ruddy turnstone
black turnstone
greater yellowlegs
rock sandpiper
dunlin
knot
least sandpiper
western sandpiper
sanderling
phalaropes
Wilson's phalarope
northern phalarope
NC*
C*
C*
NC*
C*
C
C
A
C*
NC*
NC*
Family Stercorariidae
Stevoovarius parasiticus
S. pomarinus
Family Laridae
Larus glauceseens
L. occidentalis
L. nurgentatus
L. californicus
L. delawarensis
L. oanus
L. heermanni
L. Philadelphia
Xema sabini
Rissa tridactyla
Sterna hirundo
S. paradisnea
Hydroprogne aaspia
Family Alcidae
Uria aalge
Cepphus oolumba
Lunda airrhata
Cerorhinea monocerata
Ptyahoramphus aleutica
jaegers, skuas
parasitic jaeger
pomarine jaeger
gulls
glaucous-winged gull
western gull
herring gull
California gull
ring-billed gull
mew gull
Heermann's gull
Bonaparte's gull
Sabine's gull
blacklegged kittiwake
common tern
Arctic tern
Caspian tern
alcids
common murre
pigeon guillemot
tufted puffin
rhinoceros auklet
Cassin's auklet
C*
NC*
A
C*
C
C*
C*
C*
C*
A
NC
C*
C*
C*
C*
C*
C
C
A
R
Synthliboramphus antigiam
Brachyramphus mamoratum
ancient murrelet
marbled murrelet
C*
C
217
-------
Table C-2. Functional feeding groups and representative prey taxa of 58 marine and shore birds
common to northern Puget Sound and the Strait of Juan de Fuca.
Habitat
Trophic position
Predator species
Prey taxa
Offshore neritic
Obligate piscivore
Common murre
Black-legged kittiwake
Common tern
Rhinoceros auklet
Western grebe
10
H
oo
Facultative piscivore
Tufted puffin
Marbled murrelet
Ancient murrelet
Obligate planktivore
Cassins auklet
Northern anchovy
Eulachon
Pacific herring
Pacific sand lance
Juv. rockfish
Juv. Pacific salmon
Surf smelt
Night smelt
Walleye pollock
Threespine stickleback
Pacific sand lance
Pacific herring
Surf smelt
Northern anchovy
Rockfish
Shiner perch
Juv. rockfish
Sea urchins
(Strongylocentrotus sp.)
Bivalve molluscs
(Mytilus sp.)
Euphausiids
Calanoid copepods
(Calanus sp.)
Hyperiid amphipods
(Parathemisto sp.)
Euphausiids
-------
Table C-2. Functional feeding groups and representative prey taxa of 55 marine and shore birds
common to northern Puget Sound and the Strait of Juan de Fuca, continued.
Habitat
Trophic position
Predator species
Prev taxa
Facultative planktivore Mew gull
Bonaparte's gull
Parasite
Nearshore kelp beds Facultative avivore
Obligate piscivore
Facultative piscivore
Parasitic jaeger
Bald eagle
Brandt's cormorant
Heermann's gull
Arctic tern
Euphausiids
Hyperiid amphipods
Pacific herring (larv.?)
Pacific sand lance
(larv.?)
Foods of gulls and terns
Gulls
Pigeon guillemots
Cormorants
Puffins
Pacific herring
Pacific salmon
Dolly Varden
Cutthroat trout
Flatfishes
Sculpins
Sea urchins
Crabs (Pugettia producta)
Redtail surfperch
Kelp greenling
Black rockfish
Cabezon
Pacific sand lance
Pacific herring
Pacific sand lance
-------
Table C-2. Functional feeding groups and representative prey taxa of 55 marine and shore birds
common to northern Puget Sound and the Strait of Juan de Fuca, continued.
Habitat
Trophic position
Predator species
Prey taxa
Inshore rocky littoral Obligate benthivore
Black oystercatcher
Whimbrel
Black turnstone
ho
o
Inshore sand-gravel
beaches
Obligate benthivore
Spotted sandpiper
Surfbird
Least sandpiper
Sanderling
Nearshore Obligate piscivore
shallow sublittoral
Double-crested cormorant
Red-necked grebe
Common merganser
Limpets
Collisella digitalis
Notoacmea scutum
Aamea mitra
Chitons
(Katharina tunioata)
Bivalve molluscs
Mytilus edulis
M. oalifornianus
Barnacles
(Pollioipes polymerus)
Polychaete annelids
(Nereis sp.)
Polychaete annelids
Nereis sp.
Streblospio benedicti
Eteone longa
Amphipods
Anigogarmarus conferrico lus
Corophium sp.
Orchestoidea pugettensis
Bivalve molluscs
Univalve molluscs
Penpoint gunnel
Crescent gunnel
Pacific sand lance
Shiner perch
Snake prickleback
Staghorn sculpin
Pacific herring
Juv. Pacific salmon
Northern anchovy
-------
Table C-2. Functional feeding groups and representative prey taxa of 55 marine and shore birds
common to northern Puget Sound and the Strait of Juan de Fuca, continued.
Habitat
Trophic position
Predator species
Prey taxa
Facultative piscivore
Arctic loon
Common loon
Red-throated loon
Pelagic cormorant
Pigeon guillemot
Red-breasted merganser
Caspian tern
ro
ro
Obligate planktivore
Facultative benthivore
Eared grebe
Lesser scaup
Common goldeneye
Bufflehead
Oldsquaw
Surf scoter
Crescent gunnel
Pacific sand lance
Penpoint gunnel
Staghorn sculpin
Northern clingfish
Snake prickleback
Pacific herring
Surf smelt
Black prickleback
Threespine prickleback
Juv. flatfish
(Pleuronectidae)
Snake prickleback
Shrimp
Spirontocopis
brevirostris
Crago alaskensis
Pandalus sp.
Crabs
(Hemigrapsis sp.)
Mysids
Amphipods
Bivalve molluscs
Tapes japonica
Ostrea lurida
Mytilus edulis
Mya arenaria
Maooma sp.
Crustaceans
Fish
Pacific herring eggs
Eelgrass (.Zoetez-a sp.)
-------
Table C-2. Functional feeding groups and representative prey taxa of 55 marine and shore birds
common to northern Puget Sound and the Strait of Juan de Fuca> continued.
Habitat
Trophic position
Predator species
Prey taxa
Inshore, saltmarsh
and mudflats
Obligate herbivore
Canada goose
Black brant
Snow goose
American coot
Omnivore,
Facultative herbivore
ro
to
Mallard
Pintail
Northern shoveler
American widgeon
Omnivore
Dunlin
Knot
Western sandpiper
Eelgrass (Zostera sp.)
Saltmarsh plants
Saliaornia sp.
Distichlis spiaata
Cuscuta salina
Trigloahia maritimwn
Canex lyngbyei
Eelgrass (Zostera sp.)
Saltmarsh plants, seeds
Saliaornia sp.
Trigloahia maritinum
Canex lyngbyei
Amphipods
(An is ogcanmarus
eonfervioolus)
Insect larvae
(Aphrosylus sp.)
Saltmarsh plants, seeds
Spevgularia marina
Triglochia maritinwn
Deschampsia oespitosa
Amphipods
Covophiim sp.
Anisogarmarius conferviaolus
Orahestoidea pugettensis
Amphitoe sp.
Polychaete annelids
Nereis sp.
Streblospio benediati
Amphioteis mucronata
Eteone lonqa
-------
Table C-2. Functional feeding groups and representative prey taxa of 55 marine and shore birds
common to northern Puget Sound and the Strait of Juan de Fuca, continued.
Habitat
Trophic position
Predator species
Prey taxa
NJ
NJ
Obligate piscivore
Obligate benthivore
Great blue heron
Shcrt-billed dowitcher
Long-billed dowitcher
Facultative benthivore
Greater yellowlegs
Oligochaetes
Bivalve molluscs
Maaoma inaonspiaua
Mya arenaria
Tanaids
(Pancolus californiensis)
Nematodes
Staghorn sculpin
Starry flounder
Shiner perch
Penpoint gunnel
Polychaete annelids
(Nereis sp.)
Univalve molluscs
Nassariidae
Littorina sp.
Bivalve molluscs
(Mytilus edulis)
Crabs
Shrimp
Isopods
(Exosphaevoma oregonensis)
Amphipods
Corophiufn spinicorne
Eahinogammarus oohotensis
Molluscs
Crustaceans
Fish
-------
Table C-2. Functional feeding groups and representative prey taxa of 55 marine and shore birds
common to northern Puget Sound and the Strait of Juan de Fuca, continued.
Habitat
Trophic position
Predator species
Prey taxa
Universal
Facultative benthivore
Glaucous-winged gull
Western gull
California gull
Ring-billed gull
SJ
Chitons
Starfish
Sea cucumbers
Sea urchins
(Strongyloaentrotus sp.)
Crabs
Cancer sp.
Hemigrapsus sp.
Bivalve molluscs
Mytilus edulis
Clinocardium nuttalli
Polychaete annelids
(Nereis sp.)
Pacific herring
Northern anchovy
Surf smelt
Pacific herring eggs
Cormorant fledglings
Murre fledglings
-------
Salo 1975). They are quite common in the San Juan Islands, often in large
aggregations (up to 1,000) during migration (Salo 1975; Heilbrum, et al.,
1977). When on marine waters arctic loons are assumed to eat fish, crusta-
ceans, and molluscs (Martin, et al., 1951; Salo 1975).
Common Loon
The only year-round resident loon, common loons tend to be more abundant
in marine habitats during winter, though seldom in as large concentrations as
arctic loons (Jewett, et al., 1953; Alcorn 1971; Salo 1975). Wintering
common loons appear to feed primarily on fish (Martin, et al., 1951; Jewett,
et al., 1953). Salo (1975) reported a common loon preying on small 10-13 cm
flounders off Sandy Point, Whidbey Island.
Red-Throated Loon
Red-throated loons, the least common of the three loon species, are
migrants and winter residents in north Puget Sound, and occur in aggregations
of up to 100 birds. They appear to be fairly abundant in the San Juan
Islands (Jewett, et al., 1953; Alcorn 1971; Salo 1975). Jewett, et al.
(1953), and Martin, et al. (1951), reported the generalized diet of red-
throated loons as including fish, crustaceans, molluscs, fish eggs, leeches,
insects, and some aquatic vegetation.
Western Grebe
Overall, western grebes were the most abundant of the species observed
in Manuwal's (1977) seven transect surveys in the San Juan Islands conducted
from ferries between November 1973 and April 1974. They appear primarily as
wintering populations, although some non-breeding birds may reside in Puget
Sound through the summer (Jewett, et al., 1973; Salo 1975). Fish are the
primary prey organisms of western grebes (Munro 1941a; Jewett, et al., 1953;
Phillips and Carter 1957; Salo 1975). Species which have been identified as
prey include Pacific herring (Clupea harengus pallasi), especially during
spawning periods, staghorn sculpin (Leptocottus armatus) and other sculpins,
shiner perch (Cymatogaster aggregata), and smelt (Osmeridae). Shrimp
(Pandalus goniurus) were also reported as prey.
Horned Grebe
Breeding horned grebes are common migrants on Puget Sound in winter,
typically from September through May, and a few non-breeding birds occur in
summer (Munro 1941a; Jewett, et al., 1953; Bakus 1965; Salo 1975). In
Manuwal's (1977) ferry transect surveys through the San Juan Islands, they
were observed to be numerous only once, in January 1974. Fish (Pacific sand
lance, Ammodytes hexapterus, Pacific herring, and staghorn sculpin) and small
shrimp (Spirontocaris brevirostris. Crago alaskensis. and Pandalus sp.) and
crabs (Hemigrapsis sp.) appear to be most important to the horned grebe
feeding on marine waters (Munro 1941a; Guiguet 1971b).
225
-------
Red-Necked Grebe
Of the species of grebes frequenting Puget Sound, the red-necked grebe
is probably the least abundant. It follows the same pattern of occurrence,
however, residing as a winter migrant between November and May (Munro 1971a;
Jewett, et al., 1958; Salo 1975). It occurred in abundance during two of
Manuwal's (1977) San Juan Island ferry transect surveys, in January and April
1974. Spawning Pacific herring, Pacific sand lance, pilchard (Sardinops
caerulea?), threespine stickleback (Gasterosteus aculeatus), blenny (Pholidae
and Stichaeidae?), and sculpin (Cottidae) have been reported as food organisms
(Munro 1941a; Guiguet 1971b; Salo 1975).
Eared Grebe
Like the other grebes, eared grebes are mainly winter migrants, and are
similar to horned grebes in distribution and abundance (Jewett, et al., 1953;
Salo 1975; Heilbrum, et al., 1977). They did not appear in significant
numbers, however, during Manuwal's (1977) ferry transect surveys through the
San Juan archipelago. Unlike the other grebes, eared grebes feeding in marine
habitats eat planktonic crustaceans—mysids and amphipods (Munro 1941a).
Fulmar
Jewett, et al. (1953), and Sanger (1965, 1970) provide indications and
data that fulmars are generally abundant in nearshore areas along the
Washington coast in fall (September-October), although it appears that their
incidence inside the Strait of Juan de Fuca is rare. Martin (1942) suggested
that fulmars were apparently more abundant off the northwest coast of
Vancouver Island in winter.
Sanger and Baird (1977) listed fish (70% frequency of occurrence), squid
(70%), and crustaceans (20%) as the principal prey of fulmars collected in
Alaskan waters between 1969 and 1976. Fulmars collected in April from along
the Bering Sea icepack had consumed only squid.
Sooty Shearwater
Sooty shearwaters appear in the region's offshore waters between March
and October (Martin 1942) but seldom occur in nearshore waters (Dr. Dave
Manuwal, Univ. Washington, pers. comm.). Anchovies (Engraulidae) contributed
80% of the diet by volume of sooty shearwaters off Oregon, and other fishes
and squid provided the difference, as reported by Wiens and Scott (1975) who
calculated their total annual energy demand to equal 1.653 k cal m~2.
Feeding off northwest Vancouver Island was observed to include Pacific sand
lance and euphausiids (Martin 1942). Sanger and Baird's (1977) account of
the major food items of sooty shearwaters collected in Alaskan waters between
1967 and 1976 indicated that fish occurred in 61% and squid in 46% of the
stomachs examined.
Leach's Petrel
Martin (1942) described the Leach's petrel as the second most frequently
seen bird in offshore areas from February through June, though never in high
226
-------
abundance. Sanger (1970), however, reported this species as the least
abundant and least frequently seen during his surveys. According to
Manuwal's (1977) surveys, 3,655 pairs of Leach's petrels were breeding on the
outer coast of Washington, centered at Carroll Island; their occurrence^
inside the Strait of Juan de Fuca is rare, however. In Wiens and Scott's
(1975) energy modeling study, hydrozoa and euphausiids were listed as the
principal dietary components by percent volume for Leach's petrel. The model
output predicted a total annual energy demand of 0.106 k cal m~2 for this
species, the lowest estimate of the four species modeled.
Brandt's Cormorant
The majority of Brandt's cormorants appear to migrate into the north
Puget Sound region from California breeding colonies between October and
April, peak abundance occurring between November and February (Wahl 1977).
Breeding colonies of 20 to 50 mating pairs, however, do occur on the outer
coast at Point Grenville, Grenville Arch, Willoughby Rock, and Quillayute
Needles (Manuwal 1977); these birds may constitute many of those feeding in
the western Strait of Juan de Fuca. The 1976 Audubon Christmas bird count
(Heilbrum, et al., 1977) reported 479 sightings at Victoria, B.C., 438 at
Fender Islands, B.C., 12 in the San Juan Islands, 110 at Bellingham, and 15
in the Sequim-Dungeness area.
Gabrielson and Jewett's (1940) account of Brandt's cormorant in Oregon
listed "trash fish" as the primary food. Scott's (1973) data indicated that,
on the basis of percentage of stomach contents volume, anchovy, rockfish
(Scorpaenidae), sculpin, and other fishes contribute equally to the Brandt's
cormorant diet off Oregon in summer; in winter, rockfish, sculpin, and other
fishes make up the diet. Using these data, Wiens and Scott (1975) determined
that the total annual energy demand for this species was 2.308 k cal m~2,
second highest of the four species that they modeled.
Hubbs's, et al. (1970), account of the diverse prey spectrum of Brandt's
cormorants feeding in southern California indicated that they typically
foraged in Macrocystis kelp beds where they captured midwater fishes (black-
smith, Chromis punctipinnis, senorita, Oxyjulis californica, white seaperch,
Phanerodon atripes, kelp perch, Brachyistius frenatus, and vermillion rock-
fish, Sebastes miniatus). Over sand bottoms, the diving birds utilized
various species of flatfish (speckled sanddab, Citharichthys stigmaeus,
fantail sole, Xystreurys liolepis, and curlfin turbot, Pleuronichthys
decurrens) and roughback sculpin, Chitonotus pugetensis.
Martini (1966) suggested that the fish otoliths in the pellets regurgi-
tated by western gulls actually originated from fish captured by Brandt's
cormorants. These fish included Pacific hake (Merluccius productus), Pacific
sanddab (Citharichthys sordidus), pink seapearch (Zalembius rosaceus), short-
belly rockfish (Sebastes jordani), sculpin (Icelinus sp.), and blackeye goby
(Coryphopterus nicholsi) which may be taken at depths of 20 to 50 m or more
(Hubbs, et al., 1970).
Sculpin (including cabezon, Scorpaenichthys marmoratus). juvenile rock-
fish, and greenling (Hexagrammidae) were the principal prey taxa consumed by
227
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Brandt's cormorants off Oregon, except in mixed-species flocks when they fed
on northern anchovy and "smelt" (Scott 1973); surfperches (Embiotocidae) were
also observed in their beaks.
These data would tend to indicate that Brandt's cormorants feeding in
north Puget Sound and the Strait of Juan de Fuca would also prey upon
rocky/kelp bed fishes, which probably would include redtail surfperch
(Amphistichus rhodoterus), kelp greenling (Hexagrammos decagrammus), white-
spotted greenling (H. stelleri), several rockfish species, Pacific herring,
and Pacific sand lance.
Double-Crested Cormorant
Manuwal (1977) estimated 390 nesting pairs on Washington's outer coast
and 64 pairs in the San Juan Islands and the Strait of Juan de Fuca; the most
numerous populations were located at Bird Rocks and Viti Rocks.
Robertson's (1974) report of food organisms regurgitated by double-
crested cormorant chicks in British Columbia included 11 fishes of which
gunnels (Apodichthys flavidus and Pholis laeta) were the most important
(46.6% total prey abundance, 51.6% total prey weight), followed by Pacific
sand lance (20.5%, 4.6%), shiner perch (15.5%, 20.5%), snake prickleback
(Lumpenus sagitta, 11.5%, 10.2%), staghorn sculpin (2.7%, 5.9%), Pacific
herring (1.4%, 2.7%), threespine stickleback (0.4%, 0.1%), juvenile salmon
(Oncorhynchus sp., 0.2%, 0.9%), and northern anchovy (Engraulis mordax, 0.2%,
0.1%).
Unidentified crustaceans occurred in the one stomach sample listed by
Sanger and Baird (1977). Scattergood's (1950) analysis of the contents from
35 stomachs collected in Maine included demersal fishes, primarily cunner
(Tautogolabrus adspersus, 35.2% of total abundance of identifiable prey),
shorthorn sculpin (Myoxocephalus scorpius) and longhorn sculpin (M. octodeci-
mospinosus, 11.1% each), redfish (Sebastes marinus, 9.3%), Atlantic herring
(Clupea harengus, 7.4%), winter flounder (Pseudopleuronectes americanus, 7.4%),
rock gunnel (Pholis gunnellus, 7.4%), and alewife (Alosa pseudoharengus, 5.6%).
Rock gunnel, winter flounder, cunner, and pollock (Pollachius virens) were
the predominant fish regurgitated by chicks at the White Islands, Maine,
rookery in early July, whereas in early August silversides (Meniclia notata)
suddenly became predominant, followed by cunner, redfish, and rock gunnel.
Pelagic Cormorant
Pelagic cormorants are the most abundant of the nesting cormorants in
the region. Manuwal (1977) listed 995 pairs in the population breeding along
the outer coast and 395 pairs in the inland waters of the San Juan Islands
and the Strait of Juan de Fuca. Included in the latter estimate are large
colonies at Protection Island, Viti Rocks, Williamson Rocks, Bare Island, and
Colville Island.
Pelagic cormorants' prey reported by Robertson (1974) included shrimp
(19.4% prey abundance, 6.8% prey weight), and six species of fish: Crescent
gunnel (Pholis laeta, 34.9%, 37.1%), Pacific sand lance (31.1%, 18.9%),
228
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penpoint gunnel (Apodichthys flavidus. 4.9%, 11.1%), staghorn sculpin (2.9%,
13.2%), northern clingfish (Gobiesox maeandricus, 2.9%, 5.6%), and snake
prickleback (3.9%, 7.3%). It was also suggested that prey size was larger
for pelagic cormorants than for double-crested cormorants.
Sculpins (Myoxocephalus sp.) were the only identifiable prey organisms
taken by pelagic cormorants collected off Yaquina Head, Oregon, although
these birds were also observed eating northern anchovy and "smelt" while
feeding in large mixed-species flocks, and benthic crustaceans while feeding
singly. Palmer (1962) listed demersal fishes (sculpin, greenling, pholids,
poacher, Agonidae, and flatfish) and midwater fishes (Pacific herring and
Pacific tomcod, Microgadus proximus) as the principal food organisms found in
31 stomachs collected in Alaska.
Canada Goose
Canada geese are both winter migrants and residents along the Washington
coast, specifically during March through April and September to October.
Although migrating flocks are composed of thousands of birds, wintering flocks
are small, less than 100 individuals (Salo 1975). The 1976 Audubon Christmas
bird count recorded as many as 515 Canada geese at Vancouver, B.C., 87 at
Victoria, B.C., 54 at Nanaimo, B.C., and a few individuals at Sequim-Dungeness,
Bellingham, and Everett, Washington (Heilbrum, et al., 1977). Martin, et al.
(1951), cites the diet of wintering Canada geese in this region to include
primarily reeds and the vegetative parts of barley, bulrush, and hardstem,
and secondarily wheat, wild barley, and bromegrass. When Canada geese fre-
quent marine shoreline habitats, however, eelgrasses (Zostera sp.) and salt-
marsh plants (e.g., Salicornia sp., Distichlis spicata, Cuscuta salina, and
Triglochin maritimum) may also enter their diet.
Black Brant
Black brant frequent the north Puget Sound region throughout the winter
and spring, both as migrants and local winter residents, but they appear to
be most abundant in March and April (Jewett, et al., 1953; Einarsen 1965;
Salo 1975). The principal wintering sites include Padilla Bay, Samish Bay,
Discovery Bay, and Sequim Bay. In April, as many as 18,000 birds have been
recorded in Samish Bay, 55,000 in Padilla Bay, and 6,000 in Discovery Bay
(Salo 1975; D. Moriarity and S. Oliver, Graysmarsh Wildl. Ref., pers. comm.;
R.R. Parker, Wash. Dept. Game, unpubl. data). The 1976 Audubon Christmas
bird count (Heilbrum, et al., 1977) included black brant sightings all over
the north Puget Sound and Strait of Juan de Fuca region but in abundance
only at Sequim-Dungeness. Eelgrass is the main component of the black
brant's diet, augmented slightly by ulvoid algae (Einarsen 1955; Salo 1975).
White-Fronted Goose
White-fronted geese occur as migrants during the fall migration
especially in September, along the northern Olympic Peninsula in areas such
as Dungeness Bay (Salo 1975). The only diet information is from the Califor-
nia wintering grounds where rice, vegetative parts and seeds of grasses
sedges, and wild millet, and barley were the most important foods (Martin,
229
-------
et al., 1951). Hence, they resemble Canada geese in their foraging and may
utilize similar food sources—e.g., saltmarsh plants and eelgrasses—when
feeding in estuarine habitats of this region.
Snow Goose
Like black brant, snow geese frequent the estuaries of northern Puget
Sound as migrants and as local winter residents. Thus, their peak abundance
occurs twice, in November and again in April (Jeffrey 1950; Jewett, et al.,
1953; Alcorn 1971; Salo 1975). Contrary to the brant distribution, snow
geese tend to congregate on the east side of Puget Sound, especially in
Padilla Bay, Skagit Bay, and Port Susan, reaching maximum densities of 27,000
to 30,000 geese. They are reported to maintain local movements between these
areas and the Fraser River delta, British Columbia (D. Manuwal, pers. comm.).
Marsh plants, especially the roots and bulbs, are their principal food items
when foraging in the estuary (Jeffrey 1950; Jewett, et al., 1953; Salo 1975).
Mallard
The most common of the game ducks taken recreationally in Washington,
the mallard occurs mostly in freshwater habitats, but also frequents
estuarine habitats, principally between November and April (Munro 1943;
Jewett, et al., 1953; Alcorn 1971). The largest concentrations in north
Puget Sound appear to be at Dungeness Bay (4,000-5,000 individuals), and the
region encompassing Padilla Bay, Samish Bay, Skagit Bay, and Port Susan
(19,500-44,000) (Salo 1975). Mallards collected from Grays Harbor on
Washington's outer coast were feeding mainly on seeds of saltmarsh plants
(including Triglochin maritimum) and incidentally on polychaete annelid
worms (Smith and Mudd 1976).
Pintail
Pintails occur concurrently with American widgeons, principally in the
upper tideflat regions of estuaries, as a fall and spring migrant, and
probably do not represent a significant breeding population (Munro 1944;
Jewett, et al., 1953; Alcorn 1971; Salo 1975). Dungeness Bay and the eastern
shore between Port Susan and Boundary Bay tend to exhibit the highest concen-
trations of pintails (Salo 1975). Skagit Bay undoubtedly has the greatest
numbers, up to 52,300 birds in October. Padilla Bay is also an important
feeding area, with 13,000 to 15,000 birds in October-November (R.C. Parker,
Washington Dept. Game, unpub. data). Smith and Mudd (1976) provided an
indication of a diverse diet spectrum for pintails foraging in estuarine
habitats at Grays Harbor, including eelgrass, seeds of the saltmarsh grasses
Carex lyngbyei and Triglochia maritimum, amphipods (Anisogammarus confervi-
colus), and insect larvae (Aphrosylus sp.)-
Northern Shoveler
Northern shovelers occur in flocks of 20 to 500 birds on sheltered
estuaries and embayments between September and May (Kortright 1942; Jewett,
et al., 1953; Salo 1975). They were sighted throughout the region during the
1976 Audubon Christmas bird count (Heilbrum, et al., 1977) but Victoria,
230
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B.C. (98 birds), and Bellingham, Washington (58 birds), had the greatest
counts. Kortright (1942), Martin, et al. (1951), and Salo (1975) described
the diet of northern shoveler as 65% plant matter—pondweed, sedge, and grass
seeds—and 34% invertebrates, 19% of which were gastropod molluscs.
Green-Winged Teal
A common game bird in Washington's freshwater habitats, green-winged
teal are also common in the upper estuarine habitats of the State. They are
particularly abundant in the mud/eelgrass estuarine habitats along the
eastern shoreline of Puget Sound, including Skagit Bay (max. of approximately
25,000 in October), Port Susan (max. of 13,700 in December), Padilla Bay
(max. of 2,500 in November), and Samish Bay (max. of 5,100 in October) (R.C.
Parker, Washington Dept. Game, unpub. data). Smith and Mudd (1976) listed
invertebrates—amphipods (Anisogammarus confervicolus) and insect larvae
(including Sanderia sp. and Manayunkia sp.)—as the major prey items of
green-winged teal collected from mudflat habitats in upper Grays Harbor.
American Widgeon
American widgeons utilize the upper tideflat habitats of most of the
major estuaries of coastal Washington and Puget Sound in winter. At that
time (October to April) they usually are the most common duck on the region's
marine waters (Salo 1975). Port Susan, Skagit Bay, Samish Bay, and Padilla
Bay tend to support the largest concentrations, peak abundances of 32,000 to
39,000 occurring in October-November (R.C. Parker, Wn. Dept. Game, unpub.
data). October-November was also the period of maximum abundance (3,500)
observed at Sequim Bay, although counts usually stayed above 1,000 until
after March (D. Moriarity and S. Oliver, Graysmarsh Wildlife Refuge, pers.
comm.). The 1976 Audubon Christmas bird count (Heilbrum, et al., 1977)
reported the greatest number of sightings in north Puget Sound at Victoria
(8,201) and Vancouver (3,978) in British Columbia, and Bellingham, Washington
(1,014). Widgeons examined from four sites in upper Grays Harbor had been
feeding principally upon eelgrass and dwarf European eelgrass, "L_. nolti
(Smith and Mudd 1976). ~
Canvasback
Northeast Puget Sound bays and estuaries, including Drayton Harbor,
Birch Bay, Padilla Bay, and Samish Bay, are the principal areas of canvasback
concentrations, where peak abundances of up to 1,000 are reached in November
(Jewett, et al., 1953; Salo 1975; R.C. Parker, Wn. Dept. Game, unpub. data).
The eastern Strait of Juan de Fuca may also harbor some winter residents,
especially at Dungeness Bay and Victoria, B.C. (Salo 1975; Heilbrum, et al.,
1977). Jewett, et al. (1953), indicate that eelgrass and marine polychaete
annelids and crustaceans constitute the canvasback's diet.
Greater Scaup
The Strait of Georgia and northern Puget Sound harbor concentrations of
winter migrant and resident greater scaup from December to February (Munro
1941b; Jewett, et al., 1953; Salo 1975). Relatively high abundances were
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enumerated at Vancouver, B.C. (1,067), and Bellingham, Washington (1,055),
during the 1976 Audubon Christmas bird count (Heilbrum, et al., 1977).
Padilla Bay, where peak abundances occurred of approximately 2,700 birds,
appears to harbor the highest concentrations in north Puget Sound (R.C.
Parker, Wn. Dept. Game, unpub. data), although Munro (1941b) reported as
many as 8,000 in one flock. Manuwal (1977) listed greater scaup as the
third most abundant diving species observed during his seven ferry transect
surveys through the San Juan archipelago.
Littoral and shallow sublittoral molluscs and crustaceans appear to
constitute the diet of greater scaup foraging in marine environments (Salo
1975), although these birds are also reported to congregate near spawning
Pacific herring in March and April (Munro 1941b). Martin and Uhler (1939)
listed the native oyster, Ostrea lurida, along the Washington coast as one of
the principal food items of greater scaup.
Lesser Scaup
Salo (1975), using information from Munro (1941b), Jewett, et al. (1953),
Bakus (1965), and Alcorn (1971), suggests that lesser scaup are distributed
mainly in freshwater habitats during their winter residency in northern Puget
Sound; several sources, however, had documented lesser scaup occurring
commonly on the region's marine waters. The 1976 Audubon Christmas bird
count (Heilbrum, et al., 1977), in fact, included high counts at both
Vancouver (452) and Victoria (1,012), B.C. Although preference for aquatic
and marsh plants was shown by Munro (1941b) and Martin, et al. (1951), the
diet of lesser scaup in marine waters may, like greater scaup, be oriented
toward invertebrates such as molluscs and crustaceans (Rogers and Korschgen
1966).
Common Goldeneye
Common goldeneye was considered a common migrant and winter resident by
Munro (1939), Jewett, et al. (1953), and Salo (1975). These birds typically
occur in the channels and small bays in flocks of 20 to 30 individuals, often
in association with other diving ducks. Drayton Harbor and Birch Bay in
northeast Puget Sound appear to harbor the greatest wintering abundance of
any of the sites surveyed by the Washington Department of Game in north Puget
Sound and the Strait of Juan de Fuca (R.C. Parker, Wash. Dept. Game, unpubl.
data). Kortright's (1942) analysis of 395 common goldeneye stomachs indi-
cated that crustaceans (32%) and insects (28%) were the major prey taxa,
followed by molluscs (10%) and plant (pondweed 9%) remains.
Barrow's Goldeneye
Generally thought less abundant than the common goldeneye, Barrow's
goldeneye are similarly distributed as migrants and winter residents through-
out the north Puget Sound region (Munro 1939; Alcorn 1971; Salo 1975).
Populations wintering in the Strait of Georgia may be more numerous, as
evidenced by the 1976 Audubon Christmas bird count (Heilbrum, et al., 1977),
wherein over 2,000 individuals were counted at Nanaimo, B.C., and 1,269 at
Vancouver, B.C. Insects (36%), and especially molluscs (19%) and crustaceans
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(18%), are important food taxa for Barrow's goldeneye occupying marine
habitats (Kortright 1942; Salo 1975).
Bufflehead
Bufflehead appear to be widely distributed, abundant migrant and winter
residents, characterizing shallow, sheltered marine habitats (Munro 1942;
Jewett, et al., 1953; Erskine 1971; Salo 1975). They appear to be especially
concentrated in northeastern Puget Sound, where flocks of 3,800 to 12,800
birds are reported, and Dungeness Bay, where peak abundances of 4,600 birds
are recorded in December (Salo 1975). Abundances reported at Sequim Bay
peaked at over 300 during October-November and March but remained between
135 and 150 during the rest of the winter (D. Moriarity and S. Oliver,
Graysmarsh Wildlife Refuge, pers. comm.). The maximum counts in the 1976
Audubon Christmas bird count were at Victoria (1,198), Bellingham (656), and
Dungeness Bay (581) (Heilbrum, et al., 1977). In marine habitats, crusta-
ceans, molluscs, and to a lesser extent, small fish appear to be the most
important food items (Munro 1942; Salo 1975); herring eggs laid in shallow
sublittoral waters may also be consumed when available in the spring.
Oldsquaw
Also a migrant and winter resident, oldsquaw in Washington State occur
rather uniformly though sparsely throughout north Puget Sound and the Strait
of Juan de Fuca (Kortright 1942; Jewett, et al., 1953; Larrison and Sonnen-
berg 1968; Alcorn 1971; Salo 1975). Kortright (1942) listed crustaceans
(48%), molluscs (16%), insects (11%), and fish (10%) as the primary prey taxa
found in 227 stomachs. Like many of the other diving ducks, oldsquaw have
been observed foraging on the eggs of Pacific herring in the spring (Jewett,
et al., 1953).
Harlequin Duck
Harlequins appear to be one of the few diving ducks which are year-long
residents in the State, although many of those inhabiting Puget Sound in
winter may include migrants (Jewett, et al., 1953; Alcorn 1971; Salo 1975).
They occur in congregations of up to 200 birds along rocky shores of the San
Juan Islands, Dungeness Spit and Bay, and along the northern shore of the
Olympic Peninsula. Crustaceans (57%) and molluscs (25%) composed the diet of
64 harlequins examined by Kortright (1942, cited in Salo 1975).
White-Winged Scoter
A common and often the most abundant sea duck in winter in Washington's
inland and coastal waters, white-winged scoters have been estimated to number
up to 42,000 birds (Jewett, et al., 1953; Alcorn 1971; Salo 1975). Manuwal
(1977) reported this species as the second most abundant over all seven ferry
transect surveys conducted between November 1973 and April 1974 in the San
Juan Islands. They tend to be more abundant in the eastern Strait of Juan de
Fuca; approximately 400 are observed during October-November in Sequim Bay
and they are also common at Dungeness Spit (D. Moriarity and S. Oliver
Graysmarsh Wildlife Refuge, pers. comm.; 1977 Olympic Pen. Audubon Soc!
Christmas Count Newsletter, unpub.).
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One specimen collected in Grays Harbor had eelgrass in its esophagus
(Smith and Mudd 1976). Cottam (1939) described the stomach contents of 819
white-winged scoters collected in the Pacific Northwest. They contained 75%
bivalve molluscs (Manila clams, Tapes japonica, Olympia oysters, blue mussels,
and scallops), 13% crustaceans, and incidentally fish and insects. In Puget
Sound they have been observed foraging over shallow-water commercial clam
and oyster beds and on herring eggs (Jewett, et al., 1953; Salo 1975).
Surf Scoter
Surf scoters are generally similar to white-winged scoters in occurrence,
distribution, and abundance (Jewett, et al., 1953; Salo 1975). According to
the 1976 Audubon Christmas bird count, in fact, they were more numerous at
Nanaimo (1,943), Vancouver (2,160), Victoria (361), Bellingham (417), and
Everett (58) (Heilbrum, et al., 1977). Salo (1975) included reports of
2,400 to 3,000 birds at Dungeness Spit between September and November, 40,000
at Destruction Island in October, and 1,200 in the San Juan Islands in
December. Manuwal (1977) designated surf scoters as the sixth most numerous
diving species observed along his ferry transect surveys, winter 1973 to
spring 1974.
The prey of surf scoters examined by Cottam (1939) was primarily
molluscs (61%, 29% of which were blue mussels), crustaceans (10%), and
insects (10%). The stomachs of 21 surf scoters from Dabob Bay, Washington,
contained primarily Manila clams, but blue mussels and soft-shell clams, Mya
arenaria, and Macoma sp. clams also occurred (Glude 1967).
Black Scoter
Black scoters appear to be less abundant than the other two scoter
species, and tend to be distributed more along the exposed coast (Salo 1975).
Black scoters were sighted during the 1976 Audubon Christmas bird count in
the Strait of Georgia—e.g., Nanaimo (280) and Vancouver (342) (Heilbrum,
et al., 1977). October and May appear to be the peak fall and spring
migration periods (Kortright 1942). Cottam's (1939) analysis of the contents
of 124 black scoter stomachs indicated that 65% was molluscs (27% blue mussel,
7% razor clam, Siligua patula, 6% oysters, Ostrea lurida?, and 5% littleneck
clams), 17% crustaceans, and 3% insects. Glude (1967) identified Manila
clams, blue mussels, and barnacles (Balanus sp.) in the stomachs of scoters
feeding in Dabob Bay, Washington.
Common Merganser
Though common mergansers reside in terrestrial aquatic habitats through
the spring and summer, they congregate in marine and estuarine habitats
during fall and winter (Jewett, et al., 1953; Salo 1975). Nanaimo, Fender
Islands, Victoria, and Vancouver, B.C., all had between 100 and 200 sightings
during the 1976 Audubon Christmas bird count (Heilbrum, et al., 1977) and
300 have been sighted at Dungeness Spit (Salo 1975). Yet, little quantitative
diet information exists for the common merganser. It is assumed to dive for
and consume small fishes, apparently including juvenile salmon (Salo 1975).
Small demersal fishes (cottids, pholids, stichaeids, pleuronectids) and
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schooling neritic fishes (Pacific herring, Pacific sand lance) may also be
consumed.
Red-Breasted Merganser
The red-breasted merganser is more of a migrant and winter resident
than the common merganser. It occupies north Puget Sound waters between
September and April and reaches maximum abundance in November (Salo 1975).
As many as 125 birds were seen forming one premigration flock at Dungeness
Spit in April and 141 birds were observed there in December 1977 (1977
Olympic Pen. Audubon Soc. Christmas Count Newsletter, unpub.). Fish (sculpin
and Pacific herring) and crustaceans are important prey items for red-breasted
mergansers foraging in marine habitats, and they have been observed to
concentrate on spawning Pacific herring during February and March (Munro and
Clemens 1939; Kortright 1942; Salo 1975).
Osprey
Ospreys do not appear to frequent marine habitats of Washington, except
in the San Juan Islands where they occur from April to October (Retfalvi
1963; Bakus 1965). Fishes are generally considered to be the basic prey of
ospreys (Bent 1937; Salo 1975).
Bald Eagle
Although they do not actually occupy the marine waters, bald eagles at
times forage in the nearshore environment, and thus periodically appear as
upper trophic level consumers in those food webs. Of the 221 bald eagle
nests reported in a 1975 survey of western Washington (Grubb, et al., 1975),
47% (103 nests) were located in the San Juan Islands and 26% (57 nests) were
located in the northern section of the Olympic Peninsula; between 60% and 64%
of these nests were considered successful. Despite increased human activity
in the vicinity of nests on San Juan Island reported by Retfalvi (1965),
Newman, et al. (1977), reported a 100% increase in eagle nests between
1962-63 and 1975.
Although they commonly scavenge for food, bald eagles raid seabird
colonies, taking gulls, guillemots, cormorants, and puffins (Campbell 1969;
Salo 1975), and capture benthic invertebrates such as crabs (Pugettia
producta), sea urchins (Strongylocentrotus sp.), and abalone (Haliotis
kamschatkana), and fish, including salmon (Oncorhynchus sp.), Pacific herring,
Dolly Varden (Salvelinus malma), cutthroat trout (Salmo clarki), Pacific
halibut (Hippoglossus stenolepis). and sculpin (Hawbecker 1958; Campbell
1969; Ofelt 1975; Salo 1975).
Great Blue Heron
Commonly observed singly or in small groups in shallow waters of tide
flats and estuaries, great blue herons are distributed throughout north Puget
Sound and eastern Strait of Juan de Fuca (Bakus 1965; Salo 1975). In general,
great blue heron prey on aquatic and estuarine animals, including fish,
amphibians, and crustaceans, but also insects and small terrestrial mammals
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(Martin, et al., 1951; Jewett, et al., 1953; Lowe 1954; Meyerriecks 1962).
Those studied by Krebs (1974) on the Fraser River delta near Vancouver, B.C.,
had consumed either staghorn sculpin or starry flounder (Platichthys
stellatus), these two species accounting for 67% of all prey. Other
incidental prey were shiner perch, penpoint gunnel, and shrimp. Although
great blue heron typically forage in shallow waters, one was observed by
Godin (1977) to effectively capture 5-9 cm long shiner perch while standing
on a platform floating over 10 m of water.
Virginia Rail
These rather rare shorebirds are found on Pacific Northwest estuaries,
tideflats, and sand beaches in winter (Robbins, et al., 1966). Heilbrum,
et al. (1977), included reports of one Virginia rail each at Vancouver and
Victoria, B.C., during the December 1976 Audubon count. Little information
is available on their diet; it is assumed that, as in the diets of other
shorebirds, shallow-water crustaceans may be important.
American Coot
Coots are common resident birds in Washington and British Columbia which
winter in sheltered marine habitats (Jewett, et al., 1953; Alcorn 1971; Salo
1975). Large aggregations have been reported throughout north Puget Sound
and the Strait of Juan de Fuca, especially in the semi-urban areas near
Vancouver and Victoria, B.C., and Bellingham, Washington (Salo 1975; Heilbrum,
et al., 1977). The stomach of one American coot collected in Grays Harbor by
Smith and Mudd (1976) contained eelgrass and a small amount of algae.
Black Oystercatcher
Black oystercatchers are common residents of the coastal regions of
western Washington, usually frequenting the rocky exposed shoreline and
nesting on the islands and islets along the Pacific coast of the Olympic
Peninsula and in the San Juan and Gulf islands (Salo 1975). Eighty to 100
pairs were estimated to nest on the coastal islets of the Washington Islands
National Wildlife Refuge, 80 pairs in the San Juan Islands, and approximately
90 pairs in the Gulf Islands. Ninety-two to 100 breeding pairs were estimated
for the outer coast and 25 to 34 for the San Juan Islands and the Strait of
Juan de Fuca in Manuwal's (1977) survey. Principal nesting locations included
Long, Protection, and Smith islands.
Marine gastropods and bivalves, e.g., limpets, mussels, and chitons, of
rocky littoral habitats constitute the common prey of black oystercatchers
(Jewett, et al., 1953). Webster (1941) estimated that their diet in south-
eastern Alaska was composed of 30% ribbed limpets, Collisella digitalis; 20%
blue mussels (Mytilus edulis; 15% California mussels, M. californianus; 15%
gooseneck barnacles, Pollicipes polymerus; 13% shield limpets, Notoacmea
scutum; 5% black chitons, Katharina tunicata; 1% duncecap limpets, Acmaea
mitra; and polychaete annelids, Nereis sp. Hartwick (1973) indicated that
while mussels formed the greatest part by weight of the oystercatcher's diet,
crabs were of importance when chicks were present.
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Semipalmated Plover
Salo (1975) considered the semipalmated plover a common migrant in
western Washington, frequenting sandy beaches and tideflats during spring
(April-May) and fall (September-October). Large flocks of up to 1,000 birds
have been reported along the eastern end of the Strait of Juan de Fuca and in
the San Juan Islands during these periods. Wintering birds, however, may be
uncommon. Heilbrum, et al. (1977), reported only two birds during the 1976
Audubon Christmas bird count in the San Juan Islands and the Strait of Juan
de Fuca. Bent (1929) listed littoral invertebrates (molluscs such as
Littorina sp. and Mytilus sp. and crustaceans such as Gammarus sp., Limnoria
sp., and Orchestria sp.) and insects as the principal food organisms of
semipalmated plovers.
Whimbrel
Whimbrels apparently are common only during their fall (August) and
spring (May) migration periods, when 100 to 170 birds have been counted in
the Washington Islands National Wildlife Refuge and the San Juan Islands
(Salo 1975). Bent (1929) and Jewett, et al. (1953), described the diet of
wintering whimbrels as including polychaete annelids, molluscs, and
crustaceans.
Spotted Sandpiper
Although some spotted sandpipers winter in Washington, most are summer
residents which breed in the region (Jewett, et al., 1953; Alcorn 1971; Salo
1975). When present in marine habitats, principally sand and gravel beaches
and mudflats, spotted sandpipers eat mostly benthic invertebrates, including
polychaete annelids, gammarid amphipods, and molluscs.
Wandering Tattler
Jewett, et al. (1953), and Salo (1975) consider the wandering tattlers
as locally common migrants, most often observed in rocky shoreline habitats
of the exposed coast, the Strait of Juan de Fuca, and the San Juan Islands.
Their diet according to Bent (1929) includes small molluscs, crustaceans,
polychaetes, and insects.
Short-Billed Dowitcher
Although migrants to Washington, short-billed dowitchers are commonly
observed along the coast and through the Strait of Juan de Fuca to the San
Juan Islands. The peak spring migration is in April and May and the peak of
the fall migration is in September and October (Larrison and Sonnenberg 1968;
Salo 1975). They feed in small flocks of 10 to 50 birds in sand and mudflat
habitats, extracting marine annelids, flatworms, small molluscs, fish eggs,
and occasional plant matter from the shallow waters (Salo 1975).
Sperry's (1940) analysis of the stomach contents of 191 short-billed
dowitchers, collected mostly from the Atlantic coast of the United States
indicated that insects (29.1%, including 18% dipteran larvae, primarily '
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Stratiomyiidae, Empldidae, and Tabanidae, and 8.9% Coleoptera, including
aquatic Hydrophilidae and Dytiscidae), marine annelids (27.4%, including
Nereis sp.), and marine molluscs (20.9%, including Melampus sp. and
nassariid snails among the gastropods; and Gemma gemma, Ostrea virginica,
Mytilus edulis, and Venus mercenaria among the bivalves) were the principal
components of their diet. Crustaceans, including crabs (Uca sp.), shrimp
(Crago sp.), isopods (Cynthura carinata). ostracods, and amphipods, and
horseshoe crab (Limulus polyphemus) eggs were also found to a lesser degree
in the stomach contents of short-billed dowitchers.
Long-Billed Dowitcher
Although considered less common than short-billed dowitchers, migrant
long-billed dowitchers have been observed in great numbers in the coastal
embayments of Washington and are assumed to occur frequently in the San Juan
Islands (Salo 1975). Small flocks may overwinter in the region, as evidenced
by the 1976 Audubon Christmas bird count (Heilbrum, et al., 1977) which
included 17 individuals observed at Victoria, B.C.
Jewett, et al. (1953), and Salo (1975) assumed that long-billed
dowitchers feed upon coastal marine invertebrates—e.g., annelids, small
crustaceans, and molluscs—and some plant matter. The majority of the 107
stomach samples examined by Sperry (1940) were collected in inland areas,
but marine annelids (Nereis sp.), crustaceans (amphipods, including Echino-
gammarus ochotensis and Corophium spinicorne, and the isopod Exosphaeroma
oregonensis), and molluscs (gastropods, including Littorina sitchana) were
included as prey items. Smith and Mudd (1976) collected only a few specimens
in Grays Harbor. Examination of the esophagus of one specimen indicated
amphipods (Corophium sp.) and polychaetes were important prey but further
examination of the gizzard (which biases toward hard-food organisms) suggested
that clams (Macoma inconspicua and Mya arenaria) were also important.
Surfbird
Surfbirds migrate into western Washington in August and reside on rocky
shores and gravel beaches until April (Jewett, et al., 1953; Salo 1975).
They are most common along the exposed coast and rarer around Puget Sound.
The 1976 Audubon Christmas bird count (Heilbrum, et al., 1977) in this region
recorded surfbirds in abundance only at Nanaimo, B.C. Crustaceans and small
molluscs of the rocky littoral zones are the prey of surfbirds (Bent 1929).
Ruddy Turnstone
Ruddy turnstones, though fairly common migrants along the exposed coast,
are uncommon inside the Strait of Juan de Fuca and rarely over-winter in this
region (Salo 1975). Their diet resembles that of the sandpipers, i.e.,
polychaetes, molluscs, and crustaceans of beaches and mudflats (Bent 1929;
Jewett, et al., 1953; Salo 1975).
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Black Turnstone
Black turnstone is much more common than its congener ruddy turnstone
and is locally abundant in northern Puget Sound and the Strait of Juan de
Fuca as a migrant and winter resident (Jewett, et al., 1953; Salo 1975).
Heilbrum's, et al. (1977), account of the 1976 Audubon Christmas bird count
listed black turnstones at almost all stations in this region, but the
highest counts were at Victoria (212) and Vancouver (147), B.C. Molluscs
(limpets), barnacles, and other crustaceans common to the rocky littoral zone
are the basic prey items of black turnstones (Bent 1929; Jewett, et al.,
1953).
Greater Yellowlegs
Migrating greater yellowlegs occur in the region in April-May and July-
August, and are most common in northern Puget Sound (Jewett, et al., 1953;
Salo 1975; Heilbrum, et al., 1977). The highest count of overwintering birds
during the 1976 Audubon Christmas bird count was 34 at Victoria, B.C. Jewett,
et al. (1953), described their food as including molluscs, crustaceans, and
small fish.
Rock Sandpiper
Larrison and Sonnenberg (1968) described rock sandpipers as uncommon to
rare spring and fall migrants, although there may be some casual winter
residency (Alcorn 1971). Although little is known of their diet, small
crustaceans, molluscs, and insects are assumed to be important (Eaton 1975).
Dunlin
Dunlins are often one of the most common shorebirds encountered on the
coast of Washington, especially on the region's extensive mudflat habitat.
Dunlin dominated the shorebirds (almost 2,800 birds counted) at Dungeness
Spit during the 1977 Audubon Christmas bird count (1977 Olympic Pen. Audubon
Soc. Christmas Count Newsletter, unpub.).
Couch (1966) reported that wintering dunlins in northern Puget Sound
consumed mostly amphipods, especially Anisogammarus confervicolus at low tide
and Orchestoidea pugettensis at high tide. Benthic invertebrates, mainly
amphipods (69.7% of total number of identifiable prey, including Corophium
sp., 52.5%; Anisogammarus confervicolus, 16.5%; and Amphitoe sp., 0.7%),
polychaete annelids (8.5% of identifiable prey, including Nereis sp.,
Streblospio benedicti, Amphicteis mucronata, and Eteone longa), oligochaete
annelids (3.2%), molluscs (1.9%, including Macoma inconspicua and Mya
arenaria), tanaids (0.7%, Pancolus californiensis), and unidentified
nematodes (1.5%), were the principal prey of dunlins wintering in Grays
Harbor (Smith and Mudd 1976). It was also determined that during high tide,
dunlins supplemented the invertebrate-based diet with seeds of the saltmarsh
plants Spergularia marina and Triglochia maritinum. Few differences were
noted in diet composition among five sampling sites.
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Recher's (1966) analysis of the contents of 46 stomachs of dunlin
collected in California documented the nereid polychaete Nereis diversicolor
as the principal prey (70% frequency of occurrence), followed by ostracods
and amphipods. Studies by Bengtson and Svensson (1968) in southern Sweden,
and Ehlert (1964, cited in Kawaji and Shiraishi 1979) in the Baltic Sea
(Helgoland) illustrated generally the same preference for Itf. diversicolor.
The data provided by Madon (1935, cited in Wolf 1969) indicated that in
addition to ^J. diversicolor, molluscs, crustaceans, insects, and vegetable
matter were also important in the stomachs of dunlin along the Atlantic
coast of France. The Wild Bird Society of Japan (1975, cited in Kawaji and
Shiraishi 1979) and Kawaji and Shiraishi (1979) found that the polychaete
annelid Neanthes japonica; the gastropod molluscs Fluviocingula nipponica,
Salinator takii, and Ellobium chinense; and the bivalve mollusc Musculus
senhousia supplied the principal food items in nearshore regions of Japan.
Davidson (1971) showed a similar diet composition for dunlin collected in
Morecambe Bay, Lancashire, England.
The only deviation from the above documentation of benthic polychaetes
and molluscs as principal prey was that of Holmes's (1966) description of
dunlin food habits during its breeding season in arctic Alaska, when it
utilized larval and adult dipteran insects.
Knot
Both the American knot (Calidris canutus rufus) and the Pacific knot
(C.c^ rogersi) are found in Puget Sound infrequently (Alcorn 1971; Jewett,
et al., 1953; Salo 1975). When observed they are often in large flocks on
tidal flats and along the sand beaches of exposed coasts. The stomachs of
219 American knots collected from the east coast of the United States (Sperry
1940) contained, by volume, 59% molluscs (mainly Nassariidae, Littorina sp.,
and Melampus sp. among the univalves, and Donax sp., Gemma gemma, Mytilus
edulis, and Modiolus demissus among the bivalves); 14.8% insects (including
12.7% Diptera, i.e., Stratiomyiidae, Ephydridae, Tabanidae, Empididae, and
Tipulidae; 1.2% Coleoptera, i.e., Hydrophilidae; and 0.9% other insects, i.e.,
Formicidae, Pentatomidae, and Cydnidae); 8.9% crustaceans (including crab
eggs); 2.2% fish, marine annelids, and other incidental animals; and 15.2%
plants (primarily seeds of widgeongrass and other estuarine plants).
Least Sandpiper
Least sandpipers, common migrants and occasional winter residents in
this region, are quite abundant along the outer coast but also occur
frequently at Dungeness Spit and in the San Juan Islands (Jewett, et al.,
1953; Alcorn 1971; Salo 1975). April and May mark the spring migration,
August-September, the fall migration. Winter residents may be uncommon in
northern Puget Sound as few were reported during the 1976 Audubon Christmas
bird count (Heilbrum, et al., 1977). The principal food of least sandpipers
feeding on beaches and mudflats is the amphipod Anisogammarus confervicolus
(Couch 1966). Sanger (1970) indicated that elevated mudflats were preferred
foraging areas at high tide, whereas sandier mudflats were utilized during
low tide.
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Western Sandpiper
Western sandpipers are common spring and fall migrants in north Puget
Sound, occurring in April and May and again in July through December. Small
flocks are especially common in the San Juans and at Dungeness Spit (Jewett,
et al., 1953; Alcorn 1971; Salo 1975; Heilbrum, et al., 1977).
Smith and Mudd (1976) listed a wide variety of prey items of western
sandpipers wintering in Grays Harbor. Polychaete annelids (24.4%, including
Streblospio benedicti and other unidentified spionids and Eteone longa),
nematodes (13.3%), amphipods (8.9%, Euhaustorius washingtonius), adult and
larval insects (6.7%), and tanaids (2.2%, Pancolus californiensis) composed
the animal prey items, whereas saltmarsh plant seeds (40%, primarily Spergu-
laria marina but also including Triglochia maritimum and Deschampsia
cespitosa) were the main diet when the birds fed at high tide. Western
sandpipers collected from the San Juan Islands and other Pacific Northwest
sites had eaten mostly amphipods, including Anisogammarus confervicolus and
Corophium sp. (Couch 1966).
Sanderling
Sanderlings are common migrants and winter residents which form large
(e.g., 5,000 birds) flocks on the outer coast but smaller (e.g., 50) flocks
in north Puget Sound (Jewett, et al., 1953; Alcorn 1971; Salo 1975). They
were especially numerous at Bellingham and Dungeness Spit during the 1976
Audubon Christmas bird count (Heilbrum, et al., 1977). Amphipods (Anisogam-
marus confervicolus, Orchestoidea pugettensis) and bivalve molluscs (razor
clams on the outer coast) are their usual prey organisms (Cough 1966).
Wilson's Phalarope
Wilson's phalarope is a casual summer migrant and resident which
migrates to the area in May and leaves in August (Jewett, et al., 1953;
Alcorn 1971; Salo 1975). Jewett, et al. (1953), listed insects and their
larvae as the major food of sanderlings, although small crustaceans and
plants may also be consumed (Bent 1927).
Northern Phalarope
A much more common migrant than Wilson's phalarope, the northern phala-
rope occurs in high numbers (10,000-17,000 birds) in northern Puget Sound
in May and August as well as offshore (Jewett, et al., 1953; Salo 1975).
While insects appear to form much of the diet (80%), small crustaceans (9%),
polychaete annelids, small molluscs and fish, and plant material also
occurred in their diet (Bent 1927).
Parasitic Jaeger
Parasitic jaegers occur in Washington's marine habitats frequently
during their spring (April-May) and fall (July-December) migration through
the region (Jewett, et al., 1953; Alcorn 1971; Salo 1975). Since they
commonly obtain food by harassing gulls and terns into dropping or disgorging
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their food, parasitic jaegers are ultimately linked to the food resources of
gulls and terns (Salo 1975).
Pomarine Jaeger
Little information is available on the distribution or relative
abundance of pomarine jaegers in the region. Guiget (1971a) states that they
appear offshore of Vancouver Island, B.C. in small numbers in mid-July
increasing through September; occurrence in inland waters is apparently
scarce. Although they capture small birds and rodents, when in marine
environments they appear to gain most of their food by robbing gulls, terns,
and other marine birds.
Glaucous-Winged Gull
Glaucous-winged gulls have been described as the most commonly observed
gull in nearshore areas along the Washington coast (Sanger 1965) but are
encountered in abundance offshore only during November and January (Sanger
1970). Manuwal's (1977) survey of the breeding seabirds in Washington State
included an estimate of 6,234 breeding pairs in the San Juan Islands and the
Strait of Juan de Fuca; the largest populations included colonies on Colville
and Protection islands. They were the most prominent gull species surveyed
at Dungeness Spit in December 1977, totaling almost 600 birds (Olympic Pen.
Audubon Soc. 1977 Christmas Count Newsletter, unpub.).
Outram (1958) listed glaucous-winged gulls as one of the major causes
of herring egg mortality; the stomachs of 12 gulls that he examined contained
an average of 13,800 eggs. Fish, primarily capelin (Mallotus villosus)
occurred in the stomachs of 33% of the glaucous-winged gulls collected in
Alaskan waters by Sanger and Biard (1977). Pollock averaging 20 cm in length
were found in the stomachs of gulls associated with the Bering Sea pack ice
in April (Divoky, et al., 1977). James-Veitch and Booth (1954) listed chitons,
sea cucumbers, sea urchins, crabs (Cancer sp., Hemigrapsus sp.), blue mussels,
and polychaete worms (Nereis sp.) as prey of foraging glaucous-winged gulls.
Western Gull
Western gulls are the most common residents of Washington's outer
beaches and non-breeding gulls are common through the Strait of Juan de Fuca
and northern Puget Sound (Jewett, et al., 1953; Alcorn 1971; Salo 1975).
Hunt and Hunt (1976) examined the food items of western gull chicks on Santa
Barbara Island, California. They found that 89% of the food was composed
mostly of schooling fishes, and included northern anchovy (45% frequency
occurrence), jack mackerel (Trachurus symmetricus, 5.2%), Pacific saury
(Cololabis saira, 2.8%), midshipman (Porichthys sp., 1.9%), and squid.
Herring Gull
The common, ubiquitous herring gull occurs in every habitat of northern
Puget Sound and the Strait of Juan de Fuca and is especially well adapted to
urban coastal areas (Jewett, et al., 1953; Salo 1975). Verbeek (1977)
established that in the Cumbria, England, area, immature herring gulls relied
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more on stealing than on foraging, until they developed feeding skills,
whereupon starfish became the principal food item. Herring gull predation
upon spawned herring eggs in British Columbia was reported by Outram (1958),
who documented an average of 8,500 eggs per stomach for the nine stomachs
examined.
California Gull
California gulls occur in western Washington in abundance during their
fall and spring migrations and small numbers overwinter in Puget Sound
(Jewett, et al., 1953; Alcorn 1971; Salo 1975). Though observed frequently,
they were not very abundant during the 1976 Audubon Christmas bird count
(Heilbrum, et al., 1977). As many as 1,000 have been recorded at Dungeness
Spit in August (Salo 1975). Though the California gull apparently is as
omnivorous as the other gulls (Jewett, et al., 1953; Salo 1975), it also
preys specifically on juvenile sea or shore birds (Chura 1962).
Ring-Billed Gull
Ring-billed gulls are common winter residents in western Washington and
non-breeding birds may be found throughout the summer (Alcorn 1971; Salo
1975; Eaton 1975). Like the other large gulls, ring-billed gulls consume
almost anything available and edible, including small fish, refuse, insects,
and small rodents and birds (Guiguet 1971a; Salo 1975; Eaton 1975).
Mew Gull
Mew gulls are common winter residents along the Pacific Northwest coast
from October to April. Despite its common occurrence in this region, few
data on its food habits exist. In Alaskan waters they feed mainly on
unidentified crustaceans (83% frequency occurrence) and much less on fishes
(17%) (Sanger and Baird 1977), but are documented as feeding primarily on
small fishes when wintering in north Euget Sound and the Strait of Juan de
Fuca (Guiguet 1971a).
Heermann's Gull
As a common summer migrant, Heermann's gulls are most abundant in Puget
Sound from August to October (Alcorn 1971; Guiguet 1971a; Salo 1975). School-
ing neritic fishes, such as Pacific herring, or those of kelp beds are the
most common food organisms of Heermann's gulls, but they are also known to
parasitize Bonaparte's gulls and cormorants (Guiguet 1971a; Salo 1975).
Bonaparte's Gull
Bonaparte's gull occurs in Washington's marine waters primarily as a
migrant and winter resident, reaching peak abundance in October (Salo 1975).
Counts in the San Juan Islands National Wildlife Refuge included approximately
7,000 in April and up to 15,000 in August. Wahl (1977) reported that after
high abundances in October and November, only a few hundred were seen at
Active Pass, B.C., until April and May when the northward-migrating eulls
passed through.
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Little detailed information exists on the diet of Bonaparte's gull.
Jewett, et al. (1953). recorded that at times insects form the majority of
its prey. Salo (1975) suggested that "small fish and other marine life"
generally composed the diet. Guiguet (1971a) reported that small Pacific
herring and Pacific sand lance, forced to the surface by feeding salmon,
were fed upon by Bonaparte's gulls.
Sabine's Gull
Sanger (1965) reported one or two Sabine's gulls within five miles of
the Washington and Oregon coast during September and October, but it is
doubtful that they frequent the inshore waters of the Strait of Juan de Fuca
or northern Puget Sound (D. Manuwal, pers. comm.). Guiguet (1971a) reported
that Sabine's gulls feed upon crustaceans, small fishes, and marine annelid
worms.
Black-Legged Kittiwake
Kittiwakes winter well offshore the coasts of Washington and British
Columbia but may occasionally be encountered inshore, especially during
storm periods (Gabrielson and Jewett 1940; Jewett, et al., 1953; Sanger 1970).
Sanger and Baird (1977) examined the stomachs of 21 of 76 specimens collected
in Alaskan waters between 1969 and 1976. Fish (Pacific sand lance, 43%
freq. occur., and Pacific herring, 14%) occurred in 76% of these stomachs,
crustaceans (the hyperiid amphipod Parathemisto libellula, 29%, and the
euphausiid Thysanoessa raschi, 14%) in 19%, and squid in 5%.
Both fish and invertebrates entered the diet of black-legged kittiwakes
collected in the Cape Thompson vicinity of Alaska (Springer and Roseneau
1977). Fishes included polar cod (Boreogadus saida, 33% freq. occur.),
saffron cod (Eleginus gracilis, 33%), flatfish (7%), and ninespine stickle-
back (Pungitius pungitius, 7%); and invertebrates included gastropods
(Trochidae, 13%), crabs (13%), nereid polychaetes (7%), shrimp (Pandalus
goniurus, P_. montagui, Pandalus sp., and Eualus gaimardi, 7% each), isopods
(Saduria entomon, 7%), and insects (7%).
Fish (principally cod and capelin) and euphausiids (Thysanoessa inermis,
T_. longipes, T_. raschi, and T_. spinifera) were the main prey items of kitti-
wakes collected in the Pribilof Islands (Hunt 1977). Birds feeding along the
southern edge of the Bering Sea icepack in March and April had consumed
capelin and walleye pollock (Theragra chalcogramma) (Divoky, et al., 1977).
The diet of black-legged kittiwakes of the Fame Islands in Great Britain
was almost completely composed of fish (98% prey abundance, 99% biomass),
primarily sand lance (Ammodytidae), herring (Clupeidae), and cod (Gadidae).
Common Tern
Whereas common terns migrate rapidly along the Pacific coast in the
spring, the fall migration during August to October brings them to the coastal
and Strait of Juan de Fuca areas (Jewett, et al., 1953; Alcorn 1971; Salo
1975). Salo (1975) reported 250 common terns observed at Dungeness Spit in
August. Common terns feed mainly on small neritic fishes (Salo 1975) which
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in this region would include Pacific herring, Pacific sand lance, smelt
(Osmeridae), and juvenile salmon.
Arctic Tern
Arctic terns are common migrants along the Pacific Northwest coast and
in north Puget Sound (Guiguet 1971a). A small breeding colony (7-12 pairs)
has been reported to occur on Jetty Island near Everett, Washington
(D. Manuwal, pers. comm.). Crustaceans (unidentified) occurred in 100% of
the stomachs of birds collected by Sanger and Baird (1977) from Alaskan
waters between 1969 and 1976. Pacific sand lance and herring composed the
majority of the prey abundance (87%) and biomass (85%) of arctic terns in the
Fame Islands of Great Britain (Pearson 1968).
Caspian Tern
Although at the approximate northern extremity of their West Coast
distribution, Caspian terns are common, both as fall migrants and as breeding
birds (approximately 2,500), on the outer Washington coast (Robbins, et al.,
1966; Eaton 1975). Smith and Mudd (1976) reported the species composition
of 31 fish removed from a Grays Harbor ternery. Shiner perch composed over
half of the fish collected; juvenile chum salmon (Oncorhynchus keta) and
Pacific staghorn sculpin were also common; white seaperch (Phanerodon furca-
tus). whitebait smelt (Allosmerus elongatus), snake prickleback, cutthroat
trout, and longnose dace (Rhinichthys cataractae) were also found. Bent
(1921) also suggested shrimp, mussels, and eggs and young of other birds as
prey items.
Common Murre
Common murres breed in large concentrations in crevices or on steep
cliffs, on the large stacks and islands of the outer coast, especially around
LaPush, Washington (Cody 1973), and are very abundant in the Strait of Juan
de Fuca from August through October. Manuwal (1977) documented 11,950 pairs
of common murres nesting on the outer coast of Washington. The largest
breeding populations were located in the Point Grenville and Willoughby Rock
vicinities.
The best documentation of common murre prey spectrum is in Scott's
(1973) study at Yaquina Head, Oregon. His results substantiated earlier
reports by Belopol'skii (1957) and Bedard (1969) that common murres feed
mainly on midwater fishes. Scott's study indicated that eulachon (Thaleich-
thys pacificus) and northern anchovy were the most important prey of the
regon. Juvenile rockfish became a major constituent of the diet of fledg-
lings after they had left the breeding rocks. In one year, however,
epibenthic crustaceans (euphausiids, mysids) constituted 86.2% of the total
prey volume, a result that Scott attributed to the lack of midwater schooling
fishes in the area at that time. Using Scott's data, Wiens and Scott (1975)
calculated the total animal energy demand of common murres off Oregon to be
3.488 k cal nr2, the highest of the four species they examined.
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Steele and Drury (1977), Hunt (1977), and Sanger, et al. (1977), also
documented the importance of midwater fishes in the prey spectrum of common
murres in Alaskan waters. The principal prey species were capelin, Pacific
sand lance, walleye pollock, a prickleback (Lumpenus fabrici), and several
other unidentified cod and smelt. Fish, primarily Pacific sand lance,
occurred in 77% of the stomachs examined from Alaskan waters by Sanger and
Baird (1977); crustaceans (unidentified) occurred in only 15%.
Common murres in the Cape Thompson vicinity of Alaska appeared to
utilize primarily polar cod (42% freq. occur.), saffron cod (33%), Pacific
sand lance (17%), and unidentified sculpins (17%) (Springer and Roseneau
1977). Murres collected over the Bering Sea pack ice in March by Divoky,
et al. (1977), had consumed 7.5-18 cm long pollock and 10-14 cm long capelin,
but the hyperiid amphipod Parathemisto sp. occurred the most frequently in
the stomach, though providing less than one percent of the total prey
volume; euphausiids appeared more often (57% freq. occur., 20.4% volume) in
April.
Tuck's (1960) summary analysis of the diet of North Atlantic murres
also confirmed that they eat midwater schooling fishes, specifically gadids
(cod and haddock), sand lance, herring, and capelin, but also included such
diverse benthic fishes as sculpin and flatfish. Although they were not a
significant proportion of the total prey volume, a variety of invertebrates
(shrimp and cephalopod molluscs) also occurred in the diet. Common murres
in the Pembrokeshire region of Great Britain were observed to feed their
chicks sand lance and small herring (Clupea sprattus) in the 50-175 mm size
range (Harris 1970).
Pigeon Guillemot
Pigeon guillemot is ubiquitous throughout the region, breeding in small
colonies on high cliffs both offshore and inshore (Cody 1973). Manuwal (1977)
estimated 161 breeding pairs along the outer Washington coast and 194 pairs
in the San Juan Islands and the Strait of Juan de Fuca; prominent colonies
in the latter region include Castle, Protection, Skipjack, and Smith islands.
They were tenth in total abundance of the diving birds observed during the
San Juan Island ferry transect surveys.
In Cody's (1973) ecological analysis of Washington's alcid communities,
the pigeon guillemot's diet is distinguished from the other alcids1 diets by
its dependence on shallow sublittoral fishes, specifically "blennies"
(Pholidae and Stichaeidae?), and clingfish (Gobiesocidae). Cody's analysis
was supportive of earlier, more general reports, including Drent (1965) who
reported that over 70% of the diet of pigeon guillemot on Mandarte Island,
B.C., was composed of blennies, flatfish, and sculpins, and Thoresen and
Booth (1958), who listed Pacific sand lance, surf smelt (Hypomesus pretiosus),
black prickleback (Xiphister atropurpureus), snake prickleback, and small
flatfish as the principal prey fed to nestlings. Fourteen of 16 prey items
consumed by pigeon guillemots in Yaquina Bay, Oregon, were flatfish; the
other two were blennies (Scott 1973). The same study also mentioned one
flatfish, eight planktonic crustaceans, and two crabs as the prey found in
two adults collected offshore. Both fish and crustaceans (euphausiids,
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Thysanoessa inermis) were represented in the stomachs of pigeon guillemots
collected in Alaskan waters between 1969 and 1976 by Sanger and Baird (1977).
Tufted Puffin
The only puffin which occurs in north Puget Sound and the Strait of Juan
de Fuca and which plays any significant role in the food web is the tufted
puffin (Lunda cirrhata). It is particularly abundant along Washington's
northwest coast where it nests in colonies on the larger stacks and islands
such as Carroll Island, Alexander Island, and Cake Rock (Cody 1973). One
population estimate for the outer coast region was 7,343 nesting pairs
(Manuwal 1977). Tufted puffin do not, however, nest in abundance inside the
Strait of Juan de Fuca, as Protection Island which has the largest breeding
colony in the region has only 25 to 30 nesting pairs (Manuwal 1977).
Cody's (1973) comparative study of the alcids indicated that primary
prey delivered to nestlings by adult birds were, in decreasing order of
importance, Pacific sand lance, northern anchovy, rockfish, and smelt.
Sealy (1973) also listed Pacific sand lance as the major prey in June
delivered by nesting adults. Manuwal (1977), however, did not identify
Pacific sand lance as an important prey, rather smelt (Hypomesus?), Pacific
herring, and northern anchovy. Manuwal (1977) and Bent (1929) also suggested
that feeding adults have a broader prey spectrum that includes crustaceans,
mussels, sea urchins, surf smelt, Pacific sardine (Sardinops sagax), Pacific
herring, seaperch (Embiotocidae), Pacific sand lance, northern anchovy, and
rockfish.
Amaral (1977) and Manuwal and Boersma (1977) reported 94.5% of the prey
delivered (89.5% freq. occur.) to tufted puffin chicks on the Barren Islands,
Alaska, was capelin; prowfish (Zaprora silensus) and squid also occurred but
were insignificant. Sanger and Baird (1977), however, noted that fish and
squid occurred approximately equally in their collections of tufted puffin
in Alaskan waters between 1969 and 1976; Pacific sand lance was the only
fish species identified from the stomach contents. Sanger, et al. (1977),
listed capelin, Pacific sand lance, walleye pollock, and invertebrates as
the principal prey of tufted puffin in the Kodiak Island area. Cod and
capelin composed all of the prey of tufted puffin sampled by Hunt (1977) on
St. Paul Island in the Pribilofs in 1976, but a year earlier the diet had
been volumetrically dominated by unidentified crabs.
Rhinoceros Auklet
More than 11,000 breeding pairs of rhinocerus auklets were estimated
along the outer coast, principally at Destruction Island, while 9,800 pairs
were estimated for the San Juan Island and Strait of Juan de Fuca region,
these breeding mainly at Protection Island (9,200) and Smith Island (600)
(Manuwal 1977). As one of the most abundant seabirds occurring in the Strait
of Juan de Fuca and the outer northwest Washington coast, rhinoceros auklets
of this region have been studied extensively over the past few years,
especially their diet (Richardson 1961; Cody 1973; Leschner 1976; Manuwal
iy//; Wilson 1977). In most cases, these data were collected for breeding
f°°d f°r nestlin8s' mainly on Destruction and Protection
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Richardson's (1961) documentation of prey delivered to nestlings on
Protection Island listed 4-6 inch long Pacific sand lance as the main prey
item, the only other fish being a surf smelt. The bill loads averaged 6.4
Pacific sand lance (ranging from 1 to 13 fish) and included extremely fresh
fish, suggesting feeding grounds within 10 miles of Protection Island.
Annual variation was most obvious in the data obtained by Leschner
(1976) from Destruction Island. Northern anchovy accounted for 56.0%,
Pacific herring, 20.8%, and surf smelt, 15.3%, of the prey delivered to
nestlings in 1974. In 1975, night smelt (Spirinchus starksi) and Pacific
sand lance predominated (31.9% and 31.7%, respectively), followed by northern
anchovy (26.8%). Species composition also varied considerably over the
nesting period.
The comprehensive study by Wilson (1977) indicated that Pacific sand
lance and Pacific herring were the most important prey of rhinoceros auklets
nesting on Protection Island in 1975 and 1976, composing 90.6% of the total
weight of 1,198 prey items over that time. Juveniles of all four species of
Pacific salmon, adult northern anchovy and surf smelt, juvenile walleye
pollock, and threespine stickleback occurred to a lesser extent. Prey
species composition reported by Wilson varied less during the nesting period
between 29 June and 29 August 1976 than the prey composition reported by
Leschner (1976). In Wilson's study, juvenile salmonids declined slightly
and Pacific herring increased slightly over that period. Peak utilization
of Pacific sand lance occurred at the end of July, coinciding with the peak
abundance of chicks being fed on the island. Wilson also documented an
average daily consumption rate for nestling rhinoceros auklets of 54-55 g
Pacific herring per day.
Manuwal's (1977) studies provide the most extensive data on rhinoceros
auklet prey items and quantities. Although there was some annual variation
between the two years sampled, prey delivered to nestlings on Protection
Island were mostly Pacific sand lance and herring in terms of both numbers
and biomass, augmented by juvenile salmon and several other neritic fishes
(Table C-3). This prey spectrum was quite dissimilar to the spectrum at
Destruction Island on the outer coast, where northern anchovy and night smelt
were more important, and where annual variation in prey composition was more
pronounced. Prey composition based on weight also shifted slightly over the
nesting period (nine weeks) at Protection Island. Juvenile salmon were more
important in the first four weeks, whereas Pacific herring gradually
increased in importance through the nesting period. The average number of
fish delivered to chicks on Protection Island was similar during the two
years (5.62 in 1975, 5.65 in 1976) but the average weights of the loads were
not similar (32.28 g in 1975, 29.52 in 1976) and the patterns over time were
also dissimilar.
Outside the north Puget Sound and Strait of Juan de Fuca area,
euphausiids appeared to be more important in the diet of adult rhinoceros
auklets and their nestlings (Grinnel 1899; Linton 1908; Kozlova 1957; Komaki
1967). Pacific sand lance, however, dominated the stomach contents of four
rhinoceros auklets collected in Alaskan waters (Sanger and Baird 1977).
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Table C-3. Percent composition of numbers of prey delivered to rhinoceros
auklet nestlings on Protection Island (from Munuwal 1977).
1975
Prey
Pacific sand lance
Pacific herring
Chinook salmon, juv.
Pink salmon, juv.
Chum salmon, juv.
Coho salmon, juv.
Northern anchovy
Surf smelt
Walleye pollock
Threespine stickleback
Squid (unidentified)
% Number
82.78
14.44
0.56
0
1.11
0
0.56
0
0
0.56
0
% Weight
70.60
26.02
1.55
0
0.87
0
0.77
0
0
0.19
0
1976
% Number
74.36
20.53
1.08
2.26
0
0.10
0.79
0.39
0.39
0
0.10
% Weight
63.76
25.72
3.01
3.50
0
0.19
2.09
1.43
0.13
0
0.17
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Cassin's Auklet
Although common offshore, Cassin's auklets are not frequently
encountered nearshore, but they have been reported to breed on Carroll and
Alexander islands and on Cake Rock on the outer coast (Cody 1973). According
to Cody, Cassin's auklet is the only alcid in Washington that forages on
plankton at long distances. The plankton is regurgitated as a soup to the
nestlings. Thoreson (1964) and Manuwal (1974) documented euphausiids
(Thysanoessa spinifera), amphipods (Phromema sp.), and squid as the main
components of their diet off the coast of California. Sanger and Baird
(1977) listed only unidentified crustaceans in the stomach contents of five
Cassin's auklets collected in Alaskan waters.
Ancient Murrelet
Although neither Salo (1975) nor Manuwal (1977) includes ancient
murrelets in his survey, they appear, although infrequently, in the northern
reaches of Puget Sound during migration from their breeding sites in Alaska
and British Columbia and many may overwinter in the region (Sealy 1976).
The 1976 Audubon Christmas bird count recorded 377 at Victoria, B.C., and
incidental sightings at Pender Islands and Vancouver, B.C., and Bellingham,
Washington (Heilbrum, et al., 1977).
Sealy's (1972) detailed comparison of the feeding ecology of the marbled
murrelet and the ancient murrelet during the breeding season in the Queen
Charlotte Islands, B.C., illustrated that adult ancient murrelets prey
specifically on euphausiids (Euphausia pacifica, Thysanoessa spinifera),
which composed 92.4% of the total prey abundance, while fish (Pacific sand
lance and shiner perch) made up only 7.2%. Subadult birds, however, fed
more upon fish, primarily Pacific sand lance 30-60 mm in length, which
accounted for 45.7% of the total prey abundance vs. 55.3% for invertebrates.
Juvenile ancient murrelets were essentially piscivorous (98.3%). The
euphausiid IS. pacifica prevailed in the diet in March and April before it was
supplanted by T_. spinifera; Pacific sand lance and shiner perch occurred
during the period between mid-June and mid-July. Sealy (1973) also noted
that ancient murrelets often fed in conjunction with black-legged kittiwakes
and glaucous-winged gulls, which were feeding on similar prey organisms at
the surface. The results of Sanger and Baird's (1977) examination of ancient
murrelets in Alaskan waters were generally similar, the euphausiid Thysano-
essa inermis being the principal prey of adult birds.
Marbled Murrelet
Marbled murrelets are an abundant summer bird along the Pacific North-
west coast (Drent and Guiguet 1961) and are presumed to nest inland on large
rivers (Hoh and Quileute) of the Olympic Peninsula (Cody 1973).
Compared with the prey spectrum of adult ancient murrelets, that of
adult and subadult marbled murrelets is much more oriented toward fish.
Sealy (1972) documented that small (less than 60 mm in length) Pacific sand
lance provided 61.8% of the total prey abundance of prey organisms for
marbled murrelets in the Queen Charlotte Islands, B.C.; shiner perch,
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rockfish, osraerids (smelt, capelin, eulachon), and prickleback were other
important fishes. Euphausiids (Thysanoessa spinifera) larger than 12 mm
formed the majority of the invertebrates consumed, which overall contributed
only 26.8% of the total prey abundance, and occurred only early (mid-April to
late June) in the breeding season. Shiner perch and osmerids appeared in the
diet primarily in the latter half of the breeding season (early July to mid-
August). Sealy (1973) also found marbled murrelets feeding upon T\ spinifera
in conjunction with glaucous-winged gulls.
Manuwal and Boersma (1977) also listed fish (unidentified) as the main
constituent (67% abundance) of the food of marbled murrelets collected in
the Gulf of Alaska and the southeastern Bering Sea. Both fish (67% freq.
occur.) and unidentified crustaceans (33%) occurred in marbled murrelets
collected in Alaska' south-central waters (Sanger and Baird 1977).
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REFERENCES
Alcorn, G.D. 1971. Checklist, birds of the State of Washington. Occasional
Papers 41, Dept. Biol., Univ. Puget Sound. 59 pp.
Amaral, M.J. 1977. A comparative breeding biology of the tufted and horned
puffin in the Barren Islands, Alaska. M.S. Thesis, Univ. Washington,
Seattle.
Bakus, G.J. 1965. Avifauna of San Juan Island and archipelago, Washington.
Allan Hancock Foundation, Univ. Southern California, Los Angeles. 36 pp.
Bedard, J. 1969. Adaptable radiation in Alcidae. Ibis 3(2):189-198.
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258
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APPENDIX D. MARINE MAMMALS
D-l. Cetaceans
Scheffer and Slipp (1948) recorded 20 species of cetaceans (whales,
dolphins, and porpoises) in the marine waters of Washington State; Pike and
MacAskie (1968) listed 21 from British Columbia (Table Dl).* These
comprehensive accounts, however, were based principally upon records of
the coastal whaling stations** and of strandings, rather than upon
systematic survey observations with estimates of abundance. As a result
they do not necessarily reflect whale populations of today, many of which
(sperm and humpback whales) have been seriously depleted by overharvesting;
only gray whales have recovered to their estimated original abundance.
In addition, only a few of the cited species were ever common to the
enclosed waters of Puget Sound, the Strait of Georgia, and the inner Strait
of Juan de Fuca, though many were encountered during aboriginal whaling
activities by the Makah Indians, who were located on the western end of the
Strait of Juan de Fuca. Of the modern occurrences of cetaceans in the
region's inland waters, only two cetaceans—orca (killer whale) and harbor
porpoise—can still be considered abundant, and four—Pacific white-sided
dolphin, Ball porpoise, gray whale, and Minke whale—are still relatively
common. The following species accounts consider all cetaceans reported in or
adjacent to the Strait of Juan de Fuca and northern Puget Sound, but the
preceding food web section discusses only the six species which now occur in
the region.
All the cetaceans documented for the region have been categorized
according to six functional feeding groups (Table D-2). Of the common or
abundant species, gray and Minke whales were determined to be obligate
planktivores and the Pacific white-sided dolphin and the Ball porpoise,
facultative piscivores in pelagic habitats; in nearshore habitats, the Pacific
harbor porpoise has been classified as an obligate piscivore while the orca
or killer whale sits at the peak of the marine food web as a facultative
carnivore.
*Nomenclature has been standardized according to Rice (1977).
**Statistics came mostly from one station operating at Bay City,
Washington, from 1911 to 1925 and another at Coal Harbour on Vancouver Island,
British Columbia, from 1948 through 1959 and 1962 through 1967.
259
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Table D-l. Cetaceans occurring in Washington State and British Columbia. A = abundant, C = common,
NC = not common, R = rare, c = coastal only, i = inshore Puget Sound and Strait of
Juan de Fuca.
Washington State British Columbia
(Scheffer and (Pike and Reported
Order Cetacean—whales and dolphins Slipp 1948) MacAskie 1969) habitat
Suborder Odontoceti—toothed whales and dolphins
Family Ziphiidae—beaked whales
Berard-ius bai.vdi.-L Stejneger, Baird's beaked whale NC C i
Mesoplodon stejnegeri True,
Stejneger beaked whale R Re
M. oavlhubbsi Moore, Hubbs' beaked whale R c
Ziphius cavirostris Cuvier, Cuvier's beaked whale R i
Family Physeteridae—sperm whales
Physeter oatodon Linnaeus, sperm whale C C c
Kogia breviaeps Blainville, pygmy sperm whale NC i
Family Delphinidae—ocean dolphins
Stenella sp., spotted dolphin R i
Delphinus delphis Linnaeus, Pacific common dolphin R R i
Lissodelphis bmvalis Peale,
northern right-whale dolphin R Re
Lagenorhynchus obliguidens Gill,
Pacific white-sided dolphin C C i
Orcinus oroa Linnaeus, killer whale or orca A A i
Grampus gr-iseus Cuvier, gray grampus or
Risso's dolphin R i
Pseudorca OTassidens Owen, false killer whale R i
Globiccphala macvovh'ijnc'ha, shortfin pilot whale NC NC i
Thocoena phoaoena Linnaeus,
Pacific harbor porpoise A A i
Phojoenoides dalli True, Dall porpoise C C i
Family Monodontidae—Arctic dolphins
Delphinapterus leucas, beluga whale R c
-------
Table D-l. Cetaceans occurring in Washington State and British Columbia. A = abundant, C - common,
NC = not common, R = rare, c = coastal only, i = inshore Puget Sound and Strait ot
Juan de Fuca - cont'd
Order Cetacean—whales and dolphins
Washington State British Columbia
(Scheffer and (Pike and Reported
Slipp 1948) MacAskie 1969) habitat
NJ
Suborder Mysticeti—whalebone whales
Family Eschrichtiidae—gray whales
Eschrichtius robustus Lilljeborg, gray whale
Family Balaenopteridae—furrow-throated whales
Balaenoptera physalus Linnaeus, fin or finback whale
B. borealis Lesson, sei whale
B. acutovostrata Lacepede,
little piked whale, minke whale
B. muscutus Linnaeus, blue whale
Megapteva novaeangliae Borowski, humpback whale
Family Balenidae—smooth-throated whales
Balaena glacialis Muller, northern or
black right whale
C
C
NC
NC
R
C
C
NC
NC
NC
1
c
i
c
i
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Table D-2. Functional feeding groups and representative prey taxa of marine mammals known or suspected
to occur in north Puget Sound and the Strait of Juan de Fuca. Species common or abundant in
the region are underlined. Species involving questionable sightings or extremely rare
species are in parentheses.
Habitat
Feeding group
Predator species
Representative prey taxa
Pelagic
Obligate planktivore
ON
Facultative
(macro-)planktivore
Obligate piscivore
Gray whale*
Finback whale
Sei whale
Minke whale
Blue whale
North Pacific right
whale
Humpback whale
(Shortfin pilot whale?)
Gray grampus dolphin?
False killer whale
Northern fur seal
Northern elephant seal
(Beluga whale)
Calanoid copepods (Calanus sp.)
Euphausiids (Euphausia paeifioa, Thysano-
essa sp.)
Crab zoea (Pachyaheles Tudis, Cancer sp.)
Squid (Ommastrephes sp.)
Pacific saury (Coloabis saira)
Northern anchovy (Engraulis mordax)
Walleye pollock (Theragra chalcogTcama)
Pacific sand lance (Ammodytes hexaptevus)
Squid (Gonatidae, Histioteuthidae,
Ommastrephidae, Onychoteuthidae)
Rockfish (Sebastes sp.)
Lingcod (Ophiodon elongatus)
Skate (Rajiidae)
Lancetfish (Alepisaw?us sp.)
Shark (Squaliformes)
Surf smelt(Hypomesus pretiosus)
Atka mackerel (Pleurogrammus
monoptery gins')
Pacific sardine (Sardinops sagax)
Euphausiids (E. pacifica, Thysanoessa sp.)
Capelin (Mallotus villosus)
Pacific herring (Clupea harengus pallasi)
Pacific sardine (5. sagax*)
Salmon (Oncorhynchus sp.)
Northern anchovy (E. mordax)
Walleye pollock (T. ohalcograrma)
Eulachon (Thaleichthys pacifiGus)
Pacific sand lance (A. hexapterus)
-------
Table D-2, cont'd
Habitat
Feeding group
Predator species
Representative prey taxa
Facultative piscivore
Nearshore Obligate piscivore
Baird's beaked whale
Stejneger beaked whale
and other Mesoplodcni sp.
(Cuvier's beaked whale)
(Spotted dolphin,
Stenella sp.)
(Pacific common dolphin)
Pacific white-sided
dolphin
Northern right-whale
dolphin?
Pall porpoise
Pygmy sperm whale
Harbor porpoise
Northern sea lion
California sea lion
Pacific harbor seal
Squid (Loligo opalescens, Gonatus sp.,
Ormastrephes sp., Onyehoteuthis sp.)
Lanternfish (Myctophidae, Diaphus sp.)
Pacific hake (Merlucaius produotus)
Northern anchovy (E. mordax)
Pacific saury (C. saira)
Squid (Gonatus sp., Onychoteuthis sp.,
L. opalescens}
Shrimp (Bentheogennema borealis, Pasiphaea
pacifioa, Pandalus sp.)
Pacific herring (C. harengus pallasi)
Capelin (M. villosus)
Juv. rockfish (Sebastes sp.)
Salmon (Oncorhynchus sp.)
Octopus (Octopus so.)
Pacific herring (C. harengus pallasi)
Pacific sand lance 04. ~hexa.ptems)
Walleye pollock (T. chatcogramma)
Salmon (Oncorhyna'hus sp.)
Starry flounder (Platiehthys stetlatus)
Pacific tomcod (Miorogadus pacificus)
Rockfish (Sebastes sp.)
Skate (Rajiidae)
Pacific cod (Gadus maopocephalus)
Pacific hake (M. productus)
Spiny dogfish (Squalus aoanthias')
Plainfin midshipman (Porichthys notatus)
Greenling (Hexagrammidae)
Shiner perch (Cymatogaster aggregata)
-------
Table D-2, cont'd
Habitat Feeding group
Predator species
Representative prey taxa
Facultative carnivore Orca (killer whale)
S3
Pacific staghorn sculpin (Leptooottus
armatus)
Eelpout (Zoarcidae)
Blackfin sculpin (Malacocottus ki-ncaidi)
Shrimp
Crabs (Cancer sp.)
Octopus (Octopus sp.)
California sea lion (Zalophus
californianus)
Northern sea lion (Eumetopias jubatus)
Harbor seal (Phoca vitulina)
Elephant seal (Mirounga californianus)
Harbor porpoise (Phoeoena phocoena)
Ball porpoise (Phocoenoides dalli)
Minke whale (Balaenoptera acutorostrata)
Nursing calves of humpback (Megaptera
novaeangliae'), finback (Balaenoptera
physalus), and gray whales (Eschrichti-us
robustus)
Lingcod (0. elongatus)
Salmon (Oncorhynchus sp.)
Steelhead trout (Salmo gairdneri)
Pacific halibut (Hippoglossus stenolepis)
Pacific herring (C. harengus pallasi)!
*0n feeding grounds outside the north Puget Sound - Strait of Juan de Fuca region, gray whales feed
on benthic and epibenthic organisms.
?—denotes subjective assignment of predator species to feeding group in absence of food habits data.
-------
Species Accounts
Baird's Beaked Whale
Looking much like a small sperm whale (10-15 m long at maturity), Baird's
beaked whale appears to occur principally along the coast, peak occurrences
being in the fall. Six whales were reported in early October 1976, 75 km
offshore of Westport, Washington, by Wahl (1977). Of thirteen stomachs
examined from the Coal Harbour station between 1950 and 1958, three were
empty. Squid and rockfish (Sebastes spp.) bones appeared in seven stomachs
and skate egg cases were found in the stomach contents of two.
Stejneger Beaked Whale and Other Mesoplodon sp.
Another group of beaked whales includes three species of Mesoplodon,
of which M. stejnegeri appears to be the prominent species. They appear
typically along the coast, although an early record by Scammon (1874)
indicated a large number may have occurred in Port Townsend Bay (Scheffer and
Slipp 1948). There is no recorded account of stomach contents of any of these
species. We assume they would feed similarly to the other beaked whales, i.e.,
basically upon squid and fishes.
Cuvier's Beaked Whale
Although no confirmed records of Cuvier's beaked whale originate from
Washington, there have been a number of records from the west coast of Van-
cover Island and the Queen Charlotte Island area. Little stomach contents
information is presently available. Recently, a Cuvier's beaked whale, 4.3 m
in length, washed ashore on the north side of Nizki Island in the western
Aleutians, and the stomach was examined and reported to contain squid remains
(R.M. Mayer, Fish. Res. Inst., personal communication, 1979).
Sperm Whale
Although now seldom reported off the coast of Washington, the largest
of the toothed whales (15-20 m at maturity) were third in abundance in the
catch at Bay City, Washington, stations, 1913-1915 and 1918-1919 (Scheffer
and Slipp 1948), and composed almost 80% of the whales taken at Queen Charlotte
Islands' whaling stations between 1933 and 1943, and 32% of those taken at
Coal Harbour between 1948 and 1959 (Pike and MacAskie 1968). Sperm whales
therefore may have been a predominant species before coastal whaling off
Washington and southern British Columbia and present high seas whaling reduced
their numbers. They appeared from late spring through early fall in large
harem schools in the open ocean up to 200 miles from the west coast of British
Columbia (Pike and MacAskie 1968). This concentration was apparently a
feeding aggregation, as most stomachs contained food organisms, including
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squid (Moroteuthis robusta and Gonatus sp.), hagfish (Eptatretus stouti), and
rockfish. Octopi, codfish (Gadidae), and a lamprey (Petromyzontidae)
constituted incidental prey items (Robbins, et al., 1937).
Small to moderate sized cephalopod molluscs (squid and octopus) appeared
to be the prevalent prey items of sperm whales on most localities including
the western Gulf of Alaska (Thompson 1940; Kawakami 1976), the Bering Sea
(Okutani and Nemoto 1964), California (Fiscus and Rice 1974, Japan (Okutani,
et al., 1976), the Kurile Islands (Bethesheva and Akimushkin 1955), New
Zealand (Gaskin and Cawthorn 1967), Spain (Clarke and MacLeod 1974), and
Northwest Africa (Clarke 1962). Taxonomic composition of the squids varied
according to the geographic region, but the family Gonatidae composed more
than half of the squid prey reported for the North Pacific. Okutani, et al.
(1976), identified 15 species belonging to 9 families where species of the
families Histioteuthidae, Ommastrephidae, and Onychoteuthidae numerically
predominated. The so-called giant squid, Architeuthis sp. and Moroteuthis
robusta, did not occur frequently but contributed high biomass proportions
when they did occur.
Fish appeared less frequently than squid in almost all circumstances
but often contributed considerably to the total prey biomass. Gaskin and
Cawthorn (1967) documented a 1.7:1 ratio of squid to fish by weight. All of
the 14 sperm whale stomachs examined at Port Hobron in 1937 and 8 of the 13
from Akutan in 1938 had cephalopod remains. Fish (lingcod, Ophiodon
elongatus), rockfish, skates (family Rajiidae), and their egg cases) and
hermit crabs (Paguridae) were secondary prey items (Thompson 1940).
Backus (1966) described the contents of one sperm whale from the Azores
as containing "10 or 12 photophore-bearing cephalopods, each about 1 m in
total length, 2 lancetfish (Alepisaurus sp.), each about 1 m long, and the
partial remains of a large shark" (probably Cetorhinus maximus).
Spotted Dolphins
No specimen records nor stomach contents of spotted dolphins (Stenella
styx, S^. euphrosyne, and S^. caeruleoalba) have been examined from the
northern Washington or southeastern British Columbia coasts. Wahl (1977)
reported one sighting of J5. caeruleoalba, 72 km northwest of Westport in late
September 1976.
Miyazaki, et al. (1973), provided detailed stomach contents analyses of
27 specimens of S^. caeruleoalba from Sagami Bay, Japan. An average of 53.6
+ 43.6 (+ 1 s.d.) prey organisms comprising 7.6 + 3.5 species was contained
in each stomach, weighing an average of 1,074 + 418 g. Fish numerically
dominated the stomach contents at 59% of the total prey abundance. Lantern-
fishes were the prevalent group, especially Diaphus sp., accounting for 64%
of all identified fishes. The estimated body lengths of consumed fishes
ranged from 60 to 300 mm. Shrimp, especially Bentheogennema borealis, were
also common prey components, followed by squid. All prey species were pelagic
or epipelagic. Since the coastal environments of central Japan and northern
Washington and southern British Columbia are similar, the food habits of this
genus of dolphin may also be similar.
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Pacific Common Dolphin
One specimen of this species, relatively rare in the region, recovered
at Victoria, B.C., was not examined for stomach contents. Fiscus and Niggol
(1965) reported the stomach contents of four animals from central California.
Fish—Myctophidae, northern anchovy (Engraulis mordax), Pacific saury (Colo-
lab is saira)—and squid (Gonatus sp., Onychoteuthis sp., Loligo opalescens)
were the predominant prey items.
Northern Right-Whale Dolphin
One right whale found stranded on a southwestern Washington coastal
beach had one squid beak in its stomach (Scheffer and Slipp 1948). About 20
individuals were observed by Wahl (1977) in association with gray grampus
dolphins in October 1974, 85 km west of Westport.
Pacific White-Sided Dolphin
Pike and MacAskie (1969) listed 32 sightings of Pacific white-sided
dolphins from British Columbia and northern Washington which suggested an
inshore movement in winter and an offshore movement in summer. The northern-
most observation made by Fiscus and Niggol (1965) was off Point Grenville;
they reported few Pacific white-sided dolphins inside the 100-fm and few
outside the 1,000-fm curve. Wahl (1977) included one report of 25-30 Pacific
white-sided dolphins observed 72 km northwest of Westport in late September
1976. Extremely large pods of 1,000-2,000 animals have been reported in the
Gulf of Alaska (Pike 1959; Fiscus, et al., 1977); 55 other sightings have
been reported between 1958 and 1975 (Fiscus, et al. , 1977).
Few stomach samples have been examined in the northeastern Pacific
region. Five from California coastal waters reported in Fiscus and Niggol
(1977) had consumed fish (northern anchovy, 45-95%, and Pacific hake, Mer-
luccius productus, 5-10%) and squid (Gonatus sp.). Another specimen from
California was reported to have fed upon squid (Scheffer 1950b) while
another from that area had consumed Pacific sardine (Sardinops sagax)
(Higgins 1919). —
Lanternfishes were the main fish (77% of total stomach contents volume)
of the prey consumed by 13 Pacific white-sided dolphins examined by Wilke,
et al. (1953); anchovy, Engraulis japonica, and chub mackerel, Scomber
Japonicus, were the other prey fishes. Squid beaks and eye lenses, probably
from Watasenia scintillans. composed only 7% of the stomach contents volume.
Orca (Killer Whale)
Undoubtedly the most ubiquitous toothed whale in north Puget Sound and
the Strait of Juan de Fuca is the orca. As of 1977, approximately 115 whales
occurred in this area, of which 65-70 could be considered residents (compos-
ing four distinct pods designated J, K, L 8, and L 10) and the remainder
transients (composing seven pods, A5, E, G, M, N, 0, and Q) (Bigg , et al.,
™ ™. !eCent Si8btl'n8s su8gest that the resident pods may now comprise
75-80 individuals (Balcomb 1978; K. Balcomb and R. Osborne, pers. comm.).
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There was no distinct pattern to their distribution and movements (M.S.
Bigg, Pac. Biol. Sta., pers. comm.), which appeared to be related directly
to feeding or the search for food (Balcomb and Goebel 1976). Only J pod
appeared to be completely residential in Puget Sound, the Strait of Georgia,
and eastern Strait of Juan de Fuca, having a range of about 210 nautical
miles. The other three pods apparently resided in the region 8-9 months of
the year, entering and leaving through the Strait of Juan de Fuca; there is
no information on their movement along the outer coast. The transient pods
occurred infrequently, moving into and out of the northern Strait of Georgia
from the north, and have never been seen inside Puget Sound proper. Several
aggregations of 3 to 17 animals were sighted, 25-100 km off Westport by
Wahl (1977) between May and September.
Scheffer and Slipp (1948) summarized orca food habits and feeding beha-
vior known to that time. A diverse array of marine mammals, sea birds,
fishes, and cephalopod molluscs were the principal prey taxa described.
Smaller individuals and nursing calves of humpback (Megaptera novaeangliae),
finback (Balaenoptera physalus), and gray (Eschrichtius robustus) whales,
harbor porpoise (Phocoena phocoena), hair seal, black brant (Branta nigri-
cans), greenling (Hexagrammidae), lingcod, salmon (Oncorhynchus sp.), and
squid were the specific organisms itemized.
Nishiwaki and Handa (1958) were the first to evaluate orca food habits
on a large scale. Their analysis of the stomach contents of 364 orcas from
the coast of Japan indicated that the whales fed mostly on fishes and
cephalopods, but also on large numbers of cetaceans and pinnipeds.
Detailed information on orca food habits was assembled by Rice (1968).
He summarized the stomach contents of ten orcas collected in offshore waters
of the eastern North Pacific between Kodiak Island, Alaska, and San Miguel
Island, California. Eight of the ten stomachs examined contained marine
mammal remains, specifically California sea lion (Zalophus californlanus),
northern sea lion (Eumetopias jubatus), elephant seal (Mirounga anguisiros-
tris), harbor porpoise, Dall porpoise (Phocoenoides dalli), and minke whale
(Balaeroptera acutorostrata), which made up over 75% of the total prey.
Three stomachs contained fish, including Pacific halibut (Hippoglossus
stenolepis), opah (Lampris regius), and carcharinid sharks. Only one speci-
men contained cephalopod remains. Martinez and Klinghammer (1969) generally
itemized orca prey organisms, which included 10 species of cetaceans, 8
pinnipeds, 11 teleost fishes, 6 other vertebrates, and 3 elasmobranch fishes.
One specimen from California examined by Fiscus and Niggol (1965) was pre-
sumed to have eaten one California sea lion, one cetacean, and as many as
four elephant seals.
Other recorded prey organisms of orcas have included northern fur seal
(Callorhinus ursinus) in the western North Pacific (Bychkov 1967); bearded
seal (Evignathus barbatus) and walrus (Odobenus rosmarus) in the Bering Sea
(Zenkovich 1938); eagle ray (Myliobatis sp.) off Brazil (Costello 1977);
leatherback sea turtle (Dermochelys coriacea) in the Lesser Antilles (Cald-
well and Caldwell 1969); and minke whale along the northwest coast of
Vancouver Island, B.C. (Hancock 1965).
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Recent observations of orca feeding activity and collections of prey
remains made by Pacific Biological Station biologists off southeastern
Vancouver Island identified chinook (Oncorhynchus tshawytscha), coho (0.
kisutch) and sockeye salmon (0. nerka), and anadromous (steelhead) trout
(Salmo gairdneri) as important food items in the region of concern (M. Bigg
and G. Ellis, unpub. data).
Existing reports of orca food habits imply that pinnipeds and small
cetaceansconstitute the preferred prey organisms and the staple element of
the orca diet in most regions of the world. Rice (1968) has pointed out,
however that, "in Puget Sound, where the killer whale population is probably
denser than anywhere else in the world,the marine mammal population (mostly
harbor porpoise, Minke whale, Pacific harbor seal, and a few northern sea
lions) does not appear large enough to provide a major proportion of the
killer whale's diet. It is widely believed that runs of spawning salmon are
a major food there during the summer, but no data are available to support
this assumption." As supported by Bigg's recent evidence, salmon and
abundant schooling forage fishes such as Pacific herring (Clupea harengus
pallasi) and Pacific sand lance (Ammodytes hexapterus) may be the most stable
trophic contribution to the orca's diet in northern Puget Sound and the Strait
of Juan de Fuca, supplemented by such pinnipeds and small whales as they may
encounter.
Feeding behavior may also vary from pod to pod. Balcomb and Goebel
(1976) identified L pod as being more aggressive in its food habits than
others; i.e., it was the only one observed to take marine mammals. The L pod
typically frequented the waters on the west side of Vancouver Island and the
Olympic Peninsula, venturing periodically into inland waters through the
Strait of Juan de Fuca.
Gray Grampus or Risso's Dolphin
Stroud (1968) documents one of the few records of gray grampus dolphin
in Washington. His description of a young male specimen which washed ashore
at Makkaw Bay (northwest, exposed coast of Olympic Peninsula) included
contents of the stomach, which, though the animal had been dead about a
month, included 44 (55 g) identifiable squids. Seven taxa were represented;
Gonatus fabric!, two other gonatids, and Chiroteuthis verangi were the most
prominent forms but Onychoteuthis banksi and Octopodoteuthis sicula were also
present. Several verified records and several credible sightings of gray
grampus dolphin exist for British Columbia which is apparently the northern
limit of its range (Guiguet and Pike 1965; Pike and MacAskie 1968); no food
habits were determined, however. Wahl (1977) reported three sightings, one
in October 1974 and two in September 1976, of gray grampus in groups of 40 to
60, often mixed with other species such as Pacific striped dolphin.
False Killer Whale
Scheffer and Slipp (1948) provided the only record of a false killer whale
in Washington and British Columbia, an animal stranded near Olympia (south
Puget Sound) in 1937. Its stomach contained some salmon remains.
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Shortfin Pilot Whale
Although sightings of Pacific pilot whales have occurred frequently,
especially in 1958 when there appeared to be a northward shift in distribution,
there were but a few verified specimens in the Washington and British Columbia
region (Pike and MacAskie 1968). They do not appear to move into the region's
coastal waters before mid-April (Fiscus and Niggol 1965). Sighting data
recently compiled by the Moclips Cetological Society's Orca Survey suggest
that five to ten groups may frequent Puget Sound each year, principally in
spring and summer (Rich Osborne, pers. comm.). No diet information was
reported.
Harbor Porpoise
Considered the most frequently seen cetacean in Washington State by
Scheffer and Slipp (1948) . harbor porpoise range the breadth of Puget Sound
and the Strait of Georgia, through the Strait of Juan de Fuca, and well
offshore Washington and British Columbia. They were frequently sighted by
Wahl (1977) close inshore of Westport and in Grays Harbor channel, usually
in groups of one to five animals. They have been captured in nets set on the
bottom as deep as 44 fm. When seen in Puget Sound they were often in groups
of two to five, occasionally ten to twelve. The 1977 Orca Survey, conducted
by the Moclips Cetological Society (Balcomb 1978) also reported seven
sightings of harbor porpoise in the San Juan Islands; compilation of their
total data, however, suggests that between 30 and 60 are seen each year in
northern Puget Sound (Rich Osborne, pers. comm.).
Scheffer and Slipp (1948) concluded from the contents of four stomachs
that, "the favorite foods of the harbor porpoise are probably fishes under
a foot in length; of slender form and soft flesh; lacking stiff spines and
armor; including types that commonly run in schools near, but not on, the
bottom. Such speedy swimmers as the salmon and trout; bottom dwellers;
heavily armed species like the rock-cod and sculpin, and invertebrates with
the exception of the squid, are probably not important in the diet of the
porpoise."
Five Pacific herring were found in the stomach of one female harbor
porpoise examined at Port Townsend, Washington, in May 1950 (Wilke and Kenyon
1952).
Pall Porpoise
Despite the high abundance of Ball porpoise in Washington and British
Columbia waters, second only to the harbor porpoise, few described specimens
existed (Scheffer and Slipp 1948; Pike and MacAskie 1968). Ball porpoise
appeared to be most abundant offshore and common in the Strait of Juan de
Fuca, though seldom seen in either the Strait of Georgia or Puget Sound
proper. Fiscus and Niggol (1977) observed Ball porpoise six times during
April 1959, all within 50 km of shore. Sightings of Ball porpoise were made
on 24 of the 34 cruises between July and October described by Wahl (1977),
but sightings occurred on only 2 of 12 cruises between mid-April and mid-May.
The majority of these observations were made more than 50 km offshore and
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were of groups of 3 to 6 porpoise. Dall porpoise generally travel in
schools of 5 to 14 (usually 6) but are encountered inshore in groups of 30 to
100 in spring and fall. Eight sightings of Dall porpoise were reported in
the 1977 Orca Survey (Balcomb 1978), principally along western Whidbey Island
between Rosario Strait and Possession Point. More recent assessment of the
survey data indicates that three to four groups, comprising 40 to 60
individuals, of Dall porpoise frequent Puget Sound (Rich Osborne, pers. comm.).
Pacific herring were the sole prey found in the stomachs of four Dall
porpoise taken in Queen Charlotte Sound, B.C., by Cowan (1944). The stomachs
of the Dall porpoise collected in 1937 between Sauk Inlet and Port Angeles
along the Strait of Juan de Fuca contained fish and squid beaks and unidenti-
fied "eyes" (Scheffer and Slipp 1948). Of five specimens collected offshore
Washington and British Columbia between 1957 and 1959, the stomachs of two
were empty, two had "mostly squids," and one had "mostly herring." Stomach
contents of nine Dall porpoise collected off the California and Washington
coasts between 1964 and 1972 (Stroud et al. 1964-72) contained 4 species of
pelagic fish, one flounder and six species of squid. Fiscus and Niggol (1965)
examined the stomach contents of five specimens collected off northern
California; one stomach was empty, the other four contained only remains of
squid.
The stomach contents of 25 Dall porpoise from Monterey Bay were examined
by Loeb (1972). She found that hake (Merluccius productus), juvenile rockfish,
and the squid Loligo opalescens were the prevalent prey between May and
December, and northern anchovy and Pacific herring became important in winter.
During the period between October and April other fish species became
important: Myctophids (including predominantly Tarletonbeania crenularis),
night smelt (Spirinchus starksi), Pacific sanddab (Citharichthys sordidus),
spotted cusk-eel (Otophidium taylori), pompano (Petrilus simillimus), juvenile
sablefish (Anoplopoma fimbria), California smoothtongue (Bathylagus stilbius),
pinpoint lampfish (Lampanyctus regalis), snailfish (Liparis sp.), eelpouts
(Zoarcidae), grenadiers (Macrouridae), and eels. Pelagic cephalopods found
in the stomachs included the squids Abriolepsis felis, Gonatus sp., and
Onychoteuthis boreali-japonicus, and the octopus Octopus bimaculatus.
Capelin (Mallotus villosus) were the only prey found in the stomachs
of two porpoise from the Gulf of Alaska examined by Scheffer (1953). Squid
predominated in the stomach contents of 148 Dall porpoise from the Bering
Sea and North Pacific examined by Mizue, et al. (1966); fish, including
sockeye salmon, and shrimp were secondary components of the diet.
Ninety-eight percent of the total volume of the stomach contents of four
Dall porpoises collected off Japan by Wilke et al. (1953) was squid,
predominantly Ommastrephes sloani pacificus; a gadid fish, Laemonema
morosum, composed the remainder of the contents. Lanternfishes (predominantly
Notoscopelus sp. and Tarletonbeania taylori as well as Diaphus sp.,
Lampanyctus sp., Myctophum sp. and other unidentified myctophid species) and
a fish species of the family Sudidae (Paralepis sp.) were the principal prey
of seven Dall porpoise described by Wilke and Nicholson (1958); squids
(including Watasenia scintillans and Ommastrephes sloani pacificus), though
frequently fed upon, did not provide a high percentage of the stomach contents
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volume.
Beluga Whale
Scheffer and Slipp (1948) included a 1940 report of a white or beluga
whale observed in south-central Puget Sound. This was an extremely rare
occurrence for a whale which was previously not seen south of Cook Inlet,
Alaska.
Belugas apparently have a broad prey spectrum. Kleinberg, et al. (1964),
reported prey including arctic cod (Boregadus saida), capelin, salmon,
flatfish (Pleuronectidae), herring, and crustaceans. Johnson, et al. (1966),
examined the stomachs of two belugas taken in the Cape Thompson region of
Alaska and described the contents as arctic cod and at least three species
of shrimp.
Pygmy Sperm Whale
Very few specimens of this species were reported from the Pacific
coast of North America, though one from the central coast of Washington was
examined in 1942 (Scheffer and Slipp 1948). Although it had been dead for
two weeks, its stomach still contained evidence of 15 squid, at least 10 fish
(including Pacific sandfish, Trichodon trichodon), crab, and shrimp (including
Pasiphaea pacifica, Pandalus borealis?, and Pandalopsis dispar?).
Gray Whale
Gray whales pass close inshore through Washington and British Columbia
coastal waters during their migration between their calving grounds along
southern California and northern Mexico and the summer feeding grounds in the
Bering Sea. They usually appear during their northward migration between
February and May and in December and January during their southward migration
(Pike and MacAskie 1968), traveling individually or in groups of two, three,
or four. Wahl's (1977) four sightings all occurred in May and were
typically close inshore. It was primarily during the northward migration in
spring that the Indian whalers of the Pacific Northwest concentrated on the
gray whale, highly susceptible to their harvest because of its small size,
moderate speed, and tendency to pass close inshore (Scammon 1974; Scheffer
and Slipp 1948). They generally cross the mouth of the Strait of Juan de
Fuca in a line between Cape Flattery and Pachena Point, Vancouver Island
(Hatler and Darling 1974; Hart 1977), or Carmanah and Cape Beale (Pike 1962).
The incidence of gray whales venturing inside the Strait of Juan de Fuca is
not high. One was reported at Point Defiance, in south-central Puget Sound,
in about 1938, and recently a young calf was discovered floating dead in
Possession Sound (Seattle P-I, June 21, 1978), and one beached near Neah Bay
in August 1978. Included in Balcomb's (1978) 1977 Orca Survey were eight
sightings of gray whales, two in the Port Angeles vicinity, two around
Bremerton, and four in southern Puget Sound. In general, 20 individuals may
be assumed to frequent Washington's inland waters annually (Rich Osborne,
pers. comm.).
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Scammon (1874). Pike (1962), and Rice and Wolman (1967, 1971)
maintain that in general gray whales do not feed significantly along the
southern section of their migration route; only one of the 84 stomachs
examined by Rice and Wolman (1967) contained prey organisms, zoea of the crab
Pachycheles rudis. Wilke and Fiscus (1961) . Hewell and Huey (1930), Rau and
Schevill (1974, citing Ken Balcomb, pers. comm.), and Hart (1977), however,
have provided indications of feeding activity or significant stomach contents
for some gray whales during the migration along the Pacific Northwest coast.
Planktonic euphausiids (Euphausia pacifica) and nektonic fishes (rainbow
smelt, Osmerus mordax?, northern anchovy)were the prevalent prey in these
instances. The stomach of the dead calf from Possession Sound was reported
to contain crab zoea (Bob Everitt, NOAA, pers. comm.).
On their usual feeding grounds in the Bering and Chukchi seas (Pike
1962), benthic and epibenthic organisms are the prevalent food, specifically
gammarid amphipods but also other epibenthic crustaceans such as mysids,
cumaceans, and isopods (Pike 1962; Rice and Wolman 1967, 1971; Tomilin 1957;
Zimushko and Lenskaya 1970). Wilke and Fiscus (1961) described the feeding
whales making large muddy blotches in the water as they came to the surface
to blow, implying that, "in feeding along the bottom the whales gathered mud
along with food and were expelling it through their baleen as they rose to
the surface." Tomilin (1957) supposed that the whales fed by scooping and
plowing their mouths into the bottom, but Ray and Schevill (1974), from
observations of a captive juvenile gray whale, documented a bottom-sweeping
feeding sequence wherein "the whale rolls over far enough so that the cheek
is about parallel with the bottom, and the lip is opened as the tongue,
pressing against the palate, pushes the gular region away so that it expands,
producing an inflow which brings in the epibenthic food. Then the tongue
relaxes and the gular musculature tightens, reducing the size of the mouth
cavity and expelling water; the food is trapped in the baleen fringes. We
do not know exactly what happens next: perhaps a slight renewed suction of
water removes the food from baleen fringes, and swallowing presumably follows."
This behavior, if real, would explain the asymmetric distribution of
barnacles along the head, producing predominantly "right-sided" (feeding on
left side) animals (Kasuya and Rice 1970).
Finback (Fin) Whale
Historically, fin whales were the first or second most abundant whale
of the Pacific Northwest coast. Pike and MacAskie (1969) indicated that fin
whales were the most abundant of the baleen whales found along the coast of
British Columbia; they were the second most important species in the commercial
catch there and off the Washington coast (Scheffer and Slipp 1948). Several
reports exist of fin whales sighted or captured in Puget Sound and the Strait
of Georgia. Although many of the adult whales appear to be migrants traveling
between summer feeding grounds in the North Pacific and winter breeding grounds
to the south, young animals may reside off the Washington and British Columbia
coast during the summer (Pike and MacAskie 1968).
While the little that is known of fin whale feeding in our region is
to be found principally in Pike (1950), reports of their food organisms in
the North Pacific include the expansive work by Nemuto (1959) , and Andrews
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(1909), Bethesheva (1954, 1955), Mizue (1951), Nemoto and Kasuya (1965), and
Thompson (1940). Nemoto (1959) and Tomilin (1954) showed that fin whales
have the second greatest number of baleen plates and the third smallest baleen
fringe diameters of all the baleen whales in the North Pacific. Fin whales
also have comparatively coarse baleen fringes, similar to those in blue whales.
They found that euphausiids and calanoid copepods served as the primary food
items and pelagic schooling fishes (primarily capelin, juvenile walleye pollock,
Theragra chalcogramma, and Pacific herring) provided secondary contributions.
Thysanoessa inermis and _T. longipes were the principal euphausiid species, and
Calanus^ cristatus and ^C. plumchrus the principal copepod species occurring in
the samples examined by Nemoto (1959) . Copepods predominated in the stomachs
of whales taken offshore whereas euphausiids predominated in specimens
captured along the coast (Nemoto and Kasuya 1965). Euphausiids CT. inermis)
were the dominant prey in 48 of the 50 stomachs with food examined from
Akutan, Alaska, in 1937 and 1938; walleye pollock (Theragra chalcogramma)
and calanoid copepods (Calanus cristatus) predominated in the other two
stomachs (Thompson 1940). Fin whales were also feeding on euphausiids
(Euphausia pacifica, Thysanoessa spinifera) off the coast of California in
1937; only one of the 14 stomach samples had copepods as the prevalent prey
(Thompson 1940).
Sei Whale
For many years the sei whale was largely ignored by the commercial
whalers off the Pacific Northwest coast because of its small size and poor
yield of oil, but it became more important with the decline of the fin whales.
Of British Columbia's commercial catch from 1962 through 1966, 57% was
composed of sei whales (Pike and MacAskie 1969). At the Bay City whaling
station, however, only 21 sei whales were taken between 1911 and 1925
(Scheffer and Slipp 1948). There are no confirmed reports of sei whales
appearing in the inland waters of Puget Sound.
Amongst the baleen whales of the North Pacific, sei whales have an
intermediate number of baleen plates but have one of the lowest diameters of
baleen fringes, second only to young right whales (Tomilin 1954; Nemoto 1959).
The fine filtering capability of the sei's baleen morphology is reflected in
the predominance of small prey organisms, almost exclusively calanoid
copepods. Nemoto (1959), Nemoto and Kasuya (1965), and Kawamura (1973)
illustrated that calanoid copepods, including Calanus cristatus, C\ plum-
chrus, C. pacificus, and Encalanus bungi bungi, were the primary food
species, £. cristatus being more dominant in offshore waters than the others.
Other prey organisms occurring less frequently in the stomach contents of sei
whales were euphausiids (predominantly Euphausia pacifica), saury, chub
mackerel, Japanese sardine, Sardinops melanostica, and squid, Ommastrephes
sloani pacificus (Nemoto 1959; Kawamura 1973). Fish appeared prominently in
the diets of whales collected south of 40°N.
The stomach of one sei whale examined at Port Hubron, Alaska, in 1937
contained copepods, Calanus cristatus, and a few amphipods, whereas 12 taken
in coastal California had eaten only euphausiids (Thompson 1940).
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Minke (Little Piked) Whale
Because minke whales, the smallest of the baleen whales occurring along
the Pacific Northwest coast, were not favored by the commercial whalers, the
historical records did not reflect their actual abundance. Wahl (1977)
included one report of a minke 179 km offshore Westport in September 1976.
Collins (1892) and Waterman (1920) reported that the native whalers off Cape
Flattery and the Strait of Juan de Fuca did take minkes. Scammon (1874)
reported the first specimen taken in Puget Sound, a 27-foot female washed
ashore in Admiralty Inlet. Scheffer and Slipp (1948) included four other
verified reports of minke whales in various locations off Puget Sound,
including Whidbey Island, McAllister Creek (Nisqually Reach), Snohomish River,
and Deception Pass, and one at Waadah Island off Neah Bay. Pike and MacAskie
(1969) described five records of minke whales along the British Columbia coast,
but none from inside waters. Only two records of minke whales occurred in the
commercial whale statistics from British Columbia (Pike and MacAskie 1969),
none from Washington (Scheffer and Slipp 1948), and the one stomach of these
which was examined was empty. Balcomb's (1978) 1977 Orca Survey also included
21 sightings of minke whales, all occurring in northern Puget Sound and
Admiralty Inlet. One was sighted in southern Possession Sound west of Everett.
Recent assessment of the survey's sighting data suggests that between 5 and 20
minke whales occur annually in the region's inland waters (Rich Osborne,
Moclips Cetological Society, Orca Survey, pers. comm.).
Having an average of 280 baleen plates (per side, range 260-300),
minke whales are in the group of right and gray whales, but they have baleen
fringe diameters closer to sei whales and are classified as a swallowing
(gulping) type (Nemoto 1959). Accordingly, their diet elsewhere in the North
Pacific is quite catholic for a baleen whale, including euphausiids (Euphausia
pacif ica, Thysanoessa inermis, T_. longipes, and T_. raschi); fish (Pacific sand
lance, walleye pollock, and saury)jcopepods (Calanus finmarchicus); and
squid (Nemoto 1959; Omura and Sakiura 1956).
Blue Whale
Prior to the protective regulations imposed by the International
Whaling Commission (IWC) in 1965, blue whales were one of the most prized
catches of the commercial whalers operating off the Pacific Northwest coast.
Because of their large size, speed, and tendency to pass well offshore, they
were not overly abundant in the catches; only 13 were taken during the
operation of the Bay City whaling station (Scheffer and Slipp 1948) and 320
in British Columbia waters (Pike and MacAskie 1969). There were no reports of
blue whales naturally occurring within the region's inland waters.
Blue whale baleen is one of the coarsest filtering apparatuses amongst
the baleen whales, having the highest number of baleen plates, the largest
diameter baleen fringes, and the second lowest number of baleen fringes
(Nemoto 1959). In the North Pacific their prey is almost exclusively the
larger euphausiids (Euphausia pacifica, Thysanoessa inermis, and T\ longipes),
and only incidentally copepods (Mizue 1951; Nemoto 1959). Thompson's (1940)
analysis of blue whale stomachs brought to Akutan and Port Hobron, Alaska,
whaling stations substantiated their dependence upon euphausiids (primarily
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^T. inermis) in that region and those reported from California in that source
were identical.
Humpback Whale
Humpbacks once made up the majority of whales taken commercially off the
coast of Washington and British Columbia, but under heavy exploitation there
and in California and Alaska they declined rapidly until the early 1960s
when most of the whaling operations were forced to terminate (Scheffer and
Slipp 1948; Pike and MacAskie 1969). Humpbacks were placed under IWC
protection in 1966 and 1967- They appeared to represent migrants which
veered inshore during their migration to Alaska in July and August. The
wandering humpbacks often ventured into the inland waters of Puget Sound and
the Strait of Georgia and the Strait of Juan de Fuca; Scheffer and Slipp
(1948) described three such occurrences in south and central Puget Sound.
Recent compilation of the Orca Survey's (Moclips Cetological Society) sighting
data illustrates that about two whales venture into Puget Sound annually
(Rich Osborne, pers. comm.).
Unfortunately, despite the frequency of occurrence of humpback whales,
few stomachs were examined in the region. Classified as a "swallowing
(gulping) type" like blue whales by Nemoto (1959), humpbacks have an inter-
mediate number of baleen plates, mid-range baleen fringe diameters, and a
number of baleen fringes similar to the blue, fin, and minke whales. Pike
(1950) described the prevalence of euphausiids (Thysanoessa spinifera,
Euphausia pacifica) in humpback stomachs in British Columbia, and Hewell and
Huey (1930) listed the euphausiid Euphausia pacifica and Pacific sardines.
In the North Pacific, euphausiids (primarily Thysanoessa inermis) were the
dominant prey organisms, but schooling pelagic and epipelagic fishes
(especially Atka mackerel, PIeurogrammys monopterygius. capelin, Pacific
sand lance, and walleye pollock, Theragra chalcogramma) were also prominent.
Thompson (1940) described the stomach contents of humpbacks taken in the
western Gulf of Alaska as principally euphausiids, Thysanoessa inermis and
T_. gregaria, and surf smelt, Hypomesus pretiosus.
North Pacific Right Whale
Records of right whales along the coast of Washington originated
primarily from unverified reports of native catches (Waterman 1920), but
four were taken during the commercial whaling off British Columbia (Pike and
MacAskie 1969). Scammon (1874) suggested that they were once found off
Oregon, often in high numbers. Fiscus and Niggol (1965) recorded three
right whales off northwest Washington in April 1959. Gilmore (1956) suggested
that the coastal waters of California, Oregon, Washington, and British
Columbia were wintering grounds for right whales during former periods of
abundance. Although no records exist of right whales occurring in the region's
inland waters, a recent sighting placed three whales off Cape Flattery
(Rice and Fiscus 1968).
Neither food habits nor feeding behavior have been documented for this
region. Right whales have a low number of baleen plates and the lowest
diameter and highest number of baleen fringes of all the baleen whales, and
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are considered a unique skimming type of feeder (Nemoto 1959). As a result,
the smaller planktonic crustaceans such as the copepods Calanus plumchrus and
C^. finmarchicus form the bulk of their diet while larger euphausiids were
incidental.
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D-2. Pinnipeds
Marine mammals from two pinniped families are represented in Puget
Sound—Otariidae, the eared seals, and Phocidae, the earless seals. Northern
fur seal, northern or Steller's sea lion, and California sea lion are Otarii-
dae; Pacific harbor seal, Phoca vitulina richardsi, and northern elephant
seal are Phocidae. Only northern sea lions and Pacific harbor seals are now
prevalent in the Strait of Juan de Fuca and northern Puget Sound. The follow-
ing species accounts document the trophic relationships of all pinnipeds
reported from the region; however, the preceding food web discussion considers
only the two prevalent species.
Species Accounts
Northern Fur Seal
Transient fur seals, migrating between their summer breeding grounds
in the Bering Sea and their winter feeding grounds off California, occur along
the Washington and British Columbia coasts in March, April, and May. Wahl
(1977) reported sightings on 14 of 47 trips offshore Westport, Washington,
mostly in May. Inshore winter residents include mostly 1- to 3-year-old
seals, the older females moving farther south (Spalding 1964). Commercial
sealers took large numbers offshore until the North Pacific Fur Seal Treaty
of 1911, and native Indians were reported to have captured nearly 50,000 fur
seals off British Columbia between 1912 and 1940 (Pike and MacAskie 1969).
Apparently, many fur seals venture into the region's inland waters; Manzer and
Cowan (1956) listed sightings in British Columbia's coastal waters through
1955.
Stomach contents analyses on northern fur seals in the Pacific Northwest
region were performed as early as the 1930s when Clemens and Wilby (1933)
and Clemens, et al. (1936), examined 593 fur seal stomachs from off the coast
of British Columbia. They found that 84% of the volume of stomach contents
was Pacific herring.
Kenyon's (1950a) synopsis of early food habits data on fur seals taken
in coastal waters between Washington and southeastern Alaska in spring and
early summer prior to 1950 indicated that Pacific herring composed almost
three-quarters of the total prey composition by weight; other fish, including
eulachon, Pacific salmon, Pacific sardine (pilchard) and Pacific sand lance
were prey of secondary importance.
Detailed collp.ctions and examinations initiated as a result of the 1957
Interim Convention on Conservation of the North Pacific Fur Seals included
2,113 fur seal stomachs procured from 1958 to 1961 in British Columbia's
coastal waters (Spalding 1964). Clupeid fishes (Pacific herring, Pacific
sardine, and northern anchovy) and squid (Loligo opalescens, Gonatus magister)
formed the basis of the fur seal diet. Whereas the adult seals migrating off-
shore the British Columbia coast fed principally upon clupeids, the diet of
young seals residing in protected coastal waters from January through mid-April
shifted from squid, ratfish, Hydrolagus colliei, and sablefish to only the squid
Gonatus magister.
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The few young animals left in the region in summer had consumed Pacific
herring, Pacific hake, Pacific cod, Gadus macrocephalus, and various squid
species; it was at this time that species of Pacific salmon entered the diet
to any significance, 10% of the total food intake. Age specific food data
also indicated that larger prey (Pacific salmon, Pacific cod, Pacific hake,
rockfish, and shad, Alosa sp.) became increasingly important with increasing
age of the predator.
The stomachs of fur seals taken off the coast of Washington contained,
in order of decreasing volume, walleye pollock, eulachon (Thaleichthys
pacificus), American shad (Alosa sapidissima), rockfish, Pacific herring, and
northern anchovy (Schultz and Rufn 1936; Wilke and Kenyon 1954). Northern
anchovy, rockfish, capelin, and several species of Pacific salmon
(Oncorhynchus kisutch, £. tshawytscha) combined to form 92.3% of the total
food volume in 190 fur seals collected off the coast of Washington in 1969
(Fiscus and Kajimura 1971). Seals taken at the entrance to the Strait of
Juan de Fuca, however, appeared to have fed principally upon Pacific herring.
Wilke and Kenyon's (1952) collections of 148 fur seals from southeastern
Alaska in 1950 and 1951 showed that wintering female fur seals preferred
Pacific herring (99.5%) over walleye pollock (0.5%) and squid (Loligo sp.,
trace) in that region.
Capelin, eulachon, and Pacific sand lance appear to assume greater
importance as the migrating fur seals move into the western Gulf of Alaska
and eastern Aleutian Islands (Taylor, et al., 1955; Wilke and Kenyon 1957),
and are supplemented by walleye pollock once the seals enter their summer
residency in the Bering Sea (Lucas 1899; Taylor, et al., 1955; Wilke and
Kenyon 1954). Pacific sand fish (Trichodon trichodon) composed 94.2% of the
total prey volume and 99% of the total prey numbers from stomach contents
of 27 fur seals collected at St. Paul Island in the Pribilof Islands, and
sturgeon poacher, Agonus acepenserinus, composed most of the rest (Kenyon
1956).
Stomachs of 445 fur seals captured in the pelagic waters off northern
Japan were reported to contain predominantly lanternfishes, 55.3% by volume,
and squid (Ommastreph.es sloani pacificus, Watasenia scintillans), 43.5%
(Wilke 1951). Stomachs of 559 fur seals collected in November in the Sea
of Okhotsk contained Asian greenling (Pleurogrammus azonus), Pacific sand
lance, smelts (Osmeridae), walleye pollock, and Pacific salmon (Far Seas
Fisheries Research Laboratory 1979). Data collected by USSR (VINRO/TINRO
1977) indicated that squid (Gonatus magister, Onychoteuthis banksi). and
salmon were important prey organisms of fur seals feeding off the southeast
coast of Hokkaido in 1975, and squid (Onychoteuthis banksi) and lantern-
fish of fur seals feeding near the eastern shore of Honshu in 1976.
In general, fur seals feed upon epipelagic and neritic schooling fishes
and squid, usually consuming them whole underwater. Larger prey such as
lingcod (Ophiodon elongatus), Pacific salmon, and rockfish are often brought
to the surface where they are vigorously shaken apart (Spalding 1964). In
almost every region, feeding appears to occur principally at night when many
prey species have migrated closer to the surface (Wilke 1951; Fiscus and
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Kajimura 1971; Wilke and Kenyon 1954; Fiscus, et al., 1963; Spalding 196A).
Estimates of daily food consumption varied from 5% to 7% of the total body
weight with an observed maximum of 10% (Spalding 1964).
Because of the composition and abundance of neritic schooling fishes
in the Strait of Juan de Fuca, it is probable that fur seals feeding in that
region would be utilizing Pacific herring, Pacific sand lance, surf smelt,
longfin smelt (Spirinchus thaleichthys), immature Pacific salmon, and northern
anchovy. Some demersal fishes such as Pacific tomcod (Microgadus proximus)
and Pacific cod would probably also enter the diet incidentally.
Northern or Steller's Sea Lion
Northern sea lions reside and breed along the exposed coast of the Pacific
Northwest, principally on the Scott Islands and Cape St. James in British
Columbia. A 1961 census in British Columbia indicated approximately 1,500
pups and 4,500 adults residing in the province's waters (Spalding 1964).
Bigg's (1973) report of California sea lion abundances on southern Vancouver
Island included data on northern sea lions occupying the same haulout areas;
more than 953 individuals were observed at peak abundance, occurring in
December.
Wahl (1977) reported them far offshore the coast of Washington and
they are commonly dispersed into the inland waters of Puget Sound and the
straits of Georgia and Juan de Fuca when not occupying the rookeries in
fall and winter. Preliminary results from NOAA-MESA-sponsored aerial
surveys in northern Puget Sound, conducted between November 1977 and June
1978, indicated a maximum abundance at Race Rocks (southern tip of Vancouver
Island) of approximately 260 individuals. Abundances declined rapidly after
April when the majority of the animals departed Puget Sound (Bob Everitt,
NOAA, unpubl. data).
The stomach contents of northern sea lions collected off the British
Columbia coast by the Fisheries Research Board of Canada included a diverse
spectrum of large prey, principally octopus, rockfish, walleye pollock,
Pacific cod, Pacific hake, and spiny dogfish (Squalus acanthias) (Spalding
1964). Rockfish were the most common prey throughout the year, whereas
Pacific herring was a staple prey in winter, walleye pollock in summer, and
rockfish, Pacific salmon, walleye pollock, and Pacific hake in fall.
Northern sea lions widely collected along the Gulf of Alaska had fed
principally upon walleye pollock (55% by volume), salmon (13.3%), starry
flounder (Platichthys stellatus), octopus, skate, and Pacific tomcod;
Pacific salmon, however, occurred in only two of the 15 stomachs examined
(Imler and Sarber 1947). Mathisen, et al. (1962). described the principal
dietary components of northern sea lions from the Shumagin Islands in the
northwestern Gulf of Alaska as including nearshore fishes (mainly greenlings,
Hexagrammidae, and rockfish) and invertebrates (bivalves, squid, and
octopus), occurring in 42% and 85% of the stomachs,respectively. Bulls
tended to consume fish more often than did cows and yearlings. There were
no obvious changes in diet during or after the pupping season. Stomach
contents of two sea lions from St. Paul Island in the Pribilofs were
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described in Wilke and Kenyon (1952) as being dominated by either Pacific
sand lance or Pacific halibut with additional contributions by Pacific cod,
walleye pollock, and starry flounder.
In general, northern sea lions feed predominantly upon large fish
occurring throughout the water column as well as small schooling fishes when
abundant in pelagic waters. Like the fur seal, sea lions prefer to bring
large fish to the surface where the prey is torn apart into edible pieces by
violent shaking (Spalding 1964). They also appear to be nocturnal feeders,
exhibiting a decline in mean stomach contents volume from a maximum at dawn
to empty 13.5 hours after sunrise. Daily food consumption has been estimated
to range from 2% to 4% of the total body weight (Scheffer 1958).
California Sea Lion
Although at the northern extremity of their reported range, California
sea lions have been sighted and collected along the west coast of Vancouver
Island, British Columbia (Cowan and Guiguet 1965; Guiget 1953), and thus
periodically may enter the Strait of Juan de Fuca to feed. Bigg's (1973)
censuses along southern Vancouver Island in 1971 and 1972 provided indications
of a population numbering at least 473 individuals occupying eight haulout
areas. Peak abundances were recorded in February. Bigg (1973) also reported
a haulout area in the Strait of Georgia on the southeastern side of Dodd
Narrows.
The NOAA-MESA surveys indicated a maximum of approximately 76 California
sea lions occupying the Race Rocks haulout area between December 1977 and
late April 1978. Like the northern sea lion, their numbers decline rapidly
thereafter as they depart Puget Sound for their breeding areas off California
and Mexico (Bob Everitt, NOAA, unpubl. data).
Investigations of the food habits of California sea lions in southern
California have established squid (Loligo sp.) and small fish (northern
anchovy and Pacific hake) as their main prey items in that region (Bonnot
1928; Scheffer and Neff 1948; Fiscus and Baines 1966; Peterson and Bartholomew
1967). Mate (1973), however, found no squid in the stomachs of California
sea lions collected on the Oregon coast in fall and winter.
Mate (1973) also documented a generally nocturnal feeding behavior for
the Oregon sea lion population that he closely observed, showing 88% of the
stomachs containing food in morning, 21% at midday, and 7% by evening.
"Feeding trips" were estimated to average 4.2 days.
Although there are no data existing for the diet of California sea lions
occurring in Washington and British Columbia waters, it could be assumed that
their diet would be based principally upon the schooling epipelagic fishes
(Pacific herring, northern anchovy, Pacific sand lance) and some of the more
midwater and demersal forms (Pacific hake, Pacific cod, and walleye pollock)
of the region.
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Pacific Harbor Seal
The most abundant and ubiquitous pinniped occurring in the protected
waters of Washington and British Columbia, Pacific harbor seals are most common
in estuaries and river deltas but are seen in shallow sublittoral waters along
the entire coastline and even ascend large rivers to reside in lakes (Cowan
and Guiguet 1965; Pike and MacAskie 1969). Hart (1977) reported one sighting
80 km offshore Westport, Washington.
No quantitative estimates of harbor seal populations have been made for
the region as a whole, although Pike and MacAskie (1969) estimated
approximately one seal per mile of shoreline—e.g., 17,000 seals—for coastal
British Columbia.
Aerial survey counts recently conducted by NOAA under the auspices of
the MESA program have provided the first detailed inventory of harbor seals
in northern Puget Sound and along the Strait of Juan de Fuca. The total
number of seals enumerated during these surveys varied between 643, taken in
December 1977, to 1,618 (excluding 143 pups), taken in August 1978 (Bob
Everitt, NOAA, unpubl. data). Of the 17 sampling areas subdividing the
region, the following eight had the highest abundances, in decreasing order:
San Juan Island, Smith and Minor islands, Patos Island to Lummi Island,
Rosario and Haro straits, Bellingham to Padilla Bay (all in north Puget Sound);
Protection Island, Dungeness to Sequim Bay, Becher Bay to Discovery Island
(along the Strait of Juan de Fuca).
Scheffer and Sperry (1931) were the first to quantitatively analyze
harbor seal stomach contents from Puget Sound. The 100 stomachs examined
contained, by volume, 93.6% fish (Pacific tomcod, flounder (Pleuronectidae),
Pacific herring, Pacific hake, sculpin (Cottidae), codfishes (Gadidae),
walleye pollock, and shiner perch, Cymatogaster aggregata), 5.8% molluscs
(squid and octopus), and 0.6% crustaceans (shrimp). Scheffer (1928) had
recorded the stomach contents of 22 adult harbor seals from southern Puget
Sound (Nisqually Flats) to be Pacific herring, Pacific tomcod, shiner perch,
sculpin, shrimp, crab, squid, octopus, skate, starfish, and flounder; only
two stomachs contained remains of Pacific salmon.
The most recent and comprehensive data on harbor seal food habits in
Puget Sound have been assembled by Dr. John Calambokidis (undergraduate
study project, Evergreen State College, 1978), based upon the composition
and abundance of fish otoliths (ear bones) in the feces deposited at haulout
areas. Pacific hake (73% of total numbers), plainfin midshipman (Porichthys
notatus^ 7%), and staghorn sculpin (Leptocottus armatus, 6%) predominated in the
overall diet combined for all regions, but there were distinct differences in
the dominant prey species for the different regions of Puget Sound. Pacific
hake and plainfin midshipman were most prevalent in the Hood Canal region;
staghorn sculpin and Pacific hake predominated in south Puget Sound; and
blackbelly eelpout (Lycodopsis pacifica), an unidentified eelpout (Lycodes sp.)
and Pacific herring were most important in the region of concern, north Puget
Sound (based on collections at Smith Island). Calambokidis' data also
indicate some seasonal changes in the diet composition. Pacific hake clearly
dominated harbor seal fish consumption in April and July through September 1977,
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plainfish midshipman predominated in early May. blackfin sculpin (Malacocottus^
kincaidi) in early June, and walleye pollock in late June.
In British Columbia, Fisher (1952) summarized the stomach contents of
50 harbor seals taken from the Fraser River, the Queen Charlotte Islands, and
the Skeena River between August 1945 and November 1946. Rockfish and octopus
were the most commonly occurring prey, but pink salmon (Oncorhynchus gorbuscha) .
Pacific herring, and other unidentified fishes composed most of the total
stomach contents volume. Fisher (1952) also indicated that there was
considerable temporal and spatial variability in the seals' diets and that
they appear to move along the Pacific coast in response to fluctuations in
abundance of preferred food organisms. Spalding's (1964) comprehensive
comparison of harbor seal feeding habits with those of fur seals and sea
lions along the coast of British Columbia showed a diet quite similar to the
sea lions, based upon salmon, octopus, squid, clupeids, and rockfish. The
contribution by Pacific salmon, however, was biased by a high number of
collections made in the vicinity of salmon spawning streams in fall. Although
seasonal sampling of harbor seals was inconsistent, it appeared that eulachon
may be most important in winter; octopus, Pacific herring, rockfish, and
salmon in summer; and salmon in fall.
Harbor seals in Alaskan waters have shown a similar feeding preference
for fish, including walleye pollock and Pacific herring in Prince William
Sound and eulachon at Copper River delta (Imler and Sarber 1947; Pitcher 1977),
and hexagrammids (Hexagrammos lagocephalus , Pleurogrammus monopterygius)
and walleye pollock in the Aleutian Islands (Wilke 1957; Kenyon 1965).
Walleye pollock (83% by volume) and Pacific herring (10%) were the predominant
food organisms of harbor seals sampled in the Sea of Okhotsk off Hokkaido
(Wilke 1954). Octopus and squid commonly appeared in the diet in all areas,
though never as a high percentage of the prey volume.
Harbor seal pups and juveniles have been reported to feed specifically
upon shrimp (Havinga 1933; Fisher 1952; Bigg 1973) and small fishes (Pitcher
1977) at a general increase in prey size with increasing predator size
(Spalding 1964). Unlike fur seals and sea lions, harbor seals do not appear
to be nocturnal feeders (Spalding 1964) . Daily food consumption by harbor
seals has been estimated at 3.7% (Pitcher 1977), 5% (Havinga 1933), and 6%
(Scheffer 1958) of the total body weight.
Northern Elephant Seal
Although the nearest breeding site of the northern elephant seal is
1,000 miles to the south, off southern California and Mexico, they have been
reported into the Gulf of Alaska, including a specimen found at Prince of
Wales Island in southeastern Alaska (Willet 1943) and several reports at
Middleton Island and Baranof Island (Fiscus et al. 1977). Wahl (1977)
reported three sightings between 50 and 65 km offshore Westport, Washington,
and numerous sightings and specimens were reported from British Columbia,
especially in Hecate Strait (Pike and MacAskie 1969) . The stomach of one
specimen recovered from the west coast of Vancouver Island contained hagfish.
The only feeding behavior information from the Puget Sound region is of an
N° P°lnt in n°rth-Central
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285
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289
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290
-------
APPENDIX E
SEASONAL DISTRIBUTION AND ABUNDANCE OF FOOD WEB NODES AND NUMBER
AND RELATIVE IMPORTANCE OF FOOD WEB LINKAGES CHARACTERIZING
NEARSHORE HABITATS OF NORTH PUGET SOUND
AND THE STRAIT OF JUAN DE FUCA
291
-------
Appendix Table E-l.
Distribution and abundance of food web nodes characterizing neritic habitats
of north Puget Sound and the Strait of Juan de Fuca.
Cherry Point
Anacortes
W. Whidbey I.
Burrows Bay
San Juan Is.
Port Angeles
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
3
3
1
1
3
4
1
1
1
1
1
3
2
1
1
1
1
1
1
Ik-rbivorcs
5
2
1
2
3
3
1
1
3
2
1
2
3
1
1
2
3
2
1
1
Hlxcd
1
1
1
1 1
1
1 1
1
1
1
111
111
1
1
1 1
1
1
Pl.inklivorcs
10
8 1
3
5
11
11 1
2
2
5
7
2
4
8
7 1
5 1
3
6
6
3
3
1
1
1
1
1
1
1
2
1
1
2
1
1
1
lionthivores PisCtvorcs
1
1
1
3
1
1
1
2
1
3
2
2
1
3
2
3
1
4
2
3
Terrestrial Non-
1 6
3
1
1 5
3
1
5
3
6
3
1
1 6
3
1
ToMl
nndi'K
21
22
11
14
20
28
8
9
12
18
10
10
19
23
14
13
13
22
12
11
-------
Appendix Table E-2. Number and relative Importance of food web linkages to trophic levels characterizing neritic habitats
of north Puget Sound and the Strait of Juan de Fuca. (1° - primary, 2° - secondary, 3° - tertiary,
Incid - incidental trophic linkages, Nn - number of food web nodes indicated on Table E-l.)
ro
VO
10
Cherry Point
Anacortes
W. Whidbey I.
Burrows Bay
San Juan I .
Port Angeles
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
p,-
P-S«
3
3
1
1
3
4
1
1
1
1
1
3
2
1
1
1
1
1
1
'•""' r.r."er» rli"
3* Incid 1* 2* 3" Incld 1* 2
5
2 1
1
2
3
3 1
1
1
3
2
1
2
3 1
1 1
1
3
3
2
1
1
• 3' Incld !• 2' 3' Incld 1* 2'
2
2 1
2
5
2
2 1
2
2
2
2
4 1
1
2
2
4
2
2
rlnviry
3' Incld
2
2
2
2
2
2
A
2
2
2
1"
2
3
4
4
3
2
1
2
3
4
2
4
4
41
5
2
4
3
1
2
2' 3' Incld
37 8
25 4
2
2 2
36 9
5 5 7
1 2
3 2
14 1
3 3
2 1
2 1
8 6
2 6
1
13 2
14 1
4 5
31 3
21 2
1' 2' J'
2
1
111
2
1 2
2
1 2
3
1 1
2
1 2
3
1 3
2
112
3
2 1
Incld
8
3
5
8
3
1
8
3
1
10
5
3
12
3
2
!•
10
9
6
8
9
11
2
5
7
8
4
8
11
10
8
7
8
7
3
4
2'
3
2
3
3
5
1
1
1
1
1
3
4
3' Incld
13 8
10 12
3 5
6 7
10 9
9 17
3 5
7 3
8 1
7 11
5 4
2 1
16 2
10 16
5 6
8 5
10 1
10 17
6 6
4 4
Totnl 1
"l
34
33
14
24
31
42
10
15
17
26
13
12
29
36
19
21
20
34
18
16
M No.
llnk.igtf
(Nj/Nn)
1.62
1.50
1.27
1.71
1.55
1.50
1.25
1.67
1.42
1.44
1.30
1.20
1.53
1.57
1.36
1.62
1.54
1.55
1.50
1.45
-------
Appendix fable E-3. Distribution and abundance of food web nodes characterizing rocky sublittoral habitats
of north Puget Sound and the Strait of Juan de Fuca.
S3
RCT.IOTI (location)
Cherry Ft.
(Barnes I.)
W. Whidbey I.
Burrows Bay
(Allan I.)
San Juan Is.
(Pt. George)
Strait of
Juan de Fuca
Composite
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
6
6
6
6
6
6
6
5
6
6
6
6
4
6
llcrblvorei
211
211
211
211
211
211
211
211
211
211
211
211
212
2 1 1
HUcd
1
1
1
1
1
1
1
2
Planktlvorcs
36 1
35 1
32 1
31 1
38 11
38 11
25 11
23 11
37 11
26 11
33 11
32 1
46 11
3 14 1
Ili'tlthivor
1
1
1
1
1
1
1
1
1
1
1
1
1
1
•cs
9
9
8
9
7
9
7
7
8
9
9
10
9
11
Piscivorcs
3
1 3
1 4
4
3
1 3
1 3
1 2
1 2
1 5
1 4
3
1 5
5 1
34
34
30
30
34
38
31
27
34
36
34
31
38
48
-------
Appendix Table E-4. Number and relative Importance of food web linkages to trophic levels characterizing rocky sublittoral
habitats of north Puget Sound and the Strait of Juan de Fuca. (1* • primary, 2° • secondary,
3° - tertiary, Incid - incidental trophic linkages, Nn - number of food web nodes indicated on Table E-3.)
Cherry Point
(Barnes I.)
W. Whidbey I.
Burrows Bay
(Allan I.)
San Juan Is.
(ft. George)
Strait of
Juan de Fuca
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
1' 2* 3' Incld
5
5
5
5
5
5
5
4
5
5
5
5
3
1' 2" 3' In
4
4
4
4
4
4
4
4
4
4
4
4
4
cli) 1' 2' 3' InclJ !•
1
1
1
1
1
1
1
1
1
1
1
1
1 1
2'
2
2
1
2
1
2
1
1
1
1
2
2
2
>• I:
9
8
8
9
8
9
6
6
8
6
9
9
10
od
neld
2
2
2
2
2
2
2
2
2
2
2
2
4
3 3
3 3
211
2 1
2 6
4 6
3 3
3 3
215
4 5
3 3
2 1
3 3
6
6
6
6
6
6
6
6
6
6
6
6
6
229
229
118
129
219
2 1 12
4 8
1 8
129
3 1 10
229
317
1 3 15
20
18
19
19
20
18
16
16
20
20
17
17
20
1
1
1
1
1
1
1
2
2
2
2
3
2
2
3
2
2
2
1
1
3
3
2
3
2
1
2
2
2
4
4
3 15
2 16
2 14
3 13
3 14
3 17
3 14
1 13
1 13
3 18
3 16
2 15
6 13
6 24
6 23
5 19
6 22
5 23
5 29
7 18
4 17
6 24
4 23
6 23
4 21
6 32
31
28
29
30
31
29
27
25
29
31
28
27
36
Tot.ll »
"l
76
73
67
71
73
80
66
59
72
76
73
67
87
x No.
llnkmci
(Nj/Nn)
2.24
2.15
2.23
2.37
2.15
2.11
2.13
2.19
2.12
2.11
2.15
2.16
2.29
-------
Appendix Table E-5. Distribution and abundance of food web nodes characterizing rocky and
cobble littoral habitats of north Puget Sound and the Strait of Juan de Fuca.
(SO
VO
ON
Rocky
Strait of Juan
de Fuca and
San Juan Is.
Cobble
Strait of Juan
de Fuca and
San Juan Is.
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
6
7
6
7
4
6
5
6
3
3
3
3
3
3
3
3
Herbivore";
2
2
2
2
2
1
2
2
Hixvd
2 2
2 3
2 2
2 3
2 1
121
121
121
10
9
9
8
6
5
5
6
Plankctvorcs
1
1
1
1
Ronthivores
1
1
1
1
1
1
1
1
14
13
12
14
10
10
11
10
Plscivores
1
1
1
1
2
2
2
2
41
41
38
41
32
33
34
35
Composite
12
35
-------
N)
IO
Appendix Table E-6. Number and relative importance of food web linkages to trophic levels characterizing rocky and cobble
littoral habitats of north Puget Sound and the Strait of Juan de Fuca. (1* « primary, 2° • secondary,
3* • tertiary, Incid - incidental trophic linkages, Nn - number of food web nodes indicated on Table E-5.)
Rocky
Strait of Juan
de Fuca and
San Juan Is.
Cobble
Strait of Juan
de Fuca and
San Juan Is .
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
6
7
6
7
3
4
4
5
n,v, „,,,„.
5 1
5 1
5 1
5 1
4
3
4
4
2 1
2 1
2 1
2 1
1
1
1
"r f d
1 22
1 24
1 22
1 33
2 4
2 4
2 4
2 4
114
214
114
114
1
1
1
2
16
16
16
16
3
3
3
3 4
2 4
1 7
2 4
2 3
2 2
1
1 3
21
19
16
16
9
6
17
9
1
6
1
7
15
15
13
17
11
10
11
10
11
12
12
11
2 17
1 18
2 15
2 17
8 9
7 10
9 9
9 13
9
9
12
10
6
5
4
5
38
37
33
33
24
22
33
24
19
23
19
25
26
25
25
26
Totnl 1
"l
83
87
79
85
65
84
71
68
x No.
2.02
2.12
2.08
2.07
2.03
2.54
2.08
1.94
-------
Appendix Table E-7.
Distribution and abundance of food web nodes characterizing gravel-cobble shallow sublittoral
habitats of north Fuget Sound and the Strait of Juan de Fuca.
ro
vo
oo
Cherry Point
(Legoe Bay)
Anacortes
(Cuemes S.)
W. Whidbey I.
Burrows Bay
(Alexander's
Beach)
(West Beach)
San Juan Is.
(Deadman Bay)
(South Beach)
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
5
4
5
4
4
5
5
3
5
5
5
4
4
5
5
5
5
4
5
4
4
5
5
4
4
4
4
4
Ht-rbtworos
1 1
2
1
2 1
2 1
1
2
1 1
2 1
2
1
1
1
1
1
1 1
1
1
HlKcd
1
1
3
1 2
3
3
2
1
2
3
2
1
1
1
1
2
2
2
2
3
2
1
3
1
1
4
2
4
3
5
5
5
3
3
4
4
4
2
2
3
3
3
3
4
2
4
5
3
4
4
5
5
4
Planktlvorcs
4
5
8
4
6
7
12 1
6
3
4
10 1
3 1
1
1
5
1
3
4
3
1
13 1
16 1
8 1
12
6
12 1
6 1
4 1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
3
2
8
9
6
6
8
3
6
6
13
9
5
4
10
4
3
9
10
6
4
11
16
7
6
11
9
8
risclvores
1
1
2
2
1
1
2
2
1
1
2
2
1
1
2
2
2
1
1
2
1
1
2
2
1
1
1
2
1 19
15
1 34
27
1 27
1 31
1 40
1 20
22
24
42
28
14
15
27
16
17
22
26
1 19
30
43
40
33
23
40
29
26
-------
Appendix Table E-7, cont'd
Port Angeles
(Dungeness
Spit)
(Morse Creek)
(Kydaka Beach)
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
IU rblvor.'s
5
4
3
5
6 11
6 1
4
4
4
4
3
3
MUtd
1
1
1
1
2
2
2
1
2
1
1
2
2
1
3
2
2
3
2
2
2
2
2
2
1
2
2
1
3
3
1
1
1
1
6
6
4
5
7
6
6
7
4
7
4
5
TUclvorcs
1
1
2
2
1
1
2
2
1
2
2
16
15
15
16
22
22
17
16
13
15
13
15
-------
Appendix Table E-8.
Number and relative importance of food web linkages to trophic levels characterizing gravel-cobble
shallow sublittoral habitats of north Fuget Sound and the Strait of Juan de Fuca. (1° • primary,
2° = secondary, 3° '• tertiary, Incid = incidental trophic linkages, Nn - number of food web
nodes indicated on Table E-7.)
CO
O
O
Cherry Point
(Legoe Bay)
Anacortes
(Guemes, S.)
W. Wliidbey I.
Burrows Bay
(Alexander's
Beach)
(West Beach)
San Juan Is.
(Deadman Bay)
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
4 1
4
4
it 1
4 1
5 1
4 1
4
4 1
4 1
4 1
3 1
4
5
4
5
5
4
5
4
4
5
5
4
Fhytorlonkco. H,c,o,l,
1 1
12 12
4 12
12 1
13 1
14 12
3 12
13 1
1 3
13 1
12 1
1 1
1 1
1 1
1
1 1
1 1
1
2 1
2 1
2 1
1
3
2
2
2
1
1
2
3
2
1
1
2
1
2
3
2
2
6
4
7
6
4
7
9
3
5
7
8
7
4
4
4
4
3
5
8
5
8
8
8
7
7
3
6
4
6
6
6 2
61 2
4
5
52 2
52 2
4 1
4 1
4 1
5
4
4 1
5 1
4
4 2 >'• 2
42 2
42 2
52 2
•y
4
4
4
4
4
4
4
<4
4
4
5
5
5
4
4
4
4
4
4
4
4
4
4
4
3 3
5 2
7'5
3 5
7 4
6 5
5 7
3 2
2 4
5 3
10 6
4 4
3
1 1
6 4
2 1
2 2
5 4
4 5
2 1
9 2
9 7
10 5
10 3
3
7
7
3
7
13
6
5
6
15
9
,7
5
7
5
5
8
9
6
10
15
14
9
4
3
7
7
5
6
5
1
6
4
5
3
2
4
1
2
3
7
3
6
15
11
4
2 8
2 9
6 13
4 13
3 13
1 14
7 13
2 13
2 9
2 12
7 19
4 11
1 5
1 7
5 12
2 8
3 8
5 10
4 10
3 7
2 16
5 18
7 19
9 18
5 9 18
2 4 10
8 14 25
8 13 20
7 9 20
8 14 19
9 22 25
2 11 12
6 10 18
6 13 16
10 25 24
7 18 19
3 11 10
1 9 12
4 11 18
1 9 13
3 8 13
5 13 16
7 17 21
2 11 15
4 18 16
10 23 29
7 24 20
5 18 23
Total 1
"l
40
25
60
54
49
55
69
38
43
47
78
55
29
29
45
31
32
44
55
35
54
80
70
64
X No,
llnk.igti
(Nj/Nn)
2.11
1.67
1.76
2.00
1.81
1.77
1.73
1.90
1.95
1.96
1.86
1.96
2.07
1.93
1.67
1.94
1.88
2.00
2.12
1.84
1.80
1.86
1.75
1.94
-------
Appendix Table E-8, cont'd
Ul
O
(South Beach)
Port Angeles
(Dungeness
Spit)
(Morse Creek)
(Kydaka Beach)
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
fir.ncr< gr.ncrs pl.int £
1' 2' 3* Incid 1' 2* 3' Incld 1* 2* 3
4 11
5 31
4 31
4 21
5
4
3
5
6 2
6 1
4
4
4
4
3
3
' Incid I' 2
2
4
2
2
1
1
2
1
1
1
1
• 3'
6
10
8
6
4
2
5
4
5
6
5
4
5
4
3
5
Incid
4
3
3
4
4
3
4
4
4
4
4
4
4
4
4
4
Prim
I 1' 2' 3'
1 2
1 2
1 2
1 1
1
1
1
1 1
1
1
1 1
1
1
1
Incid
4
4
4
4
5
4
4
4
5
4
4
5
4
4
4
4
!• 2'
4 4
7 7
7 2
4 2
1 2
4 3
2 2
1 2
1 4
2 1
2
3
2 1
1,4
1 2
3 1
3* ]
9
19
7
6
3
2
2
5
8
7
9
6
5
3
2
3
Incld !• 2'
7
17
10
7
4
2
2
1
10
8
3
4
2
6
2
2
1 3* Incn
4
6
5
5
2
2
4
5
3
1
5
5
2
3
4
i i'
9
16
15
11
7
8
6
6
10
10
5
5
6
6
5
7
Suf
• 2'
6
11
4
4
3
3
3
2
6
3
3
4
2
4
5
2
itot.i
J' I
15
31
17
14
7
4
7
9
13
13
14
10
10
7
3
8
i
ncld
20
25
23
21
13
11
14
14
22
17
16
18
10
16
13
14
Tot.il 1
llnk.nsoi
"l
50
83
59
50
30
26
30
31
51
43
38
37
28
43
26
31
lln
per
IN1
2.
2.
2.
1.
1.
1.
2.
1.
2.
1.
2.
2.
2.
2.
2.
2.
No.
k.in
-------
Appendix Table E-9.
Distribution and abundance of food web nodes characterizing sand/eelgrass shallow sublittoral
habitats of north Fuget Sound and the Strait of Juan de Fuca.
Herbivores Mixed
Rer.lon (location)
Cherry Point
(Birch Bay)
San Juan Is.
(Eagle Cove)
j5 Strait of Juan
de Fuca
(Beckett Ft.)
(Twin Rivers)
Season
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
urocessor planes feeders
5 2
4
421
431
4 2
4
4 2
3 3
3 1
4
3 2
331
3 1
3 1
4 2
3 2
fcr.i7.crs r.r.izcrs detriti
1 4
1 4
1 2
2
2
3
3
2
2
1 2
2
2
4
4
3
3
is Oinnlv<
4
4
4
4
2
3
4
2
4
3
4
6
3
5
4
4
Pl.-mkLivorcs Benthlvoi
res Plscivorcs
ores carnivores carnivores feeders feeders feeders Carnivores PelaKlc Demersal
5
6
5
3
2
5
7
1
2
7
4
6
6
9
6
5
12
13
13
9
10
10
10
8
10
10
7
11
9
9
9
8
origin fcndlnK nodrri
33
33
32
26
22
25
30
19
22
27
22
32
26
31
28
25
-------
Appendix Table E-10.
U>
O
U>
Number and relative importance of food ueb linkages to trophic levels characterizing sand/eelgrass
shallow sublittoral habitats of north Puget and the Strait of Juan de Fuca. (1° - primary, 2' -
secondary, 3* - tertiary, Incid ™ incidental trophic linkages f Nn « number of food web nodes
Indicated on Table E-9.)
B..CIOII (loc.itlon)
Cherry Point
(Birch Bay)
San Juan Is.
(Eagle Cove)
Strait of
Juan de Fuca
(Beckett Ft.)
(Twin Rivers)
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Bi.ircrs
5
4
4
4
4
4
4
3
3
4
3
3
3
3
4
3
1
1
2
1
1
1
1
2
2
2
3
2
2
3
1
2
3
1
2
6
6
It
4
3
3
3
3
2
2
2
2
4
4
3
3
10
12
8
7
6
9
11
5
10
10
9
14
10
14
13
11
6
6
6
7
6
6
6
6
6
7
7
6
6
7
7
7
2
1 2
1 2
2
2
2
2
2
2
1 2
2
2
2
2
2
2
2 4
2 5
2 4'
2 1
2 1
2 3
2 2
2
2 5
3 5
2 1
2 3
2 5
2 6
2 4
2 2
4
4
4
3
3
4
7
3
1
5
1
4
4
7
5
6
16
16
19
15
15
13
16
11
12
11
17
17
12
12
13
11
11
11
8
4
9
12
11
2
9
10
5
11
10
10
9
5
12
11
13
9
7
7
8
6
9
10
6
10
9
10
10
5
10
10
8
7
6
7
10
6
3
8
3
6
8
11
8
9
28
30
29
24
23
24
29
18
24
23
28
33
24
28
28
24
19
19
16
13
17
20
19
10
17
20
14
19
18
19
18
14
Tot.il 1
"l
69
70
66
53
53
58
66
46
53
71
51
68
59
67
64
52
K NO.
lui.ir,"
(Nj/Nn)
2.09
2.12
2.06
2.04
2.41
2.32
2.20
2.42
2.41
2.63
2.32
2.13
2.27
2.16
2.29
2.08
-------
Appendix Table E-ll.
Distribution and abundance of food web nodes characterizing mud/eelgrass
shallow subllttoral habitats of north Puget Sound and the Strait of Juan de Fuca.
O
•C-
Herbivore* Mixed
Rrelon {locution)
Anacortes
(Fidalgo Bay)
San Juan Is.
(Westcott Bay)
Port Angeles
(Jamestown-
Graysmarsh)
Season processor
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
Spring
Summer
Autumn
Winter
4
4
It
4
4
4
4
4
5
2
3
3
plants
2
2
4
1
3
2
4
feeders
1
1
2
2
1
3
3
2
1
2
1
1
Erasers ernzcrs detritus Omnlvores
1 1
1 1
1 1
112
3
2
1 1
1
112
1
2
1
5
6,
8
5
5
8
8
3
3
4
6
4
rlanktivores Bcnthivorcs Plsclvores
carnivores carnivores feeders feeders feeders Carnivores Pelaelc Demersal origin
8
5
3
4
9
10
9
6
6
4
5
2
5
8
11
9
8
1 11
1 10
6
1 16
5
6
6
4
1
1
1
1
1
1
1
1
1
1
1
feeding. nodcH
31
27
33
33
31
40
38
24
40
19
26
22
-------
Appendix Table E-12.
Number and relative Importance of food web linkages to trophic levels characterizing mud/eelgrass shallow
•ubllttoral habitats of north Puget Sound and the Strait of Juan de Fuca. (1* - primary, 2* - secondary,
3* - tertiary, Incld - Incidental trophic linkages, Nn - number of food web nodes Indicated on Table E-ll.)
teflon (location)
Anacortes
San Juan Is.
Port Angeles
(Jamestown-
Graysmarsh)
Fhytoplankton Nacronli;**
Spring
Autumn
Spring
Autumn
Winter
Spring
Summer
Autumn
Winter
4
4
4
4
4
5
2
3
3
2
3
1
3
2
2
2
1
1
2 26
2
1
1
4
2
4
2 21
4 12
2 21
1 9
2 10
1 11
2 18
1 11
4
4
5
5
4
6
4
4
4
1 2
1 2
2 2
2 2
2 2
2 2
2
1 2
2
lucid
2
2
2
2
2
2
2
2
2
6 3
13
2 6
1 7
5
5 4
2 4
1 5
3
8 18
9
8
12
4
6
5
4
7
9
12
22
8
31
2
8
4
2 2 14 6 18 26
2 2 10 6 34 17
2 1 7 12 24 20
2 1 9 11 37 31
2 1 7 8 17 15
2 2 16 8 20 41
2 1 6 5 20 9
2 1 7 8 26 15
2 8 4 22 10
Total (
"l
64
67
63
87
47
85
40
62
44
• No.
llnk«|*«
(Mj/Hn)
2.06
2.03
2.03
2.29
1.96
2.13
2.11
2.38
2.00
-------
APPENDIX F
MECHANISMS OF PETROLEUM HYDROCARBON INFLUENCE UPON FOOD WEB STRUCTURE
F-l. Effects Upon and Within Marine Organisms
The literature describing the biological effects of petroleum
hydrocarbons on marine organisms is extensive. Recent symposia and
syntheses have summarized the state of the knowledge (Baker 1978; Am. Inst.
Biol. Sci. 1976; Wolfe 1977; Malins 1977; Mclntyre and Whittle 1977; Fish.
Res. Board Can. 1978) and the reader is referred to these for a thorough
discussion of petroleum in marine ecosystems. Documentation of the acutely
toxic levels and fractions of petroleum hydrocarbons has provided accurate
indications of short-term effects on marine biota (Craddock 1977). In the
long run, however, sublethal or chronic effects may be more important to
food web structures than acute effects, in that subtle changes in behavior,
growth, natural mortality, reproduction, and general physiological condition
may alter or eliminate critical predator-prey linkages (Blumer 1970; Sprague
1971; Tarzwell 1971). A brief introduction to biological fate and
effects in selected marine organisms is necessary for our understanding of
the potential incorporation and transfer of petroleum hydrocarbons in food
webs of north Puget Sound and the Strait of Juan de Fuca.
F-l-a. Toxic Components
Of the two basic categories of the water-soluble fractions of petrol-
eum oils, the volatile and the non-volatile, the volatile components have
generally been shown the more toxic, and thus have received the most
attention (Moore and Dwyer 1974; Donahue, et al., 1977; Lee, et al., 1973:
Struhsaker 1977; Morrow, et al., 1975). Although more persistent and more
likely to enter the food web, non-volatile aromatics and their biological
effects have not been as well studied (Emery 1970; Winters, et al., 1976).
For example, Lee and Nicol (1978) pointed out that although the volatile
aromatics were measurably more toxic to the marine amphipod Elasmopus
pectenicrus, the concentrations which induced acute mortality were higher
than would naturally occur in the water-soluble fraction. The non-volatile
aromatics, although much less toxic, had a greater potential of biological
interaction with the marine organism because of their persistence at high
concentrations in the environment.
F-1-b. Uptake, Retention, and Depuration
Uptake and retention of petroleum hydrocarbons appear to vary accord-
ing to the type as well as the form of hydrocarbon. In general, aromatic
hydrocarbons of high molecular weight will be retained in an organism's
tissues longer than hydrocarbons of low molecular weight, total release
of hydrocarbons requiring from 2 to 60 days (Neff, et al., 1976).
Concentrations of aromatics in tissues are assumed to reach an equilibrium
with external concentrations, and hydrocarbons of lighter molecular weight
tend to reach this equilibrium at a faster rate than heavier compounds.
Retention of petroleum hydrocarbons in animal tissues appears to be a
306
-------
passive process, primarily through the partitioning of the hydrocarbons
between the water and tissue lipids (Neely, et al., 1974; Neff, et al.,
1976). Active biological processes such as ventilation, blood circulation,
excretion, and hydrocarbon metabolism determine the actual uptake and
release.
According to Stone (1975) and Neff, et al. (1976). the incorporation
of hydrocarbons with tissue lipids is probably by hydrophobic interaction,
which means that the hydrocarbons remain in an exchangeable form. Exposure
to petroleum hydrocarbons for a long period of time, however, allows a
small fraction to enter a stable state in the tissue from which it is not
readily exchangeable (Stegeman and Teal 1973; DiSalvo, et al., 1975; Neff,
et al., 1976). When the organism is eventually re-exposed to hydrocarbon-
free water, hydrocarbon is released from this stable fraction more slowly
than hydrocarbon is bound by hydrophobic reaction.
Experiments on the uptake and fate of petroleum hydrocarbons (radio-
labelled paraffinic and aromatic hydrocarbons) by the blue crab Callinectes
sapidus indicated that up to 10% of the hydrocarbons can be taken up from
either water or food organisms (Lee, et al., 1976). All the assimilated
hydrocarbons were metabolized or eliminated through fecal matter. More
than half of the metabolic activity involving the labelled hydrocarbons
occurred in the hepatopancreas, which was the only site of radioactivity
25 days after exposure. In fish, however, the liver and gall bladder
appear to be the primary organs involved in the metabolism of hydrocarbons
ingested or assimilated (Lee, et al., 1972).
Both feeding mode and intrinsic capabilities appear to determine the
extent of hydrocarbon uptake by benthic invertebrates. Roesijadi, et al.
(1978), conducted experiments with deposit-feeding bivalves (Macoma
inquinata) and sipunculids (Phascolosoma agassizi) and suspension-feeding
bivalves (Protothaca staminea) exposed to aliphatic and diaromatic
hydrocarbons. In general the deposit feeders accumulated the hydrocarbons
to a greater extent than did the suspension feeders. Roesijadi, et al.
(1978), also indicated that compounds of higher molecular weight will be
relatively persistent in the tissue of exposed bivalves.
Even though depuration or release of assimilated petroleum is usually
rapid, it is most often incomplete. Small quantities of hydrocarbons are
often retained long enough to be transferred to a higher trophic level.
Lee (1975) found that detectable residues of labelled benzo(a)pyrene were
evident in Calanus helgolandicus after 9 days, in £. plumchrus after
16 days, and in C^. hyperboreus after 4 weeks. Molluscs appear to be unable
to metabolize hydrocarbons (Lee, et al., 1972; Carlson 1972) but able to
eliminate accumulated hydrocarbons by depuration (Lee, et al., 1972;
Stegeman and Teal 1973; Neff and Anderson 1975).
F-l-c. Detection and Avoidance
Many references suggest that fish have the ability to avoid petroleum
hydrocarbon-saturated waters (Boesch, et al., 1974; North, et al., 1965),
especially offshore waters. The ability of many fish to detect petroleum
hydrocarbons at low levels has been illustrated in several cases but there
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are a number of contradicting reports (Patten 1977). Syazuki (1964) showed
that goby (Chaenogobius heptacanthus), crescent perch (Therapon jarbua),
and striped mullet (Mugil cephalus) exhibited threshold responses at
between 0.7 ppm for crude oil and 48 ppm for "Mobil" oil. Larvae of
Atlantic cod (Gadus morhua), Atlantic herring (Clupea harengus harengus).
and plaice (Pleuronectes platessa), however, showed no ability to avoid
water contaminated by three different types of crude oil (Kuhnhold 1970).
Rice (1973) showed that the ability of juvenile pink salmon (Oncorhynchus
gorbuscha) to avoid water-soluble fractions of Prudhoe Bay crude oil in
a flowthrough system varied according to the fishes' adaptation to sea
water, their age, and possibly the water temperature; in sea water the
avoidance level ranged from 1.6 ppm to 16.0 ppm.
F-2. Indirect Sublethal Effects
F-2-a. Effects on Reproduction, Growth, and Metabolism
Incorporation of sublethal levels of hydrocarbons into tissues has
also been shown to alter reproductive success of crustacean populations
by decreasing egg production, increasing mortality rates for egg and
larval stages, and altering basic metabolic processes (Johnson 1977).
Donahue, et al. (1977), examined the physiological response of mud
crab (Rhithropanopeus harrisi) larvae continuously exposed to naphthalene
or phenanthrene under different regimes of temperature and salinity and
found decreased survival to metamorphosis, increased duration of larval
development, increased respiratory rates, and increased sensitivity to
acute salinity stress. They concluded that sublethal hydrocarbon stress
acted to divert assimilated energy from growth to maintenance processes.
Water-soluble fractions of No. 2 fuel oil were lethal to the amphipod
Elasmopus pectenicrus at 4 ppm for short exposure periods, but growth and
fecundity were inhibited at lower concentrations of 0.6 and 0.2 ppm,
respectively (Lee, et al., 1977). When adult isopods (Sphaeroma quadri-
dentatum) were exposed to low levels of oil for one month, the juvenile
stages suffered significantly higher mortalities, more than 70% in five
weeks (Lee and Nicol 1977). In oil concentrations of 0.3 to 0.4 ppm, the
amphipod Gammarus oceanicus produced significantly fewer larvae than the
controls in experiments conducted by Linden (1976). Ustach (1977) found
that the soluble fraction from 200 ul crude oil per liter sea water
significantly reduced egg production by ^he harpacticoid copepod Nitocra
affinis, as well as one-half and one-fourth dilutions; the mean length of
life and the mean number of broods were not significantly affected.
Decreasing fecundity and rate of egg laying have also been shown to
result in birds which had consumed petroleum (Hartung 1963; Grau, et al.,
1977); this may be a function of both direct deposition in the ovary by
transport through the intestinal tract and liver and by changes in the ion
composition of the yolk as a result of osmoregulatory inhibition (Crocker,
et al., 1974, 1975; Grau, et al., 1977).
Oritsland (1975) found that fresh Norman Wells crude oil did not
significantly change the insulating values of ringed seal fur in air and
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at varying wind speeds. It was suggested, however, that the solar heating
of the seal's skin during haulout would be increased.
Enzymatic and histological evidence of kidney damage, possibly due to
an unsuccessful attempt to concentrate or excrete the oil or its metabolites
through the urinary system, was evidenced in Smith and Geraci's (1975) oil
immersion studies with ringed seals, Phoca hispida. They suggested that
25 ml to 75 ml ingested crude oil would probably represent the upper
limit of what an animal might ingest without irreversible damage. Thus,
ingestion of oil by immersed seals may not be significant except through
the consumption of live contaminated prey. However, an accumulation of
over 75 ml of petroleum hydrocarbons by this route of entry would require
significant levels of the toxicant in the prey.
Geraci and Smith (1977) suggested that more important consequences
of an oil pollution incident may be eye damage, prolonged moulting, and
the influence of oil on stress of the pinnipeds, rather than accumulation
of petroleum hydrocarbons in tissues. Starvation would probably result.
Pollution incidents would tend to be more detrimental to older seals and
seals in poor nutritional condition.
F-2-b. Tainting of Tissue by Accumulated Petroleum Hydrocarbons
Long-term incorporation of hydrocarbons by predators also has the
potential to limit their utilization as food by man. Even though most
marine organisms are capable of eventually depurating or metabolizing
assimilated hydrocarbons, those of commercial value which may smell and
taste in a manner reminiscent of petroleum, will be unmarketable for a
long time (Blumer, et al., 1970; Bourcat and Mallet 1965; Cahnmann and
Kuratsune 1957; Mackie, et al., 1972; Nitta, et al., 1965; Shipton, et al.,
1970; Vale, et al., 1970).
F-3. Uptake and Effects of Petroleum Hydrocarbons Transferred Via Food
Web Linkages
F-3-a. Food Web Biomagnification
While there has been much discussion of the potential for biomagnif-
ication of petroleum hydrocarbons with transfer through the food web, no
definitive studies have illustrated such a phenomenon. In fact, although
most marine organisms are capable of accumulating high concentrations
(200-300 times in crustaceans and fish) directly from sea water, there is
no evidence that petroleum burdens in tissues actually increase at higher
trophic levels (Varanasi and Malins 1977).
F-3-b. Transmittal via Food Web Linkages
Trophic transfer, i.e., from prey to predator, of petroleum is well
documented, however, and there is good evidence of sublethal effects
resulting from the incorporation or metabolism of the hydrocarbons by the
consumer.
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Corner, et al. (1976), found that at least for zooplankton, uptake
of hydrocarbons via food particles was a more significant and longer-lasting
route than via direct uptake from the water solution. Not only was the
total accumulation of hydrocarbons (naphthalene) higher from the food web
transfer but depuration was considerably slower such that a third of the
radiolabelled hydrocarbons remained in calanoid copepods ten days after
exposure to contaminated food particles. Conover (1971) found that
copepods (Temora longicornis, Calanus finmarchicus) ingested suspended
bunker C oil particles from the ARROW spill in Chedabucto Bay and accounted
for up to 10% of the oil in the water column. Ingestion of the oil had no
apparent effect on the copepods, as they passed it with their feces which
were shown to contain up to 7% oil. This mechanism was considered to be
one of the most important pathways of the pollutant between the pelagic and
the benthic systems—as much as 20% of the total suspended particulate oil
was estimated to precipitate to the bottom as zooplankton feces. Parker,
et al. (1971), calculated that the calanoid copepod Calanus finmarchicus
could graze up to 1.5 x W~^ g of oil per day. Thus, assuming a density
of 2,000 per m3 over a 1-km2 area to 10 m depth, as much as three tons of
oil could be encapsulated and precipitated as feces per day!
Such high rates of uptake illustrate the rapidity with which
suspended petroleum can be biologically converted into a form available
for ingestion by higher trophic level organisms, through ingestion of
either the contaminated copepods by pelagic carnivores or of their feces
by benthic detritivores.
The predators of the hydrocarbon-burdened zooplankton, unlike the
zooplankton, will often incorporate the hydrocarbon into their tissues
rather than excrete it. Post yolk-sac larvae of Pacific herring (Clupea
harengus pallasi) that were fed rotifers (Brachionus plicatilis) contain-
ing high accumulated levels of labelled benzene rapidly incorporated the
monoaromatic hydrocarbon into their tissues (Struhsaker 1977). Assimila-
tion of the hydrocarbons or metabolism products usually takes place in
high-lipid tissues, especially the reproductive organs. In this case,
effects upon the organism's reproductive efficiency result. Struhsaker's
(1977) exposure of female Pacific herring to the aromatic hydrocarbon
benzene caused a pronounced reduction in survival of the ovarian eggs and
resultant embryos and larvae through yolk absorption; the later life
history stages suffered the highest mortality, 43%. Again, the total
effect of incorporation of the hydrocarbons into the food web would not be
manifested until the next generation of the carnivore populations, which
in some cases might not occur for two to three years.
Ogata, et al. (1977), documented the accumulation of paraffins,
organic sulfur compounds, and aromatic hydrocarbons by eels reared in a
crude oil suspension. Paraffinic hydrocarbons were detected in salmon
(Oncorhynchus keta), mullet (Mugil cephalus), and black sea bream (Mylio
macrocephalus) collected from waters polluted by a crude oil spill outside
Niigata Harbor in the Sea of Japan (Motohiro and Inoue 1973). Indications
of higher n-paraffin concentrations in the digestive organs suggested that
the hydrocarbon contamination in this case was acquired principally through
feeding. Brown trout (Salmo trutta) collected 11 days after a diesel fuel
spill were found to still contain n-paraffin (C-IO~CIQ) hydrocarbon compounds
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(Mackie, et al., 1972). These results showed that many of the aliphatic
saturated hydrocarbons and possibly some of the aromatics characteristic
of the spilled diesel oil were also present in the flesh of the trout.
F-4. Ecological Effects of Petroleum Hydrocarbons
F-4-a. Vulnerability of Lower Trophic Levels
Studies of the toxicity of petroleum hydrocarbon components to marine
biota indicate that in general the lower the trophic level, the more
sensitive the organism. For example, marine crustaceans are more vulnerable
to petroleum hydrocarbons than are marine fish and marine mammals. This
suggests that although the organisms at the upper end of the food web,
which are most often utilized by man, have greater tolerance of the effects
of petroleum hydrocarbons in the marine environment, the productivity and
stability of lower trophic levels can be altered to the point where basic
food limitations can be effected upon the higher consumers. This process
is potentially one of the longest lasting and most deleterious effects of
petroleum pollution, and it has to be the most difficult to detect,
considering the present knowledge of food web dynamics and natural
variability in food resources and the consequential effects on the
consumers.
F-4-b. Disruption of Autotrophic Production
It is not unreasonable to assume that some effects are going to be
manifested at the very base of the trophic pyramid, the photosynthetic
generation of carbon by phytoplankton. The presence of oil, undergoing
the processes of weathering and degrading on the surface film, can
radically alter the utilization of organic and inorganic nutrients
(nitrogen, phosphorus) by the primary producers (Williams 1967; Feldman
1973). No. 2 and No. 3 fuel oils and Venezuelan crude oil generally
inhibited phytoplankton growth at concentrations greater than 30-50 pg/1
in radiocarbon-uptake experiments by Gordon and Prouse (1973). Stimulation
of photosynthesis as reported by Mironov and Lanskaya (1969) and Strand,
et al. (1971), was apparent only for low concentrations of the crude oil
during spring. (Gordon and Prouse indicated that the highest oil
concentration they had ever measured in sea water, 25 cm below a 2-day
crude oil slick, was 800 ug/1.)
F-4-c. Effects on Herbivores
The existence of water-soluble petroleum hydrocarbons in the water
column can also affect the ability of suspension-feeding herbivores to
utilize phytoplankton. One effect is through behavioral inhibition of
the herbivores' feeding process. A decrease in copepod filtering rate
was surmised from a decrease in fecal pellet production by copepods
exposed to an oil droplet concentration of 10 pom for 20 hours (Spooner
and Corkett 1974).
Reduction of food resources of zooplankton has the effect of reducing
overall production by influencing both the occurrence of adults and their
sex ratio (Conover 1965; Omori 1970). Even subtle alterations in the
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community structure of the primary producers available as food for the
zooplankton have the potential to inhibit growth and reproduction. This
is a prominent process in natural systems which has been evolutionarily
accommodated by the various life history strategies exhibited by the
zooplankton. The question arises, however, of the effects of changes in
the available phytoplankton beyond magnitudes and time frames to which
the zooplankton have adapted.
Parsons, et al. (1967), provided evidence that although zooplankton
may consume a variety of foods, only a few food items may provide a
satisfactory diet for growth and reproduction. Specifically, they found
that the diatoms Chaetoceros debilis and C\ socialis were poor food sources
for three zooplankton organisms in the Strait of Georgia. Consequently.
the growth rate of late stage Calanus plumchrus populations (an important
prey of juvenile salmon) under the Fraser River plume, declined when the
only food supply available consisted of small flagellates in late April
(Parsons, et al., 1969).
F-4-d. Disruption of Heterotrophic Production
In the nearshore ecosystem, where the decomposition of detritus by
marine microflora is an important process in the annual production of
food resources available for epibenthic zooplankton and benthic meiofauna,
petroleum hydrocarbons could influence the rates or timing of this
conditioning process. There is little evidence to indicate that bacteria
would be negatively affected by the introduction of petroleum. Hodson,
et al. (1977), reported that although bacteria were the first organisms
in the CEPEX enclosures to be affected by introduced oil, their rapid
generation time, the diversity of strains, and their ability to mutate
allowed a rapid recovery of heterotrophic activity. There is some question,
however, of the possible effects of hydrocarbons on the behavior of the
bacteria. Walsh and Mitchell (1973) have indicated that the chemotaxic
behavior of the bacteria—i.e., the ability to detect and move to food
sources—was significantly inhibited by various petroleum products and
components. Such an effect, though seemingly critical, may be completely
compensated for by the increased growth of sulfide-generating bacteria in
response to the petroleum hydrocarbons as suitable organic matter (Colwell
and Walker 1977; Karrick 1977). Westlake, et al. (1J78), have illustrated
that such microbial populations exist to some degree at 22 sites in north
Puget Sound and along the Strait of Juan de Fuca and would logically be
capable of expanding and utilizing petroleum spilled in the region. It
remains to be verified, however, whether these oil-degrading bacteria
would naturally utilize these detrital sources or would be acceptable to
bacteria-stripping zooplankton and meiofauna.
F-4-e. Alteration of Food Resources of Consumer Organisms
The effect of food limitation upon consumers such as planktivorous
fish may be even more pronounced than for zooplankton as the potential for
adaptation and capability for rapid population responses tend to be more
limited. For instance, the abundance and size composition of zooplankton
has been suggested as critical determinants of fish survival during the
transition from larval to juvenile stages (Thayer, et al., 1974). The
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early life histories of many economically and ecologically important fish
species of the region (Pacific salmon, herring, sand lance, greenling,
and smelt) include larval and juvenile stages which reside in the region's
surface waters for weeks or months. At this time, their growth and
ultimately their survival are in part dependent upon their achieving
an adequate ration of prey organisms.
Blaxter (1965) provides evidence from Soviet investigations that
reasonable survival of fish larvae requires concentrations of prey
around 20,000 per m3 and that lower survival rates would be suspected at
prey concentrations less than 5,500 per m3- LeBrasseur, et al. (1969),
calculated that the waters of the Fraser River plume in the southern
Strait of Georgia possessed approximately 10,000 copepods (assuming all
Microcalanus sp.) per m3 in early March when considerable numbers of
larval fish are in the area. Plankton sampling in the Strait of Juan de
Fuca (Chester, et al., 1977) suggests significantly lower abundance in
that region, but they sampled no stations in the nearshore environs where
zooplankton populations may be larger.
Just as important as total abundance, the size composition of the
zooplankton also determines the extent of exploitation by piscivorous
fish. LeBrasseur, et al. (1969), illustrated that larval fish occupying
the region of the Fraser River plume in the Strait of Georgia grazed
mainly on zooplankton in the 500-y size range while juvenile fish utilized
700-y to 2,000-y plankters. This is not a static pattern but changes with
the changes in morphology and bioenergetic demands and feeding capabilities
which occur as the fish grow. For instance, Pacific sand lance (Ammodytes
hexapterus) less than 20 mm in length feed specifically on zooplankton
(nauplii and copepod eggs) less than 500 y, while Pacific sand lance
greater than 40 mm prey on zooplankton in the 500-y to 1,000-p range
(LeBrasseur, et al., 1969).
These findings imply that since only a small portion of the available
prey resource is usually exploited by predators at a particular time, any
deleterious influence on this fraction, despite the maintenance of the
unexploited fraction, may actually limit the production of the predator
population. The principal example in the case of the neritic food webs
of north Puget Sound and the Strait of Juan de Fuca is the surface layer
zooplankton community which is made up primarily of small calanoid
copepods (Pseudocalanus sp. and Microcalanus sp.). It is this community
which is heavily utilized by larval and juvenile fish during late winter
and spring and which would appear to be the most susceptible to water-borne
petroleum hydrocarbons. Deepwater zooplankton, composed primarily of
large calanoids, Calanus sp., would be less affected, and through diel
vertical migrations such zooplankton would still be available to the fish.
This implies, however, the necessity of the fish to switch from one prey
resource, which appears to provide an optimal opportunity to gain an
adequate daily ration, to one which may not be adequate. Although prey
switching may be feasible (Murdoch, et al. , 1975; Oaten and Murdoch 1975;
Reed 1969) because of the availability of sufficient numbers of alternative
prey and plastic feeding behavior of the predator, the alternative prey
resources may not be optimal from the standpoint of their size, avoidance
capabilities, or nutritional value. The inability to secure an adequate
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ration usually results in a sacrifice in growth, reproduction, or ultimately
survival.
In the example just cited, the small calanoid copepods Microcalanus
sp. and Pseudocalanus sp. appear to be unsuitable as a sustained food
source for juvenile salmon (pink and chum) because of their size and
behavior, whereas the larger copepods such as Calanus sp. can provide
adequate rations at lower concentrations (LeBrasseur, et al., 1969).
Koeller and Parsons' (1977) studies of juvenile chum salmon
(Oncorhynchus keta) also illustrated that the young salmon had greater
difficulty obtaining their required ration from small copepods (0.07-
0.12 mg—such as Pseudocalanus minutus, Paracalanus parvus, Corycaeus
anglicus) than from large copepods (0.4-2.0 mg—such as Calanus plumchrus,
Centropages abdominalis), even though the smaller prey were ten times
more numerous than the larger. Apparently, energy acquired from feeding
on the more numerous smaller copepods was utilized for the extensive
feeding activity and basic metabolism, whereas energy obtained from eating
a few large copepods allowed energy in excess of basic metabolism and
feeding activity to be diverted into growth. Thus, alteration of the
available prey community by a pollutant introduction may have a more
critical effect than the direct effect upon the predator, especially in
the long run.
More important than basic somatic growth, reproduction in fishes is
highly dependent on food supply. Although there is some variability in
the species' strategies under the stress of inadequate ration, most
investigators have found reproduction parameters—numbers of spawnings,
percentage of population reproducing, total egg production, percentage of
ovarian oocytes with yolk, post-spawning survival—are directly correlated
with ration level (Bagenal 1969; Scott 1962; Tyler and Dunn 1976; Wootton
1977). Thus, if a pollutant alters the food supply of a significant
portion of the reproductive population in one year, the production of
that year class will be affected for several years thereafter.
F-4-f. Effects of Removal or Reduction of Keystone Species
While disruption of the food web structure by impacts at the lower
trophic levels is likely, just as likely is disruption of the community
structure by selective mortality or severe sublethal effects on keystone
species at higher trophic levels. Seastars (Pisaster sp, Leptasterias sp.),
sea urchins (Strongylocentrotus sp.), predatory gastropods (Thais sp.),
and large infaunal bivalves (Tapes sp., Mya sp.) typically have very low
recruitment ratess and so removal or dramatic reduction of these species
would probably result in a sustained modification of the nearshore
community structure for years or decades. Such community disruption has
the potential to dramatically affect production of macrophytic algae, a
major component of the detritus-based food webs.
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321
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APPENDIX G
BIOENERGETIC MODEL OF THE EPIBENTHIC FOOD WEB IN THE MUD/EELGRASS SHALLOW
SUBLITTORAL HABITAT AT WESTCOTT BAY
A simplified bioenergetic model was constructed for one nearshore
site in northern Puget Sound for which we had the most reliable quantita-
tive data—the relatively enclosed, mud/eelgrass embayment habitat at
Westcott Bay on the northwestern coast of San Juan Island. The epi-
benthic food web was emphasized because we had community and trophic data
on the epibenthic and demersal fish and invertebrate communities (Miller,
et al., 1977; Nyblade 1978) and fairly meager, unquantitative data on
food webs of infauna communities. We recognize that such an approach has
little applicability to the Westcott Bay system as a whole, and much less
to other mud/eelgrass, contained embayment habitats in north Puget Sound.
Food web data have been summarized in a very simplified diagram
(Appendix Fig. G-l) where population abundance (mean + 1 s.d.), biomass
(mean + 1 s.d.), and frequency of occurrence over time have been estimated
for the nodes of the web. Transfer rates between nodes include the number
of prey consumed (mean + 1 s.d.), the biomass consumed (mean + 1 s.d.),
and the frequency of consumption. In addition, growth rates were
estimated for secondary consumers in order to calculate node production.
Primary Production
Many herbivores are present in tropical marine waters but not in
temperate-water habitats such as Westcott Bay. In a Nova Scotian kelp
community, Mann (1973) found that herbivores consume less than 10% of the
primary production and 90% entered detritus food chains. Thayer, et al.
(1975), found detritus deposition rates in eelgrass beds to be 12-22 mm
per year and this was either utilized as food in the system or exported.
Harrison and Mann (1975) showed that eelgrass detritus provides a better
food source than dead intact leaves because there is a rise in the
percentage of nitrogen during bacterial decomposition. The assimilation
efficiency of detritus by macrofauna in eelgrass beds has been estimated
at 46%-48% (Adams and Angelovic 1970). As has been shown in this report,
it is evident that detritus input from eelgrass and macroalgae forms the
base of the nearshore food webs in coastal marine ecosystems. The
relative importance of pelagic primary production has not been accurately
assessed in nearshore ecosystems, however.
Standing stock and production of macroalgae and rooted vegetation
have been estimated in many areas (Appendix Table G-l). Four categories
of primary energy sources were identified in Westcott Bay: Plankton,
rooted macrophytes (eelgrass), epiphytic and epibenthic algae, and
macroalgae. McRoy (1977) estimates that epiphyte dry weight equals that
of leaf dry weight in eelgrass beds. Based on literature estimates,
standing crop and production were estimated for the primary energy sources
in Westcott Bay (Appendix Table G-2). The production of epiphytic algae,
a principal energy source for grazers, was estimated with less confidence.
322
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Staghorn sculpin
.2 1
t gio.O
33
Phytoplankton
Starry flounder
4.715.2.
2>7.0t 49.
English sole
Polychaete
Snake prickleback
40.2. t- es.(<,
142.S tZ3t>.
Shiner perch
Penpoint gunnel
Surf smelt
Appendix Fig. G-l.
Westcott Bay.
Bioenergetic food web model of epibenthic community of
Fish population and consumption data were obtained in
a 900-m2 sampling area. Node and linkage values are, from top to
bottom, number m"1, grams m"1, and % frequency of occurrence.
323
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Appendix Table G-l. Standing stock and primary production in coastal
detritus-based system. Numbers have been converted to g/m2 wet
weight.
System Standing stock Production
Eelgrass, Alaska „ „
(McRoy 1970) 585-13,590 g/m 243 g/m /day
Eelgrass, Denmark
August 3,987 g/m 9,900 g/m /yr
(Sand-Jensen 1975)
Brown algae, Nova Scotia
(Mann 1973) 2,001 g/m 13,000 g/m /yr
Eelgrass, North Carolina
Detritus 46,000 g/m 2
Primary production 3,400 g/m /yr
(Thayer, et al., 1975)
Eelgrass, Scotland
Plankton 2,085 g/m2/yr
Substrate-primary production 88-197 g/m2/yr
(Mclntyre and Eleftheriou 1968)
324
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Appendix Table G-2. Estimated primary energy sources (wet weights)
in Westcott Bay, San Juan Island. Values are
annual means.
Standing crop Annual production
2 2
Source g/m g/m
Phytoplankton 14 560
Rooted macrophytes 2,500 1,740-9,900
Epiphytic and
epibenthic algae 2,000 20,000
Macroalgae 200 2,000
325
-------
Each of these four primary production compartments contributes energy
to grazers, detritus, and dissolved organic matter. These flows were
estimated for Westcott Bay as contributions to annual production (Appendix
Fig. G-2). In the absence of any quantitative data the detritus in
eelgrass beds was considered simply as steady state with no net erosion
or accumulation necessary to maintain the bed. This provides a first-
order estimate of detritus available to fish predators through
detritivorous prey, but may grossly underestimate the total amount of
organic carbon (such as dissolved organic carbon) which is contributed
to the food web by eelgrass.
Primary Consumers
The primary consumers form the important energy link between primary
production and higher trophic level carnivores. Brook (1977) in a
Florida eelgrass bed found that polychaete and epibenthic crustacean
populations limit the fish predator population. Most high trophic level
carnivores in eelgrass beds are at least partly benthic predators.
Mclntyre and Eleftheriou (1968) estimated the benthic meiofauna standing
crop in a flatfish nursery to be 1.25 g C m~2 dry weight and the annual
production was approximately twice the standing crop.
The primary consumer level may be divided into two classes based on
feeding mode—suspension feeders and deposit feeders. A loss of organic
matter to the system at this level may be caused by maintenance,
inefficient ingestion processes, production of pelagic gametes, and
conversion of organic matter into unusable elements (Levington 1972).
Selectivity in feeding by size and energy content of particles was shown
for a deposit-feeding bivalve (Hylleberg and Gallucci 1975). Brinkhurst,
et al. (1972), found the same two criteria in particle selection for a
tube-building oligochaete and they estimated respiration and growth to
be 84.5 kcal/g annually.
Feller (1977) estimated production and standing crop of benthic
harpacticoid copepods to be 1 g C m~2 yr"1 and 106 m~2, respectively.
The standing crop estimate is a summer maximum and it is much lower in
the winter. Cohorts took six months to mature and the instantaneous
daily population increase was -0.3 to 2.2.
Dagg (1975) estimated carbon and nitrogen budgets for an amphipod
which feeds on both diatoms and copepods. The younger individuals are
primary consumers and they switch to a more carnivorous diet with age.
The assimilation efficiencies of both carbon and nitrogen ingestion were
90%. Dagg found this higher than assimilation efficiencies for other
carnivorous aquatic invertebrates: Polychaetes, 82-89%, euphausiids, 84%.
Ingestion rates increased when the amphipod switched from diatoms to
copepods. The daily ingestion rates on diatoms were 4-60 g C and 0.7-12
g N and copepod ingestion rates were 120-1,000 g C and 40-190 g N.
Population information for the primary consumers in Westcott Bay
was derived from subtidal core samples and epibenthic pumping.
326
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Primary
Producers
planktoji t-
560 g/irr/yr j\
8c/
,0
UOM
\
75";
8%
I
rooted I
macrophyles j
(6000)g/m?/yrj
DOM
epiphytic and j
epibenthic .'
macro
2000
DOM
2',
ft irnry
f.onv.nw-rr
(inv,rt-)
/\
ro,,-.,
7000 n/n.' ,/yr
\
^ detritus
..
•1
.•^^
.) ' V •
Appendix Fig. G-2. Estimated flows to detritus, grazed and dissolved
organic matter (DOM) compartments from primary production
compartments.
327
-------
Secondary Consumers
More detailed information is available for population at the
secondary consumer level than at any other. Beach seine and stomach
analysis data from Westcott Bay were collected from July 1974 to
September 1975 (Miller, et al., 1976). Seasonal growth rates and
conversion efficiencies are estimated for the dominant species, staghorn
sculpin and juvenile flatfish (Appendix Table G-3). The growth rate
varies from 0.01 to 0.86 g day"1 and the maximum is in juvenile flatfish
in early summer decreasing as they grow during the summer. Based on a
200-day growing season and growth rate of 0.08 g day"1, the annual
production of secondary consumers in Westcott Bay was estimated
(Appendix Table G-4).
Estimate of Daily Rations of Fishes
Detailed stomach content analysis was available for most secondary
consumer species but the number of stomachfuls ingested per day was
unknown. Some demersal and schooling neritic fish are believed to
forage at dawn and dusk (Hobson 1975; Cooney 1967). If the stomach is
filled during each of these activity periods, then an ingestion rate
may be calculated based on two stomachfuls per day, although as we shall
see this may be an underestimate. This assumption has been used for
estimating ingestion rates in this study.
Three modes of feeding are exhibited by the secondary consumers in
Westcott Bay. The first group are the pelagic feeders, composed of
Pacific herring and Pacific sand lance. This feeding is driven by
neritic production. This group is very abundant numerically and is
subject to heavy predation by birds and larger fish. The second group,
to which perch belong, are epifaunal feeders. This feeding mode is
driven by eelgrass production with a time lag for settlement and growth
of epifauna. Bottom feeders are the third and largest category,
comprising starry flounder, English sole, gunnel, prickleback, and surf
smelt. The top predator, staghorn sculpin, switches opportunistically
between benthic feeding and feeding on pelagic fish.
Seasonal variability in growth rate and conversion efficiency is
quite high. As may be expected in a nursery area, seasonal changes in
biomass are also high at this trophic level. Monthly estimates of
secondary consumer standing crop for Westcott Bay are shown in Appendix
Table G-5. From core samples and stomach analysis, there is also
evidence for seasonal switching of prey by English sole which follows
changing prey availability (Thornburgh 1978), although high variability
may obscure the trends. The same predator's diet changes significantly
between the two sites. With this very high seasonal variability in
growth rate, conversion efficiency, standing crop, and diet, it is
clear that initial food web models should be limited to season, or
separately iterated over each season.
Anomalies in the Westcott Bay food web are apparent, even at the
highest trophic level where the data were assumed to be the most precise.
To assess the accuracy of estimates of annual production of secondary
consumers, yearly food intake of English sole was compared with its
328
-------
Appendix Table G-3.
Seasonal growth rates and conversion efficiencies,
Westcott Bay.
Staghorn sculpin
English sole
Starry flounder
Apr-May
July-Aug
Aug-Sept
Sept-Oct
Mar-Apr
Apr-Jun
July-Sept
Sept-Oct
July-Aug
Aug-Sept
Sept-Oct
Daily
weight
change (g)
0.02
0.13
0.90
0.05
0.01
0.07
0.07
0.13
0.03
0.05
0.20
Daily
intake (g)
Conversion
efficiency
(weight change)
intake (%)
0.36 ± 0.36
1.34 ± 2.56
3.42 ± 9.12
0.06 ± 0.04
0.24 ± 0.20
0.78 ± 3.42
0.24 ± 0.40
6
10
3
17
29
9
21
329
-------
Appendix Table G-4. Estimated annual production (wet weights) of
secondary consumers in Westcott Bay, San Juan
Island.
Species
Annual
t-
production, g/m
Staghorn sculpin
Starry flounder
English sole
Snake prickleback
Shiner perch
Penpoint gunnel
Surf smelt
Total
2.10
0.09
2.10
0.90
1.60
0.02
1.60
8.41
330
-------
Appendix Table G-5. Seasonal changes in standing crop of secondary
consumers at Westcott Bay, given in grains per square meter.
July 1974
August
September
October
November
December
January 1975
February
March
April
May
June
July
August
September
4.09
1.11
4.16
3.80
1.71
0.91
0.24
0.13
0.04
0.13
0.20
0.87
0.94
6.60
331
-------
production. For an annual production of 2.1 g m 2 and 10% growth
efficiency, English sole would have to consume 21 g m~2 yr"1. Annual
consumption rates estimated from daily consumption are 0.35-0.50
g m~2 yr"1. This error factor of 40-50 shows that more information is
still necessary even at the level of higher consumers. Possible sources
of error are: (1) Daily intake rate of two stomachfuls is too low for
rapidly growing juveniles. (2) Ten percent growth efficiency is too
high. (3) Mean growth rate is too high—it may be nearer the low end
of the range during most of the growing season. (4) Intake estimates
from partly digested stomach samples are too low. (5) Population biomass
estimates are in error. These feeding and growth rates could be more
accurately measured by laboratory studies.
If such great discrepancies exist between feeding and growth rates
at high trophic level, even greater errors may be expected for the
primary consumers where less quantitative data were available. Metabolic
studies have been conducted for several species of amphipods (Chang and
Parsons 1975; Halcrow and Boyd 1967). Information on particle selection
and assimilation efficiency is also known for species of various taxa.
However, this knowledge is quite patchy. A concentrated effort on the
primary consumers of an area must be undertaken to estimate standing
crop, feeding and growth rates, and production.
An important subsystem of Westcott Bay was overlooked initially in
efforts to simplify the system. This food web consists of the large
macroinvertebrates such as starfish, bivalves, crabs, and anemones
that are typical of most eelgrass areas. These macroinvertebrates are
suspension feeders, macroalgae grazers, and carnivores, and therefore
represent unaccounted for nodes and linkages in the food web. A
comprehensive bioenergetics analysis of any habitat as a whole will
have to incorporate every component system despite its complexity.
It is assumed that after identifying and quantifying the principal
energy pathways in a food web, the effects of perturbations can be better
assessed. Three possible outcomes of a perturbation are possible for a
population: (1) Population numbers decrease, (2) population numbers
remain constant but the mean weight per individual decreases, (3) the
population dies or leaves the area. Knowing the mobility of the population
and the ability of individuals to switch to different prey, as well as the
basic information on growth and feeding rates and production, would be
necessary to predict the outcome.
332
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Miller, B.S., C.A. Simenstad, K.L. Fresh, F.L. Funk, W.A. Karp, S.F.
Borton, and L.L. Moulton. 1977. Puget Sound baseline program; near-
shore fish survey. Final Kept., July 1974 - June 1977. Fish. Res.
Inst., Coll. Fish., Univ. Washington, Seattle. 220 pp.
Sand-Jensen, K. 1975. Biomass, net production and growth dynamics in an
eelgrass population in Vellerupvig, Denmark. Ophelia 14:185-201.
Thayer, G.W., S.M. Adams, and M.W. LaCroix. 1975. Structural and
functional aspects of a recently established Zostera marina community.
Est. Res. 1:518-540.
334
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4. TITLE AND SUBTITLE
FOOD WEB RELATIONSHIPS OF NORTHERN PUGET SOUND AND THE
STRAIT OF JUAN DE FUCA -- A Synthesis of the Available
Knowledge
TECHNICAL REPORT DATA
u Instructions on the reverse before completing)
1 REPORT NO
3. RECIPIENT'S ACCESSION NO.
5. REPORT DATE
September 1979
6. PERFORMING ORGANIZATION CODE
7 AUTHOR.S) Charles A> simenstad, Bruce S. Miller, Carl F.
Nyblade, Kathleen Thornburgh, & Lewis J. Bledsoe
Fisheries Research Incrit.nt.p! llniv nf Washington
8. PERFORMING ORGANIZATION REPORT NO
NOAA Report No.
r I i>nci ica—rvcacoi in—iiia <- i L u L.IT ,—mi i v .—
9 PERFORMING ORGANIZATION NAME AND ADDRESS
MESA Puget Sound Project
National Oceanic and Atmospheric Administration
Tower Bldg.,Room 120
7600 Sand Point Way NE, Seattle, WA 98115
10. PROGRAM ELEMENT NO.
EHE 625-A
12. S°ONSORING AGENCY NAME AND ADDRESS
Office of Energy, Minerals and Industry
Office of Research and Development
U.S. Environmental Protection Agency
Washington, D.C. 20460
11. CONTRACT/GRANT NO.
IA6 No. D6-E693-EN
13. TYPE OF REPORT AND PERIOD COVERED
Final Report (3-77 thru 12/78)
14. SPONSORING AGENCY CODE
EPA-600/17
15 SUPPLEMENTARY NOTES
16 ABSTRACT ~~~~~
Substantially increased petroleum transfer and refining activities are anticipated
in the northern Puget Sound and Strait of Juan de Fuca areas. These activities will
likely increase the chances of chronic and/or acute oil inputs into the marine
environment. These areas are currently stressed to only a limited degree by
petroleum. The study reported here was undertaken to identify biologic means by
which petroleum constituents may be transferred from lower to higher trophic level
populations and to identify those populations and pre-predator links that are of
critical importance to maintenance of major biological communities. Interruption
of these critical links by loss of important prey groups could drastically change
the composition and/or productivity of higher trophic level populations. The study
was conducted by scientists at the Fisheries Research Institute, University of
Washington, and involved primarily a compilation of existing data.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS I^IOENTIFIERS/OPEN ENDED TERMS
Ecology
Environments
c. COSATl I icId/Group
Release to Public
'is 'Si'-.;. PIT- CLASS 'Tins Repcrtl j 21. NO. OF PAGES
Unclassified ' 334
' 20 -3 t C _ t= \ T v C LASS / This pugg;
Unclassified
2220-;
|22. PRICE
EDITION ,5 OfiSOLETt
335
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