i 1 5 S IT

Lasered CED

State of DEPARTMENT OF

PROGRESS REPORT No 145

Food Habits of Pacific Sailfish And Their Potential Competitors and Predators In the Marine Waters of Washington August 1978 to September 1979

Kurt L Fresh Rick D Cardwell Robert R Koons

August 1981

This project partially supported by grants from PacifiC Northwe t RegIOnal Commission and NatIOnal Manne Flshene Service with funds from the Anadromous FI h ConservatIOn Act State of Washington DEPARTMENT OF FISHERIES i PROGRESS REPORT NO 145

I

FOOD HABITS OF PACIFIC SALMON BAITFISH AND THEIR POTENTIAL COMPETITORS AND PREDATORS IN THE MARINE WATERS Oi WASHINGTON AUGUST 1978 TO SEPTEMBER 1979

Kurt L Fresh Rick D Cardwe11 Robert R Koons

August 1981

1 This project was partially supported by grants from the Regional Commission Grant No 10890606 and the National Marine Fisheries Service Grant No 9ABD WA1H with funds from the Anadromous Conservation Act P L 89 304 2 Current address Envirosphere Company Be11evue Washington ABSTRACT

During the first segment of a multi year project the feeding ecology and of trophic interactions of salmon baitfish and other selected marine fish were studied between August 1978 and September 1979 of Sound Pelagic zooplankton occurring in nearshore surface waters puget in near were sampled to compare with the prey consumed by fish occurring shore habitats Food habits of subadu1t and adult chinook and coho salmon

from the Pacific near the mouth of the were also studied

We beach seine townet purse seine and hook o employed sampling techniques and line that have been proven effective in capturing salmon and baitfish from habitats they utilize during their ontogeny in Puget Sound

The contents of 3 813 2 838 full and 975 empty stomachs from 24 species

of fish were analyzed Ca1anoid copepods euphausiids brachyuran larvae insects 1arvacea and gammarid and hyperiid amphipods were the primary food items of juvenile salmon and baitfish occupying shallow sublittoral and near shore pelagic habitats 20 m in depth The diets of juvenile 150 mm in

were length sand lance and surf smelt in these habitats similar comprising mostly smaller invertebrates such as harpacticoid and cyc1opoid copepods and suggesting these species may compete for food The

and coho salmon 200 mm from sublittoral prey spectra of juvenile chinook and nearshore pelagic habitats were similar comprising mostly large crusta between ceans such as brachyuran crab larvae and suggesting competition chinook and coho salmon juveniles in these habitats Diets of larger coho salmon

2 200 mm and herri ng 150 mm caught in more offshore pe1agi c habitats 20 m in depth of Puget Sound were primarily larger euphausiids amphipods and brachyurans whereas larger 200 mm chinook mainly ate fish mostly herring Chinook in this habitat likely would compete with other piscivorous species such as and hake On the other hand coho and their on similar herring may compete in this habitat because of emphasis

invertebrate prey

Subadult and adult chinook and coho salmon from the Pacific Ocean near

the mouth of the Columbia River ate mostly fish northern and

sme 1 t

I Four species of fish all salmonids consumed juvenile salmon although rates of predation were relatively low However the implication of these low predation rates cannot be established without knowledge of the size of u predator standing stocks and consumption rates I Brachyuran larvae calanoid copepods barnacle larvae and hydrozoans were the dominant nearshore pelagic zooplankters The diet of juvenile in nearshore surface herring was the most similar to zooplankton occurring waters whereas the diet of juvenile chinook was least similar TAlr or CONTrN rs

Page

LIST OF T ABL ES i i

LIST OF FIGURES i i i

INTRODUCTION 1

MATERIALS AND METHODS 2

I I Study Areas 2 Study Sites 2 i Techni 2 J Samp1 ng ques Target Speci es 5 Sample Processing 7 Oata Analysi s 7

RESULTS AND DISCUSSION 9

Food Habits by Species 9

Chum Salmon 9

Sublittoral Habitats 9

Pe1agi c Habi tats 9 Geographic Comparisons 11 1 11 Subli ttora1 Habi tats 11

Nearshore Pelagic Habitats 11

Offshore Pelagic Habitats purse seine collections 11 Offshore Pelagic Habitats angler collections 14

Coho Salmon 23

Sublittoral Habitats 23

Nearshore Pelagic Habitats 23

Offshore Pelagic Hahitats purse seine collections 23 Offshore Pelagic Habitats angler collections 23

Paci fi c Herri ng 27

Sublittoral Habitats 27

Pelagic Habitats 27 Other Baitfish 31

Other Mari ne Fi sh 31

Pink Sa 1 mon 35

I Cutthroat 35 Page

Steelhead Trout 35

Pacific 35

Pacific Hake 35

Pac i fi c T omc0 d 36 I 36 Walleye Pollock

Rockfi sh 36

Cabezon 36

Ameri can Shad 36

Threespine Stickleback 36 37 Spi ny Dogfi sh Pacific Staghorn Sculpin 37 Great Sculpin 37 Starry 37

Butter 37 a 37 Predation on Juvenile Salmon 38 Competitive Interactions 3q Pelagi c PrfY Selecti vi ty ACKNOWLEDGMENTS 43

LITERATURE CITED 44

APPEND ICES 46

i LIST OF TABLES

Table Page

Pacific 1 Sampling frequency by gear type in Puget Sound anrl the 6 Ocean from August 1978 September 1979

and stomachs 2 Target species and number of full empty analyzed 1978 1979 8 by gear type in Puget Sound August September

3 Geographic comparisons of chum fo d habits in Puget Sound 1979 12

4 Food habits of chinook salmon from February and May 1979 purse seine collections in puget Sound 15

5 Percent biomass of the major prey items of Pacific Ocean sport caught chinook by size class May September 1979 21

6 Food habits of coho salmon from February and May 1979 purse seine 25 collections in puget Sound

7 Percent biomass of the major prey items of Pacific Ocean sport 29 caught coho by size class May September 1979

8 Food habits of Pacific herring from February and May 1979 purse seine 32 collecti ons in Puget Sound

I 9 Percent numeric and gravimetric composition of nearshore surface 40 pelagic zooplankton from puget Sound February September 1979

i i LIST OF FIGURES P 1 H 9 rc

locations of 1 Map of the puget Sound study area showing general CPS and SPS sampling sites large arrows 3

2 Releases of chum chinook and coho salmon from hatcheries pens i 1951 1979 4 and egg incubation boxes in South Puget Sound

3 Prey spectrum of chum salmon caught in shallow sublittoral upper and nearshore pelagic lower habitats of Puget Sound broken rlown by percent numeric and gravimetric composition and prey frequency 10 of occurrence

sublittoral 4 Prey spectrum of chinook salmon caught in shallow upper and nearshore pelagic lower habitats in Puget Sound broken down by and of percent numeric and gravimetric composition prey frequency 13 occurrence 1978 1979

in Sound 5 Prey spectrum of chinook salmon caught by anglers Puget broken down by percent numeric and gravimetric composition and 1978 1979 0 prey frequency of occurrence August September v

total fish in 6 Monthly changes in the percent biomass of herring and and SPS the diet of chinook salmon caught by anglers in CPS upper 18 lower August 1978 September 1979

from of 7 Length frequency distribution of Pacific herring the stomachs chinook salmon caught by anglers in Puget Sound August 1978 September 19 1979

in the Pacific 8 Prey spectrum of chinook salmon caught by anglers Ocean near the mouth of the Columbia River broken down by percent numeric and gravimetric composition and prey frequency of occurrence 20 May September 1979

from the stomachs 9 Length frequency distributions of northern anchovy Pacific of coho A and chinook B salmon caught by anglers in the 1979 2 Ocean near the mouth of the Columbia River May September

in shallow sublittoral 10 Prey spectrum of coho salmon caught upper broken down and nearshore pelagic lower habitats of puget Sound and percent numeric and gravimetric composition prey frequency by 24 of occurrence 1979

Sound broken 11 Prey spectrum of coho salmon caught by anglers in puget and fre down by percent numeric and gravimetric composition prey 1979 26 quency of occurrence March September

i i i F i gu re Page

in the Pacific 12 Prey spectrum of coho salmon caught by anglers Ocean near the mouth of the Columbia River broken down by of occurrence percent numeric and gravimetric and prey frequency 28 May September 1979

in shallow sublittoral 13 Prey spectrum of Pacific herring caught lower hahitats of Sound upper and nearshore pe1aqic puget I and broken down by percent numeric and gravimetric composition 1978 1979 30 prey frequency of occurrence

in the shallow sublittoral 14 Prey spectrum of surf smelt caught habitats of puget Sound broken down by percent numeric and gravi metric composition and prey frequency of occurrence February 33 Au gu st 1979

sub 15 Prey spectrum of Pacific sand lance caught in the shallow littoral habitats of Puget Sound broken down by percent numeric and gravimetric composition and prey frequency of occurrence 34 February August 1979

16 Density numbers m3 of nearshore surface pelagic zooplankton from inshore 3 4m in depth and offshore 20 25m in depth tows 41 in CPS upper and SPS lower February September 1979

17 gr of nearshore surface pelagic zooplankton I Standing crop m3 4 from inshore 3 4m in depth and offshore 20 25m in depth tows 1979 42 in CPS upper and SPS lower February September

i i i 1

INTRODUCTION Pacific The consequences of trophic interactions on the production of

salmon spp have recently begun to occupy the attention of and management agencies Such factors as food limitation competition predation involving salmon and other marine fish especially baitfish species lance such as Pacific herring C1upea harengus pa11asi Pacific sand Am d he and surf smelt JP es pre io may signifi

of salmon e Gonsolus 1978 cantly influence the growth and survival g Some Healey 1979 Simenstad et a1 1980 Walters et a1 1978 of our proposed and ongoing salmon enhancement programs could through inappropriate exacerabate the species mixtures release schedules etc inadvertently and thus reduce our consequences of deleterious trophic interactions ability to produce these fish Our understanding of food web relationships in the ecological communities that salmon reside in is presently incomplete Clearly a better understanding of trophic relationships is required so that factors identified as limiting salmon production can be incorporated into management plans and models to help maximize salmon production

I e g Johnson 1974 1977 The Washington State Department of Fisheries WDF initiated the Sa1mon Herring Predator Competitor Interactions Project to address these fundamental the concerns Objectives of this multi year project are to characterize feed and other ing ecology and trophic relationships of salmon baitfish selected species of puget Sound fish Results of Phase I of the project occurring from August 1978 to June 1979 and funded by the Pacific Northwest Regional Commission have been presented in Fresh and Cardwell 1979 This report to of Phase includes an expanded version of those results in addition results II studies occurring between July and September 1979 funded by the National Marine Fisheries Service Results interpretations and conclusions pre sented in this interim report are preliminary and subject to revision when the data from the whole multiyear project are analyzed Objectives of this phase of the project were to 1 assess the food habits of chinook 0 tshawytscha coho 0 kisutch and chum 0 ketal

salmon in puget Sound and of sub du1tand adul tinook and coh i

the nearshore Pacific Ocean area near the mouth of the Columbia River

ubadult salmon are considered those greater than 200 mm Fork Length that are sexually immature 2

2 determine the food habits of herring other baitfish and selected species and of marine fish that may be competitors or predators of salmon herring 4 3 define competition and predation of the species studied and compare in food of salmon and herring that occur in nearshore 20 m depth habi I tats to the available nearshore surface pelagic zooplankton

MATERIALS AND METHODS

Stu dy Are habits of salmon In Puget Sound stomach samples for food analysis Sound CPS baitfish and other species came from two regions Central Puget SPS south Possession Point to the Tacoma Narrows and Southern puget Sound because 1 of the Tacoma Narrows Fig 1 These two regions were compared oceanographic conditions may vary between areas and consequently produce different feeding conditions and 2 they are the first marine areas en

South c countered by juvenile salmon from major enhancement programs puget recent salmon Sound is the focus of a significant part of the state1s

enhancement efforts Much of the emphasis will be on increasing production has been subordinate of chum salmon a species whose culture historically

to chinook and coho Fig 2 the mouth of the To study whether predation in the Pacific Ocean off from the Columbia Columbia River might be limiting the production of coho coho salmon were obtained River stomachs from subadult and adult chinook and

from the charter boat fishery of Ilwaco Washington this was the only collec tion of specimens outside Puget Sound

Study Sites Island whereas Most sampling sites in SPS were located near Anderson 1 We those in CPS were primarily near Bainbridge Island Figure attempted as habitat to select sites that were similar with respect to such variables and of adjoining type beach and bottom substrate exposure composition habitats

Sampling Techniques efficient in collect We utilized sampling techniques that have proven their in ing salmon and baitfish from habitats they utilize during ontogeny et al 1978 Fresh et al 1979 puget Sound Bax et al 1979 Cardwell were collected as Healey 1978 Miller et a1 1977 Many specimens part 3

12J OO OO W 50

I

I

tI

KILOMITI

r o 0

00 0

fI

Fig 1 Map of the Puget Sound study area showing general location of CPS and SPS sampling sites large arrows CHUM SALMON CHINOOK SALMON

I I I COHO SALMON 30 lD a l

x

z a

I 20 U

o a f c c

I a r J I E 10 I j J r X

o

1955 1960 1965 1970 1975 1980

Fiq 2 Releases of chum chinook and coho salmon from hatcheries pens and egg incubation boxes in south Puget Sound 1951 1979

0 5

of other fishery research projects of WDF and sampling frequency varied with

Where we standarized gear type Table I possible sampling by collecting at night in order to minimize problems with gear avoidance and variability from vertical and horizontal migrations of fish and zooplankton Fish occurring in the shallow sublittoral habitats primarily salmon

and baitfish 150 mm of CPS and SPS were sampled monthly during periods I of minimal tidal exchange with a 37 m floating beach seine using methods described in Miller et al 1977 Pelagic zooplankton occurring in near

shore surface waters were sampled monthly concurrent with beach seining using a push net procedure Cardwell et al 1978 Zooplankton were 4 m collected 1 m below the surface at inshore 50 m offshore in water 3 in depth and offshore 250 400 m offshore in water 20 m in depth stations Tows were made parallel to shore directly adjacent to each of two beach seine sites in each region Specimens from nearshore pelagic habitats 20 m in depth were col lected by townet 3 1 X 6 1 m by 15 m long with mesh grading from 76 mm to 6 4 mm during cruises conducted by the Marine Fish Program of WDF

methods are described by Penttila and Stinson in prep Fish occurring with in more offshore pelagic habitats 20 m in depth were collected a

purse seine 500 m long by 55 m deep with 2 cm mesh In puget Sound stomachs from subadult and adult chinook and coho sal

mon caught by anglers were collected by WDF s Harvest Management Division Chinook stomachs were collected beginning in August 1978 in SPS only chinook

in CPS and coho in both areas were collected beginning in January 1979 During the 1979 sport fishing season May 12 to September 2 in the Pacific Ocean stomach samples were collected near the mouth of the Columbia River

from the Ilwaco fishery Coho 2 and 3 year olds and chinook 2 years were the principal target species Similar stomach sampling methods were employed in both Puget Sound and the Pacific Ocean except that Pacific Ocean fish were processed immediately upon capture whereas puget Sound fish

were up to 4 hours old when processed A mid water trawl with a 6 1 x 6 1 m opening was used to collect herring in the fall of 1978 during hydroacoustic herring surveys conducted in SPS by WDF s Marine Fish Program

Target Species Although chinook coho and chum salmon and Pacific herring were the 1978 1979 in Sound and the Pacific Ocean from August September Table 1 Sampli ng frequency by gear type Puget

Jan ept Area gear Aug

Puget Sound xY X X X X X X Beach seine X Townet X X X X Purse seine X X I Midwater trawl 0 I xY X X X X X X X Zooplankton tows X X X X X X X X X Ang1erY X X X X X

Pacific Ocean X X X X X Angler

1 until Ma rc h i n C P S Beach seine and tows were not begun 7 December 1978 Only SPS was sampled August through 7

primary target species a variety of their potential predators and competitors

were also studied Table 2 Literature sources and unpublished data from

the University of Washington were used to select these potential competitors 4i and predators Those species which were captured are listed in Table 2

I Samp roce i ng Whole fish and stomachs were preserved in 10 formalin with a pH of 7

and salinity of 9 0 00 Stomachs from specimens 350 mm were generally

excised in the field For each month and gear type a pool of specimens of

each species was compiled from as many of the sites within each region CPS content or SPS as possible and specimens for stomach analysis randomly chosen from this pool All specimens selected for stomach analysis were measured fork length FL all sa1monids standard length SL all other fish and weighed nearest 0 01 g Stomachs were analyzed using standardized procedures describing the frequency of occurrence and the numeric and gravimetric propor

tion of prey Cross et a1 1978 Terry 1977 Qualitative measures of digestion 1 complete to 6 no digestion and fullness 1 empty to 7 full

of the stomachs also were made

Food organisms were identified to species where possible although pre cision in identifying organisms depended on the degree of prey digestion Con prey life history stage and the staff1s identification capabilities sequently food habits data frequently encompassed several taxonomic levels

e g crustacea brachyura Cancer for perhaps the same or homologous species For the most part these distinctions were retained although the contribution of completely unidentified i e digested material was ignored in calculating the percentages that prey taxocenes contributed to total prey biomass and numbers A taxonomic breakdown of all invertebrates including

common names identified from stomach contents and plankton samples is pre sented in Appendix 1

Data Analysis

All data were cooed on computer sheets according to National Oceano graphic Data Center Marine Ecosystems Analysis NODC MESA specifications punched on 80 co1umn IBM cards and read onto computer tapes Programs developed by the University of Washington and WDF were used in data analysis We have depicted some of the food habits data graphically using a modi fication of the Index of Relative Importance IRI Pinkas et a1 1971 8

I ed T1able 2 Target species and number of full and empty stomachs ana1y by gear type I in Puget Sound August 1978 September 1979 H er

H I OI SJ cn s proc sed Townet Purse seine Mldwater trawl lotal IIpach seine n ngleJT r F ErE r E Common name Sclentlfic name FY i r uoE r uE H 23 12 2 0 0 0 0 791 Chum salmon OncorhynL Hls keta 729 16 58 6 105 7 157 47 3 7 147 0 0 04 2U Chinook salmon O Eh a yl scha 105 31 2 157 15 61 720 U U 916 24 Coho salmon O H u tel 135 10 1 174 30 1 2 63 161 11 U II tlA 2111 5H 127 r aclflc rrlnQ Clujie ha l ngus all h 0 II 0 0 U U II IN 6Q l tlosu s 119 69 0 Surf smelt 1 0 41 40 lilOmcsus 41 40 0 0 0 0 0 0 0 S and I ancp lIriiriiodyTI S h xaii cru 0 0 0 0 0 0 0 0 21 2 Cutthroat trout 5iiliiiii c la k i 21 2 0 17 3 15 I 0 0 33 4 Steelhead trout S iliiTri rr I 0 0 4 1 0 0 II 3 U OrbUs liil o I 0 0 15 1 0 2 1 0 0 0 I 0 10 2 0 17 P acHlc cod r adiismacllephalus 0 15 7 9 I 0 0 25 15 Pacific hake RerTiicClus proouct 1S I 7 0 7 0 0 0 0 0 16 0 p tomcod 9 0 0 0 acific Mlcrogaaus proxlmus 5 5 0 0 0 22 3 24 2 0 0 I Walleye pollock Theragrachiilcogramma 0 0 0 0 6 0 0 0 6 0 r rockflsh seDaStes CaiirTilus o 0 Coppl 0 10 4 0 0 10 4 Black rockfish Smelanojis o 0 0 0 0 0 1 0 0 0 0 0 0 Yellowtall rockfish S TiavTdus o 0 0 0 0 0 0 1 0 S cnthys marmoratus I 0 0 0 0 0 Cabezon corpaem 0 o 0 0 0 6 0 0 0 0 6 0 Amerl can shad sap i dTsSTma 0 0 0 0 0 0 0 0 7 0 T hreesplne stickleback lmerosteus aculeatus 7 0 acantliTas o 0 0 0 0 0 0 3 0 0 0 3 Spiny dogfl sh 5ijUaliis 3 0 0 0 0 0 0 n 12 Pacific staghorn Leptocottils armatus 12 3 0

sculpin 0 0 0 0 0 0 0 0 o o Great sculpin Myxocephalus poryacantnocephaIus 0 3 o o 0 3 flounder stelTatus 0 0 0 0 0 0 Starry PlillCliUlys o 0 l ole 0 0 0 0 0 0 I 0 o 1 Butter sole Is psetta lR4 1m 115 573 1m O lJ 3l14 llfl 01 fl3f1 1175 TotalS fl3

l F Full

Y E Fmpty

n d go S

1i 9

These three axis graphs illustrate frequency of occurrence the proportion of stomachs containing a specific prey organism plotted cumulatively on the horizontal axis and percentage of total prey abundance and percentage of and below the horizontal total prey biomass normalized plotted above axis respectively The prey categories have been arranged from left to right by decreasing frequency of occurrence and include only those occurring in at

least 1 of the stomachs

RESULTS AND DISCUSSION

Food Habi tDJ SFeci Chum salmon

Sublittoral habitats Juvenile chum salmon were collected by beach

seine in shallow sublittoral habitats from March through August 1979 with most caught in May and June Of the 245 chum stomachs analyzed from this

habitat only 7 were empty The mean fork length of chum from shallow sub

littoral habitats one standard deviation was 69 22 mm FL Mean stomach

fullness and digestion were both relatively high x 4 4 and x 4 3 respectively suggesting that most chum had recently fed Chum caught in the shallow sublittoral had fed predominantly upon ca1anoid copepods primarily Ca1a us spp Aetedius spp and Epi1abidocera amphi rie larvacea Oikop1eura harpacticoid copepods and euphausiids Fig 3 Primary in prey of juvenile chum was ca1anoids in March harpacticoids April euphausiids in May ca1anoids in June decapods and 1arvaceans in July and myodocopa in August The importance of these prey in chum diets generally is consistent with

other studies e g Fresh et a1 1979 Simenstad and Kinney 1978 Simenstad et a1 1980 although harpacticoids were somewhat less important than some

other studies found e g Simenstad et a1 1980

Pelagic habitats Of the 81 juvenile chum salmon x 100 28 mm FL stomachs collected by townet in nearshore pelagic waters 28 were empty

Stomach fullness x 3 3 and digestion x 3 8 indices were both

lower than in shallow sublittoral habitats The diet of townet caught fish

based on percent biomass was largely euphausiids gammarid amphipods and 4 brachyuran crab larvae mostly Cancer spp and pinnotherid Fig 3 Euphausiids while accounting for the greatest proportion of the biomass 37 occurred in only 18 of the stomachs Calanoids were not as prominent gravi

metrically as some other prey but were eaten by 48 of the fish I o I

rl I en D CD Q2 Do Cen 8 xl rfT1 en NfT1 N 0 rfT1 2o1 I X1 mr en o NN E 1 en PN en ON oo

o

ABUNDANCE Olo ptera BY 01 InsectaPsocoptera TION o S

PCT o

WEIGHT No BY dea dea o dea ra ta Brachyrhyncha a rl dOl latus 1 hyu all Ca c m o Aph1 Cope Hyperll ta Bra ta da Decapoda dea da poda rl poda o 1 OpOl COMPOSITION eocyema ychaeta1 PCT Calanolda Euphauslacea arvacea AmOhl Cyc Pl Teleoste1 Cancrldea Euca GaTl111arlAnomuraHomopteraCopepodaDeca Po CumaceaPsyllldaeUrochorda1yodocopaLeptocottU o o Harpactlcolda o U1 o oo U1 o Noo NU1o oo U1 o oo U1 o

rl IC1113en D 002 Do Cen 8 enDxl rfT1 en r z o 1I or en Co NJ CD E1 en en 0U1 U1 Ol U1 oo

co

ABUNDANCE m o BY

o

COMPOSITION No PCT o

WEIGHT No BY ra o Brachyrhynchaa ta a 1 pod 1 hyu adocera Euc mo Deca acea Cope Brac Hyper11dea 1 da ra rl poda o COMPOSITION anolda1 adocera1 PCT Ca Cancrldea Garrrnarldea Amphlpoda Euca Euphaus CyclopOlda Larvacea Deca Anomu Cumacea CopepodaTeleostelMyodocopaPolychaetaOstracoda CChaetognatha

Harpactlcolda I 1

L I I 1 i j i I 8 I I 1 S 1 a 0 c0 01 01

c D 0 C Zrl a orl 0 Zr

0 l 0c 3 VI 0 0 VIc 0 rt rt S 0 to w C S lP VI 0lP l S c 0 l l0 VI 0 3 3 30 lP l lPrt tos r 0 rt 0rt o C c lP c l0 00 P S 03rt o 33 lP0S VI sr SC 3lP3 0 nc to to 0 3SC OlPl3 0 o 3 0lP 0lP rt 3 30 lP S l 03010 0 50 30 lPrt S lVl lo30oVI rtrtO o 0 0 S lP S lP 00 c lP 3l ol c S SlP 3l lP 11

In May 1979 stomachs of 14 12 with food larger chum x 290 13 rom FL

were collected by purse seine Brachyuran crab larvae were the primary prey item particularly Cancer spp which occurred in 83 of stomachs and accounted for 68 and 90 of the total numbers and biomass of prey respectively

Geographic comparisons Utilizing months of adequate sample sizes April and May beach seine and June townet it was possible to compare chum diets geographically Table 3 Some differences in prey composition were apparent For instance larvacea were relatively unimportant in the

diets of chum from CPS but were important in SPS while fish larvae were important prey in CPS but not in SPS

Chinook salmon

Sublittoral habitats Most chinook collected in shallow sublittoral

habitats by beach seine were juveniles x 124 68 mm FL and primarily occurred from June through August Only 5 of the 111 stomachs analyzed

were empty Chinook caught in this habitat consumed a diverse array of ben thic epibenthic and pelagic organisms including fish primarily herring and sand lance brachyuran crab larvae mostly Cancer spp polychaetes insects and hyperiid and gammarid amphipods Fig 4 Primary prey of the juvenile chinook was fish and crab larvae in June and July and fish poly chaetes and insects in August The occurrence of insects is of particular note since they are probably surface drift from either rivers or directly off the land e g falling from plants along the shoreline

Nearshore pelagic habitats Of 112 juvenile chinook salmon x 118 26 rom FL obtained for analysis from townet samples in nearshore pelagic habitats 6 were empty Although occurring in only 10 of stomachs euphausiids accounted for the greatest proportion 32 of the prey biomass Fig 4 decapod larvae primarily brachyura fish and polychaetes were other important prey in terms of gravimetric contribution Decapod larvae were the most important numeric component of the diet contributing 55 of

the total numbers of prey eaten As in sublittoral habitats numerous vari

eties of insects comprised a significant dietary component of these chinook Fig 4 especially in late summer

Offshore pelagic habitats purse seine collections Chinook salmon were collected by purse seine in February n 130 and May n 74 and were 12

Table 3 Geographic comparisons of chum food habits in Puget Sound 1979 n Beach selne lownet Aprfl JUne June Parameter CPS sPS SPS

Predator characteristics Woo exami ned 9 20 26 49 35 17 No empty 0 0 6 2 3 0 Mean fork 1ength mm 54 51 81 65 92 100 Mean full ness 6 0 4 7 4 0 4 2 3 4 3 3 Mean digestion 4 9 4 6 3 8 4 1 3 7 3 8

Major prey items percent biomass Ca1anoida 1 15 46 68 22 15 Harpacticoida 18 67 1 2 0 0 Fi sh larvae 81 3 29 1 1 1 Larvacea 0 11 0 23 0 36 Decapoda 1 0 22 2 37 47 Euphausiacea 0 0 1 7 16 1 Chaetognatha 0 0 0 0 15 0 L

CHINOOK SflUIClN AOJUSTEO SAMPLE SIZE 105 LENGTH MM 124 0 5 0 67 6 WT OMS X 50 24 5 0 140 64 100

AD

l

Oell 60 U I I 0 lD 0 o U 0 c o 0 u 40 w uro

Cl U 20

I J a o I

u c 2 20

U

lD w W W z 40 0 N I 0 8 I 0 o 0 o 0 0 U a r o U a x Cl w OJ l 60 a U u a x raJ OJ J l Y Cl OJ 9 VJ U W w 0 0 w w o a umruWtQOmWrou i o OOfoc t UJroi 80 o a a U c 3 uowOUQ QJU W u o w l Ql ra 0 u U E iJOQJC C a E o gSc 8J U n r xi n l t r Cl r r f V1 0 0 u

100 4 o 50 100 150 200 250 300 350 400 450

CHINOOK SALMON AOJUSTEO SAMPLE SIZ 105 LENOTH MM X 117 8 5 0 25 6 WT OMS X 21 77 S O 20 77 100

w u z 60 a OJ z i 60 lD

z 8 40 u

a J

U 20

u a 0

13 20

w lD W 0 40 W li 0

0 1 n m I c 1 11 1 Il Q on 0 W 0 muo w 0 0 U W W W o a c 0 a U JtO1JroOco a U 0 0 0 o j w 0 c U o u 0 OlfO Q U w w OJ OEcs r 60 c U a 0 a l E 0 a o c l u W W t c 0 oooc c 0 u Ii cv a C 0 r u u w uor C JU

100 0 50 100 150 200 250

CUMULATIVE FREQUENCY OF OCCURRENCE

Fi g 4 Prey spectrum of chinook salmon caught in shallow sublittoral upper and nearshore pelagic lower habitats in Puget Sound broken down by percent numeric and gravimetric composition and prey frequency of occurence 1978 1979 14

primarily 200 mm FL 18 of the stomachs were empty in Mayas compared to 25 in February Mean stomach fullness and digestion both decreased slightly from February to May possibly due to more rapid digestion in the warmer waters of May Their major prey was fish mostly herring although crustaceans euphausiids gammarid amphipods and mysids were also eaten particularly in CPS in February Tahle 4 Invertebrates accounted for the greatest numerical proportion of prey consumed 95 while fish made up most 80 of the prey biomass Chinook typically fed either on large numbers of invertebrates or

on several fish Chinook 350 mm FL tended to eat more invertebrates than

the larger chinook which ate more fish Herring and sand lance were the only fish positively identified from stomachs with herring occurring in 13 of stomachs with food and accounting for 62 of the overall prey biomass

Offshore pelagic habitats angler collections Considerable emphasis be was placed on the food habits of legal sized chinook salmon that could ob tained from the sport fishery because of concerns about their relationship as predators of herring in Puget Sound and of salmonid smo1ts from the Columbia River Of the 251 chinook stomachs analyzed 24 were empty 65 were from

CPS and 186 from SPS The average length of the chinook was 571 78 mm FL

were from Anderson Island 46 and Pt Gibson 23 and I Most SPS specimens

I most CPS specimens from Pt Jefferson 25 Elliot Bay 22 and Shi1sho1e I Bay 20 Prey digestion rated four or higher in 50 of stomachs indicating most Puget Sound chinook had fed relatively recently prior to being caught stomach in to contents were in general more digested summer probably due higher water temperatures There were no discernible temporal or spatial trends in degree of stomach fullness six fish I Chinook prey items included 13 invertebrate taxa and species Chinook usually had eaten only one or two prey categories x 1 4 and the I total number of categories varied little between months range 4 to 6 with fish puget Sound sport caught chinook were almost entirely piscivorous the total comprising 96 of the prey biomass Fig 5 Sixty percent of prey 2 biomass was herring 30 unidentified fish 5 gadids 0 2 sand lance 0 at northern anchovy ngr u1i mo dax and 0 1 shiner perch y ster

a93rega Herring were the most important food item in the diet of the sport caught in chinook Herring were a major dietary item each month occurring 44 of chinook stomachs with food The gravimetric proportion in diets was least in 15

Table 4 Food habits of chinook salmon from February and r ay 1979 purse seine collections in Puget Sound

February May Parameter Overall CPS SPS Overall CPS SPS

Predator characteristics No examined 130 50 80 74 14 60 14 5 9 No empty 33 19 14 Mean fork 1ength mm 286 298 281 315 272 323 Mean fullness 4 1 3 3 4 5 3 7 2 8 3 7 3 2 3 8 Mean digestion 4 5 4 4 4 5 3 7 14 3 2 4 3 1 Mean no prey 16 19 0 categories stomach

Major prey items percent biomass Herring 60 21 71 60 82 52 Total fish 66 39 75 93 94 83 Euphausiacea 19 1 23 4 0 5 Gammaridea 11 23 1 0 0 0 Mysi dacea 5 22 1 0 0 0 16

CHINOOK SALMON ADJUSTED SAMPLE SIZE 192 1404 79 LENGTH MM X 571 1 S O 78 0 WT GMS X 2729 o1 8 0 lQO

0 w e u z 80 u a 0 Cl z w 0 I VlO m a g 60 0 r 0 m uu 110 z Cl0 CJ 40

f CJ CL c CJ u 20

u CL 0

20 W 0 J 11

r m 11

z 40 Vl I CJ o 11

11 f I CJ 60 CL c CJ u

I 80 u CL

100 0 20 40 60 80 100 120

CUMULATIVE FREQUENCY OF OCCURRENCE

salmon in Puget Sound Fi g 5 Prey spectrum of chinook caught by anglers broken down by percent numeric and gravimetric composition and 1978 1979 prey frequency of occurrence August September 17

in winter and Fig 6 and was probably summer and fall and greatest spring of because there was usually a portion even higher than our results suggest advanced only could be ident the stomach contents that because of digestion occurred there were usually several per ified as teleost fish When herring whole from stomach x 2 2 The mean standard length of 120 herring SL 7 and the 66 were 75 chinook stomachs was 110 35 mm Fig majority or would thus seem to be 3 years old of age 115 mm SL Most herring consumed 1976 for the Strait of Georgia less a finding similar to that by Healey mouth of the Columbia River stomachs From the Pacific Ocean near the

FL 38 were were obtained for of 233 chinook x 539 132 mm empty in Sound fish was the primary food item analysis As was observed puget over 99 of the biomass Fig 8 of these chinook accounting for prey A11osmerus e1on juvenile Northern anchovy herring whitebait smelt rockfish were all identified chinook salmon unidentified smelts and juvenile far the dominant occurring in from stomach contents Anchovy was by prey 85 the overall biomass 58 of the stomachs and accounting for of prey of the diet for larger chinook Anchovy were a more significant component whitebait smelt were more in the 400 mm FL Table 5 whereas prominent When did occur in stomachs diet of chinook less than 400 mm FL anchovy whole was 2 4 The mean standard length of 159 the average per stomach was 118 18 mm SL Fig 9 similar anchovy measured from chinook stomachs chinook stomachs from Puget Sound to the size of herring found in sport caught similar in their Chinook from puget Sound and the Pacific Ocean were item both areas with invertebrates food habits fish was the major prey from between areas was that of relatively minor importance The major difference in the Pacific Ocean and herring in Puget the dominant fish prey was anchovy was This probably Sound although the size of herring and anchovy comparable and are abundant in Puget Sound reflects availability of prey since herring while River area of the Pacific Ocean anchovy relatively rare in the Columbia A number of other studies have also has the opposite abundance pattern e Kirkness found chinook subadu1ts and adults to be mostly piscivorous g their diet can consist 1948 Merkel 1957 Prakash 1962 although largely Caution should be used however of invertebrates e g Silliman 1941 based on fish Sport when examining the food habits of chinook sport caught chinook which are feeding on fish especially sampling may be biased towards in each area herring because herring is the primary bait used by anglers the chinook Thus and the sport fishery may not randomly sample population

as a whole these results may not truly reflect the population 18

CPS

100

I 90 I

I

I I 80 I I Total Fish I I I I Herring I 70 I I I I I I I Ul I Ul I I 60 I E I I 0 I I Iii I I I 50 I I I I E I I Ql I I I I I Q 40 I Cl I I I 30 I I I

I 20 I I

I I I 10

0 AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP

SPS

100

I

90 I I I I I I I I I I I I 80 I I I I Total Fish I I I Herring I 70

I I I I I I Ul I Ul I 60 E it It Q m 50 E Ql Q 40 Cl I

30 I I I I I I I I I I I 20 I I I

10

0 AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1978 1979

biomass of and total Fi 6 Monthly changes in the percent herring g in CPS fish in the diet of chinook salmon caught by anglers 1978 1979 upper and SPS lower August September 1

20

19

III

II

III HERRING N 120 15 X 110 mm 14 SD 35 mm c 13 III 12 l1 11 4 0 10

9 OJ 0 E 8 l Z

6

3

411 4 0 60 65 70 15 80 85 90 95 100 105 110 115 120 1 5 110 13 140 145 150 1 180 165 I O 175 160 165 190195 200 U5 Standard Length mm

Fig 7 Length frequency distribution of Pacific herring from the stomachs of chinook salmon caught by anglers in Puget Sound August 1978 Sept ember 1979 20

CHINOOK SALMON ADJUSTED SAMPLE SIZE 145 LENGTH MM X 538 5 S D 131 7 WT GMS X 2519 31 S 0 1901 83 100

w u z 80 a CJ z l lD a 60

lD

Z

I 40

f

Q z 20 u

I U Q o J u

I

20 w x

lD 40 0 Z QJoQJ j J u a QJIOI O I ro Eo 0V 0 1Il 1 or3 VI f 0 S IOOro 60 QJ QJcus Q E D QJ 0 z Qj VI Jc c I OWW u j i I 80 U Q

100 o 20 40 60 80 100 120

CUMULATIVE FREQUENCY OF OCCURRENCE

of chinook salmon in the PdC Fi J 8 Prey spectrum caught by anglers ific Ocean near the mouth of the Columbia River broken down by percent numeric and gravimetric composition and prey freq uency of occurrence May September 1979 21

Table 5 Percent biomass of the major prey items of Pacific Ocean sport caught chinook by size class May September 1979 n Jor T iiQt T T f 9i ij of tfril Predator Characteristics 400 400 499 500 599 600 699 700 36 55 No exam ned 43 72 27 22 19 15 No emp ty 16 16

Major Prey Iterns percent biomass ruphausi acea 6 6 8 Brachyura 14 1 3 1 Te1eostei 13 2 10 5 3 2 5 1 118 Pacifi c 18 herri n9 5 0 Northern anchovy 36 7 73 4 94 1 86 0 88 2 Chinook salmon 9 Whitebait smelt 26 7 7 2 4 7 Smelts 8 4 11 15 Rockfishes 6 9 2 0 3 22

70 COHO

60

Northern anchovy N 341 X 125rrm 50 SD 14rrm

40

30

20

IU

10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100105110 115 120125130 135 140 145 150 155 160165

Standard length mm

70 CHI NOOK

60

Northern anchovy N 159 X J18I111l Il JUn

1i E i 30

20

10

10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100105110 115 120125 130 135140145 150155 160 165

Standard Length mm

10

of northern from the Fi g 9 Length frequency ditrioutionc anchovy stomachs of coho and chinook salmon caught by anglers in the P cific bcearr near the mouth of the Columbia River May September 1979 LJ

Coho salmon

Sublittoral habitats Most coho salmon caught by beach seine in shallow

sublittoral habitats were juveniles x 180 95 mm FL and were primarily

were caught from May through August Of the 145 coho salmon analyzed 7 empty The mean digestion factor was relatively high x 4 3 suggesting the coho had recently fed Coho caught in shallow sublittoral habitats had an extremely diverse diet that was comprised of benthic epibenthic and pelagic and which prey The primary prey was decapod larvae cancridae pinnotheridae accounted for 81 of the total organisms and 32 of the total prey biomass

Fig 10 Other important prey items included fish primarily herring gammarid and hyperiid amphipods and polychaetes

ita June lq79 was the that e orey agi only month juvenile coho salmon x 166 53 mm FL were analyzed from townet collections made in nearshore pelagic habitats Only two empty stomachs 6 were recorded out of 33 stomachs analyzed As in sublittoral habitats brachyuran crab larvae were their primary food item Fig 10

Offshore pelagic habitats purse seine collections From purse seine collections in offshore pelagic habitats 61 coho stomachs 20 were empty were analyzed from February and 111 4 were empty from May As was also the case with purse seine caught chinook coho stomach contents were more digested in May than in February Euphausiids fish primarily herring gammarid amphipods and decapod larvae were the dominant prey Table 6 and the coho typi cally ate ei ther large numbers of invertebrates or small numbers of fish

s l cE ecti ons Due to poor angler Qiis la9 Lta nJ catches coho stomach samples were not obtained from the Puget Sound sport fishery until March 1979 Eighty eight stomachs were collected from CPS and 67 from SPS overall 13 stomachs 8 were empty In SPS most specimens

48 came from Anderson Island and in CPS from Pt Jefferson 36 and

Shilshole Bay 22 The mean size of puget Sound sport caught coho analyzed

was 451 76 mm FL Fi5 contributed the greatest proportion of the overall

prey biomass 72 but occurred in only 30 of the stomachs Fig 11 c Identifiable fish in sport caught coho stomachs were herring juvenile chinook salmon sand lance gadids and cottids Invertebrate prey were a more 24

COHO SALMON ADJUSTED SAMPLE SIZE 135 LENGTH MM X 179 7 5 0 95 0 WT OMS X 107 29 5 0 218 45 100

w u z a 80 o z

a 60

m

z I

D 11 11 I I 40 Po 7

u u

u o

20 W 3

CU CU z 40 o 0 0 ov 0 c CU C

v C 0 o 60 OJ I CU 0 v CU c f CU CU 8 tOroro4 U o u OJ 0 C 0 0 c LJ 0 OJ OVlUc V U 0 U 0 11 10 0 C r 1O V0l II 00 0 80 u E OJ 0 0 C c c co a o ro 0 u v 0 E a 0 x w u E I E U I ji WalL

100 300 350 0 50 100 50 200 250

COHO SALMON ADJUSTED SAMPLE SIZE 31 0 172 LENGTH MM X 166 1 5 0 53 5 WT OMS X 8h R6 l0 100

J LJ Z 80 a o z

a 60

z o 40

o

c

LJ 20

u o

OJ 20 W 3 0 0 c v OJ c

u OJ z 40 0 T o I OJ OJ c 0 0 V 0 0 u CU c v v o 60 t E 0 0 c c J 5 o u w e g u u n

80 u

100 250 o 50 100 150 200

CUMULATIVE FREQUENCY OF OCCURRENCE

in shallow sublittoral Fig 10 Prey spect um of coho salmon caught habitats of uPRer and nearshore pelagic lower Puget Sound broken down by percent numeric and gravimetric comp o5 1979 t on and rey frequency of occurrence 25

Table 6 Food habits of coho salmon from February and May 1979 purse seine collections in Puget Sound

February May Parameter Overall CPS SPS Overall CPS SPS

Predator characteristics No examined 61 37 24 111 28 83 No empty 12 12 0 3 3 0 Mean fork 1ength mm 350 334 368 386 3V 407 Mean fullness 4 4 2 9 5 9 4 4 4 3 3 9 Mean digestion 4 5 4 2 4 9 4 0 4 6 4 4 Mean no prey 18 1 8 17 4 2 3 8 4 4 categories stomach

Major prey items percent biomass riJphausiacea 70 0 87 28 38 24 Gammaridea 14 27 11 21 15 23 Decapoda 0 0 0 17 31 13 56 0 26 14 27 Herri n9 10 Total Fish 12 56 2 32 15 38 26

COHO SALMON ADJUSTED SAMPLE SIZE 142 LENGTH MM X 451 0 S O 76 2 WT GMS X 1187 88 5 0 847 68 100

w u 80

Z l ID a 60

ID

Z o

I 40

fJ o Q z o u 20

U Q 0

20 w x

ID QJ 40 c Z o J 0 QJ Vl QJ 0 a Vl fJ QJ I o c 60 u I co 0 QJ QJI Vl c QJ QJ c o Vl o QJ cc u Vl J a 0 r 0 0 0 3 o C QJ E JItl 80 C a c 0 Ol U W a J C ItlQJ l I w Ii 00 Q j a J J 100 0 50 100 150 200 250 300

CUMUL T VE FREQUENCY OF OCCURRENCE

Sound Fig 11 Prey spectrum of coho salmon caught by anglers in Puget broken down by percent numeric and gravimetric composition and 1979 prey fr qu n y of ccurrence March September 27

diet than fish both numerically and in terms of significant component of the for coho 350 mm FL Primary invertebrate frequency of occurrence especi ally 4 11 of the total biomass euphausiids prey included gammarid amphipods and brachyuran crab larvae 10 the mouth of the Columbia River 471 full From the Pacific Ocean near Coho stomachs were analyzed from angler catches and 207 empty 31 coho x 566 86 mm FL than from the Pacific Ocean were considerably larger Sound coho their primary food item their puget Sound cohorts Unlike puget overall biomass Fig 12 and including was fish comprising 96 of the prey smelt chinook salmon northern anchovy surf smelt whitebait herring juvenile dominant item occurred in 38 of and juvenile rockfish Anchovy the prey biomass Anchovy was eaten the stomach and accounted for 65 of the prey consumed mm FL Table 7 The size of anchovy most extensively by coho 500 eaten by oceanic chinook the mean by coho was similar to that of anchovy from coho stomachs was x 125 standard length of 341 whole anchovy measured

14 mm SL Fig q

E i fi c h T1 g mm SL were Sublittoral habitats Juvenile herring x 96 12 cap seine in all months tured in shallow sublittoral habitats by beach sampled 15 were empty Calanoiq except April and of the 204 specimens analyzed crab larvae 23 and chaetog copepods 42 of the overall biomass decapod 13 while not naths 10 were the primary prey Figure Cyclopoid copepods nevertheless occurred in 45 a significant dietary component gravimetrically enumerated of the stomachs and represented 24 of the prey organisms

x 82 19 mm SL Pelagic h it ts Of the 155 juvenile herring habitats 41 were empty analyzed from townet collections in nearshore pelagic and also beach seine samples had low mean Herring examined from townet numbers of stomach fullness and digestion factors and relatively high empty or evacuate stomachs suggesting herring are primarily daytime feeders rapidly items in 51 contents Calanoid copepods were the primary food occurring the biomass of the stomachs with fond and accounting for 68 of prey Figure included 13 Other important prey of juvenile herring harpacticoid copepods but occurred and euphausiids Harpacticoids were insignificant gravimetrically in 37 of the stomachs and represented 24 of the total of prey organisms enumerated Euphausiids contributed 26 of the overall prey biomass but occurred in 4 of stomachs o 28

COHO SALMON ADJUSTED SAMPLE SIZE 471 LENGTH MM X 566 4 S D 86 1 WT GMS X 2426 01 S D 1149 01 100

UJ u z a 80 Cl z

lD a so lD

40

en o a x o 20 u

I U a o

I

5 20

0 Q Q lD i u Q ns ro ltS Q O z 40 E o I VI o I Q

Q I en 3 c c o so I w c t a l x j o p u JI

I 80 U a

100 o 20 401 SO 80 100 120 140

CU ULAJIVE F EQ ENCY OF OCCURRENCE

in Fig 12 Prey spectrum of coho salmon caught by anglers the Pacific Ocean near the mouth of the Columbia River broken down by percent numeric and grav imetric composition and prey frequency of occurrence May September 1979 29

of Pacific Ocean Table 7 Percent biomass of the major prey items sport caught 1979 coho by size class May September

F e a orre s of co E gfliJ J Predator Characteristics 400 400 499 500 599 600 699 700 220 30 No exami ned 47 70 311 24 78 71 11 No emp ty 23

Major Prey Items percent biomass 2 Cephalopoda 2 1 Euphausiacea 8 6 1 7 7 Brachyura 6 8 1 3 2 7 3 0 Teleostei 17 4 27 1 4 2 11 2 12 0 PacHi c 2 116 7 4 9 1 herri n9 20 Northern 50 6 69 3 57 9 78 9 anchovy 25 6 Chinook 17 salmon Whitebait smelt 13 8 9 7 104 15 6 Rock fi shes 14 3 18 5 3

4 30

174 PACIFIC HERRING ADJUSTED SAMPLE SIZE X 14 S D 8 31 LENGTH MM X 96 4 S D 22 9 WT OMS 12 IDO

w c u c z 80 0 CI 2 E bD r en 11 l z 0 IU 1 1 III 4U ro OJ U J EO o 0010 Ll 0 co lL r o 20 u 1

I U lL o

u c

L 20 w u

L ttl

0 z 40 o L g s

I

0 u OJ I y r L c fl J 0 U ro o al ro o tl 60 C r I U d lL 0 OJ ro U 9 r a 0 OJ 0 0 ro i r 0 J o 0 o 0 fl roEOCQ o u Vl1o LOOrouO u U OIU c o t710o o u O g b o l 5 6g 80 L u I QJ ro coC1Jc c U coo u J u u t lL u i 1

IDO 250 300 350 400 o 50 IDO 150 200

SI PHCIFIC tlERKING AOJUSTfO SRMPLE r 87 S U Wl OM JL 60 S Il ti7 I ENGltl MM j 81 lfl IOU

w u z 0 80 0 z l ttl a 60

ttl

z 0

I 40

J 0 lL r 0 u 20

LJ lL 0

I a 20 w x

ttl

Z 40 0 L 0

L L n U u a Ij 0 U x n 1 I l 0 f l 11 u l 0 U n u u j U I fm g 0 U l ll U U e L II U 1 L U Cl OJc OVl lL r L Q VI rol o a uuJ u J Cl U I if

IDO 120 140 160 180 200 0 20 40 60 80 100

CUMULATIVE FREQUENCY OF OCCURRENCE

in shallow sublittoral Fig 13 Prey spectrum of Pacific herring caught habitats of Sound upper and nearshore pelagic lower Puget broken down by percent numeric and gravimetric composition 1979 and prey frequency of occurrence 1978 Jl

Purse seine collections yielded 194 x 170 43 mm SL herring for

were the analysis of which 16 were empty Euphausiids primary prey for 85 of the total occurring in nearly 50 of stomachs and accounting were less in May 46 of prey biomass Table 8 Euphausiids important contributions in the total biomass than in February 96 due to greater calanoid 15 Dominant food May by brachyuran larvae 25 and copepods in both CPS and SPS although a greater variety items were generally the same in SPS of prey generally occurred 50 mm SL stomachs Many 63 of the 321 herring x 123 analyzed of from mid water trawl collections were empty and well digested x stage of contents after and digestion 2 2 suggesting regurgitation capture which diurnal feeding behavior Identifiable prey were primarily euphausiids occurred in 28 of stomachs with food and accounted for 98 of the prey biomass

Other baitfish

Two other baitfish species surf smelt and sand lance were captured however from beach by all gears utilized except hook and line only specimens Surf smelt were seine samples were analyzed for stomach contents captured in all months sampled except April and of 158 surf smelt x 110

were The contents of these fish 26 mm SL stomachs analyzed 44 empty were not well digested x digestion 4 4 although containing relatively little food x fullness 3 Surf smelt ate primarily pelagic prey particularly calanoids 24 of the overall prey biomass unidentifiable urochordates 25 carideans 10 and euphausiids 10 Fig 14 Cyclo

but were poids and larvaceans were not important prey gravimetrically important numerically The occurrence of small numbers of harpacticoids in a large proportion 61 of stomachs suggests the smelt are also epibenthic feeders Sand lance stomach samples were exclusively from CPS and were collected mostly from May through August Eighty one sand lance x 64 mm 17 SL items Calanoids were analyzed of which 49 had no identifiable prey lance in 71 of were by far the most important prey item of sand occurring sand lance stomachs and accounting for 87 of the prey biomass Fig 15

Other marine fish

Stomachs from additional fish species were analyzed as possible com

petitors or predators of juvenile salmon and herring Table 2 A brief description of their food habits by species follows IRI diagrams are pre 32

1979 Table 8 Food habits of Pacific herring from February and May purse seine collections in Puget Sound

February May SPS Parameter Overall CPS SPS Overall CPS

Predator characteristics No examined 75 34 41 119 40 79 1 8 No empty 22 21 1 9 181 153 Mean standard 1ength mm 185 175 188 120 4 0 4 4 3 8 Mean fullness 4 0 3 2 4 3 8 3 6 4 1 3 2 Mean digestion 3 0 3 6 2 Mean no prey categories stomach 19 2 0 19

Major prey items percent biomass 46 43 36 Euphausiacea 96 85 96 3 43 Ca1anoida 2 1 2 16 0 31 43 15 Brachyura 0 0 5 9 1 Total fish 1 9 0 J

SURF SMELT ADJUSTED SAMPLE SIZE 89 LENGTH MM X 110 2 S D 26 1 WT GMS X 13 46 5 0 11 38 100

w u z 80 a 0 z J al a 60

al

z 0

I 40

0 Q z 0 20 u

I U Q 0

I 5 20 ci W III x ci III

III al nl OJ 40 0 OJ z 0 0 u L I w L 0 nl a OJ 0 I u nl nl nl nl 0 60 nl nl nl c I s OJ 0 s Q 0 I nl co au ttJ 0 z U nl nl nl nl nl UlL nl L nl 0 0 0 OJ 0 0 00 QJ QJro c L U fD L 0 0 r E VI ttJco Cl u 0 0 III 0 a a L 0 s 00nl nl s u s 0 s 0 nl s nl U oo o a nl 0 U OJ s nl s sOJ OJ I 80 L OJ 0 g a U r a clLroV l U nl nl L Qj L co co s O OJ Q c u 0 I u co w aou UE

100 0 50 100 150 200 250 300 350

CUMULATIVE FREQUENCY OF OCCURRENCE

Fig 14 Prey spectrum of surf smelt caught in the shallow sublittoral habitats of Puget Sound broken down by percent numeric and gravimetric composition and prey frequency of occurrence Feb ruary August 1979 34

PACIFIC SAND LANCE ADJUSTED SAMPLE SIZE 41 LENGTH MM x 63 9 S O 16 7 WT OMS X 1 07 S O 90 100 w 80

z J lD a 60

lD

Z t

I 40

f t 0 x t u 20

I U 0 0

l t3 20 w Cll J 0

lD Cll 40 a z 0 t I Cll 0 I U I u 0 u 0 0 Cll 0 f 0 c 0 t 60 0 u a a sO 0 c 0 0 0 s x a s Cll s u a 0 t u 0 0 c Cll s U U I U I W

l 80 Ll 0

100 0 20 40 60 80 100 120 140 160 180 200

CUMULATIVE FRElJUENCY OF OCCURRENCE

in the shallow sub Fig 15 Prey spectrum of Pacific sand lance caught littoral habitats of Puget Sound broken down by percent num eric and gravimetric composition and prey frequency of occur rence February August 1979 j

sented in Appendix 2 for those species where at least 10 stomachs containing food were analyzed

Pink salmon Sixteen stomachs all but one with food from pink salmon

x 338 87 mm FL resident in puget Sound were collected by purse seine in May 1979 Mean abundance of organisms per stomach x 984 was the highest for any species analyzed from any habitat euphausiids and decapod larvae mostly cancridea were the primary prey consumed Appendix Fig 2 A Five pink salmon stomachs 4 with food were also collected from anglers in the Pacific Ocean anchovy and Cancer magister larvae were the primary prey

Cutthroat trout The stomach contents of 23 cutthroat trout x

356 82 mm FL were examined from beach seine collections and all but two contained identifiable prey items Cutthroat were mostly piscivorous as 74 of their overall prey biomass was fish Appendix Fig 2 B Sand lance was the major fish species eaten occurring in 43 of the stomachs and account ing for 60 of the prey biomass The major invertebrate prey was gammarid amphipods 16 biomass

Stee1head trout Twenty one 14 were empty stee1head trout

x 259 125 mm FL were collected from Puget Sound and 16 x 350 49 mm FL all but one with food from the Pacific Ocean In Puget

Sound their prey spectrum was comprised of a diverse array of crustaceans euphausiids gammarids insects and decapod larvae Appendix Fig 2 C

One herring accounted for 50 of the overall prey biomass With the exception of crab larvae fish was the only food item identified from the stomachs of Pacific Ocean stee1head anchovy 35 of the overall prey biomass chinook salmon 33 herring 2 and whitebait smelt 17 were the primary fish prey

Pacific cod Fourteen adult x 534 69 mm SL were analyzed 12 stomachs had identifiable food and 11 of the 14 cod were collec ted by anglers Cod we e mostly piscivorous as 56 of the prey biomass was fish Appendix Fig 2 D most of the remainder of the prey 31 were decapods

Pacific hake Fourteen 47 of the 30 hake x 425 34 mm SL analyzed from Puget Sound were empty Herring contributed the greatest pro 36

73 but occurred in only two stomachs portion of the prey biomass item in 93 of stomachs and Euphausiids were the other major food occurring of the biomass Appendix Fig accounting for 97 of prey numbers and 17 prey 2 E from catches Ten hake stomachs one was empty were also analyzed angler was 546 50 mm SL The in the Pacific Ocean the mean size of hake specimens Ocean hake was fish whitebait smelt and anchovy only prey eaten by Pacific

179 67 mm SL all with Pacific tomcod Sixteen Pacific tomcod x x fullness 5 4 with contents food were characterized by full stomachs x 4 4 Polychaetes 50 of that were relatively undigested digestion 17 12 and fish 9 were major the total biomass cancridae gammarids 2 F prey eaten Appendix Fig

were mostly Walleye pollock Fifty six pollock 9 were empty analyzed seine and in SPS adults x 349 135 mm SL from p rse angler samples biomass 2 G Gravimetrically the major prey was fish 92 Appendix Fig ca1anoids cancridae and hyperiids whereas invertebrate prey most1 am arids of the diet numerically and in terms of frequency were more important components

of occurrence

Sebastes stom Rockfish Copper black and yellowtail rockfish spp fishermen in Sound and the achs were collected primari1 from sports Puget 1 were all Pacific Ocean The 21 stomachs 14 plack 6 copper yellowtail had identifiable Fish was the from adults and all but four blacks prey 50 to 100 of the biomass of each most important prey item comprising prey were identified from rockfish stomachs species Shiner perch and sculpins those collected in the Pacific collected in puget Sound nd ancpovy from

Ocean

seine had eaten Cabezon One adult cabezon stomach collected by beach

algae and one juvenile C ncer gracilis

seine collection all American shad Six adult shad from the May purse omilss had nci i ds 92 bi had food in thei r stoachs and consumed pri pally euphausi

d k d 32 prey bi omass calanoi Th e i sti c le Cyc1opoi copepods JI

food copepods 32 and fish eggs 24 made up the bulk of the consumed by 7 adult stickleback

collected from Spiny dogfish Three spiny dogfish stomachs by anglers the Pacific Ocean were empty

17 were ac orn sculpin Fifteen staghorn sculpin empty

Sound 177 28 mm St analyzed from beach seine collections in puget averaged for 67 of the Fish herring shiner perch and sand lance accounted prey biomass of these staghorn scu1pins Appendix Fig 2 H

Great sculpin One great sculpin had eaten algae 8 biomass one Hemigrapsus nudus 21 and two unidentified fish 71

Starry flounder The stomachs of three starry flounder caught by anglers in the Pacific Ocean were empty

Butter sole One butter sole from the Pacific Ocean had 4 gammarids

and one Crangon sp

Predation on Juvenile Salmon

Predation especially by other sa1monids has been suggested as a prin salmon As shown cipal cause of marine and estuarine mortality of juvenile below four species of fish all sa1monids were identified by this study as predators on juvenile salmon

Percentage of predators Mean number Salmonid Month area containing salmon per salmon Predator prey of occurence predato

1 Coho juveniles Chum May SPS 7 0 Coho subadults Chinook April CPS 11 0 9 7 Coho subadu1ts Chi rook August CPS 11 0 Cutthroat trout Chum April SPS 50 0 5 Steelhead trout Chinook June Pacific Ocean 20 10 Steel head trout Chinook July Pacific Ocean 10 0 1 Chinook subadu1ts Chinook June Pacific Ocean 10 0 1 38

While most of these rates are relatively low their implication is un certain because of the lack of data on predator standing stocks If predator be standing stocks are very large low predation rates may significant

Competitive Interactions the Competition is essentially the demand by two or more individuals of is or same or different species for a common resource that actually potenti interactions ally limiting This study was not designed to assess intraspecific stocks of and without detailed data on resource vailability e g standing

herring euphausiids and other prey conclusions concerning interspecific However when we obtain competition based on diet similarity are speculative between sufficient data on nearshore pelagic zooplankton competition zooplank this tivorous species e g herring and chum juveniles for particular prey diet between resource can be investigated Comparisons of similarity species area month habitat were made with as much specificity e g predator size

It was assumed that the more similar as possible to minimize variability diets were the greater the likelihood of competition in Juvenile chinook and coho salmon diets generally were similar sublit crustaceans toral and nearshore pelagic habitats emphasizing somewhat larger

diets were different from such as brachyuran crab larvae Juvenile chum quite fewer those of juvenile chinook and coho They tended to consume larger prey

and instead ate smaller prey such s cyclopoid and harpacticoid copepods be Differences between the diet of chum and those of chinook and coho may

in these habi ats were related to predator and prey sizes Chum 9ccurring the smaller than the chinook and coho and thus may have been unable to eat diets and coho Chinook and larger food items characterizing the of chinook it to an ration coho on the other hand could find difficult obtain adequate nd by eating small prey such as calanoids cyclopoids The diets of juvenile herring and surf smelt were more intermediate both smaller between chum and chinook and coho bei g characterized by prey crab larvae Sand lance such as copepods and larger prey such as brachyuran and which ate almost exclusively calanoids could compete with chum herring

surf smelt since calanoids were important prey of all three species seine we were In the more offshore pelagic habitats sampled by purse

mm SL chinook 200 mm FL only able to compare larger herring 150 were small and coho 200 mm FL because sample sizes of other species too this were similar Herring chinook and coho food habits in habitat enerally

was decapod insofar as prey composition concerned euphausiids gammarids 39

Diets of the larvae and fish mostly herring were their primary prey of these items particularly fish three species differed in the proportion least chinook less so to coho and to herring fish were most important to most similar coho ate a greater Herring and coho diets were the although in As a result herring and coho variety of crustaceans than did herring resources It is likely that chinook this habitat may compete for some prey Sound would with other in the offshore pelagic habitats of puget compete rockfish piscivorous species such as pollock hake and

Pelagic Prey Selectivity was dominated by The nearshore surface pelagic zooplankton numerically ca1anoid mostly brachyuran crab larvae especially Cancer sp copepods 9 larvae hydrozoans Ca1anus sp and barnacle larvae Table brachyuran and ca1anoid copepods were the dominant zoop1ankters gravimetrically chinook and coho diets in some months Insects an important component of Because occur directly on the surface were rare in the zooplankton they these Not surprisingly our plankton nets probably did not sample organisms few epibenthic crustaceans e g harpacticoids and gammarids important 3 collected The density numbers m and prey items of some fish were 3 were in and biomass g m of surface zooplankton greatest April May and larvae June due primarily to ca1anoids in April and ca1anoids brachyuran In the and biomass in both May and June Fig 16 17 general density 250 m from shore of zooplankton were greater in the offshore transects 16 17 than in the inshore transects 25 50 m from shore Fig concurrent Of the species analyzed from beach seine samples collected most similar to surface with zooplankton samples the diet of herring was the pelagic zooplankton The primary difference was in the consumption by herring and that were of some organisms especially harpacticoid cyc10poid copepods of chum salmon and not prominent in zooplankton samples The prey spectra the Chum surf smelt were also generally similar to zooplankton composition than was salmon and surf smelt consumed a greater proportion of 1arvacea at times consumed represented in the zooplankton and as with herring they ate brachyuran some epibenthic organisms Coho salmon juveniles primarily in sam crab larvae in a higher proportion than was represented zooplankton in ples Other abundant pelagic zooplankters were poorly represented least similar to the surface juvenile coho diets Chinook diets were the that were not well zooplankton samples as they largely consumed organisms e amphipods and insects represented in the zooplankton samples g gammarid 40

Table 9 Percent numeric and gravimetric composition of nearshore surface pelagic zooplankton from Puget Sound February September 1979

Percent numeric Percent gravimetric Category composition composition

Cnidaria 01 01 I Hydrozoa 7 16 22 61 Scyphozoa 01 07 Anthozoa 01 03 C tenophora 44 3 80 Nematoda 01 01 Po1ychaeta 13 55 Gastropoda 65 07 Cephalopoda 01 01 Arachnida 01 01 Crustacea 01 01 C1adocera 10 01 Myodocopa 06 08 Copepoda 01 01 Ca1anoida 26 46 17 94 Harpacticoida 05 01 Cyc1opoi da 05 01 Monstri11oi da 01 01 Ca1igoida 01 01 Ba1anomorpha 20 32 175 Mysidacea 46 45 Cumacea 10 06 Isopoda 01 01 Gammaridea 15 35 Hyperi idea 59 45 Caprell idea 26 14 Euphausiacea 4 05 2 78 Penaeidea 01 01 Caridea 3 78 2 00 Anomura 125 1 33 Brachyura 27 68 39 35 Insecta 02 01 Chaetognatha 154 3 83 Larvacea 2 57 24 Te1eostei 2 15 2 09 YJ

800 Inshore Offshore CPS

700

600 I E

III f 500 QJ i 0 E

c 400

300 III c QJ a

200

t 100 I

JAN FEB MAR APR MAY JUN JUL AUG SEP

800 Inshore Offshore SPS

700

600

I E

III 500

QJ 0 E

c 400

300 III c QJ Cl

200

II

100

JAN FEB MAR APR MAY JUN JUL AUG SEP

Fig 16 Density numbers m3 of nearshore surface pelagic zooplankton from inshore N3 4m in depth and offshore N20 25m in depth tows in CPS upper and SPS lower February September 1979 42

0900 Inshore Offshore CPS

1800

I 0700

V i E 0600

III E rtl S 0500 0

III 0400 III rtl E 0 0300 ca

0200

0100

IAN FW MAR APR MAY JUN JUL AUG SEP

0900 Inshore offshore SPS

0800

0700

V 0600 E

III E rtl 0500 S O

III 0400 III rtl E 0 0300

ca

II 00

0 00 f

JAN FEB MAR APR MAY JUN JUL AUG SEF

Fig 17 Standing crop gr m3 of nearshore surface pelagic zooplankton from inshore N3 4m in depth and offshore 20 25m in depth tows in CPS upper and SPS lower February September 1979 43

ACKNOWLEDGEMENTS

Analyses of Puget Sound fish stomachs and zooplankton were performed Buechner by Jeffery Cordell Douglas Milward Linda Matheson and Hannalee of the University of Washington Fisheries Research Institute under a subcontract Charles Simenstad and William Kinney supervised the analyses and provided

valuable advice project scope data analysis and interpretation I I concerning of results Collection and analysis of stomachs of Pacific Ocean salmon were performed under subcontract by Sandy Lipovsky Her zeal and analytical expertise greatly enhanced dividends from this part of the study

The assistance of many Washington Department of Fisheries personnel in Carr obtaining samples is gratefully acknowledged Eugene Sanborn and Mark of the Research and Development Division Lonnie Crumley of the Harvest Management

Division and Robert Trumble and Dan Penttila of the Marine Fish Program were particularly helpful Richard O Conner offered invaluable assistance in analyz ing the data The contributions of the skippers and crews of the KATIE C REBEL and

R V MALKA are gratefully acknowledged Financial support for this research was provided by grants from the Pacific Northwest Regional Commission No 10890606 and the National Marine Fisheries Service under the Anadromous Fish Conservation Act P L 89 304 44

LITERATURE CITED

Bax N J E O Sa10 B P Snyder C A Simensta and W J Kinney 1978 Sa1monid outmigration studies in Hood Canal Final Report J Phase III Univ of Wash Fish Res Inst FRI UW 7819 128 p

S J Olsen E W Sanborn 1978 Water I Cardwell R D M I Carr and I in quality and biotic characteristics of Birch Bay Village Marina 1977 October 1 1976 to December 31 1977 Wash Dept Fish Prog Rept No 69 90 p

Cross J N K L Fresh B S Miller C A Simenstad S N Steinfort and J L Fegley 1978 Nearshore fish and macroinvertebrate assemblages along the Strait of Juan de Fuca including food habits of common near Tech Memo ERL MESA 32 shore fish Report of two years of sampling NOAA 188 p

Fresh K L D Rabin C Simenstad E O Sa10 K Garrison and L Matheson 1979 Fish ecology studies in the Nisqua11y Reach area of southern Puget FRI Sound Washington Final Report Univ of Wash Fish Res Inst UW 7904 229 p

Fresh K L and R D Cardwell 1979 Salmon herring predator competitor interactions project Unpub1 Contract Rept to PNRC 53 p

Gonso1us R T 1978 The status of coho and recommendations for managing the production harvest and escapement of wild and hatchery reared stocks Oregon Dept Fish Wi1d1 Columbia Region Portland Oregon 59 p

of salmon in Strait Healey M C 1976 Herring in the diets Pacific Georgia Fish Res Bd Can Manu Rept No 1382 39 p

of Healey M C 1978 The distribution abundance and feeding ecology juvenile Pacific salmon in Georgia Strait British Columbia Fish II Mar Serv Tech Rep rt No 788 49 p

in the II Healey M C 1979 Detritus and juvenile salmon production Nanaimo I Production and feeding rates of juvenile chum salmon ketal J Fish Res Bd Can 36 488 496 III Oncorhynchus

Johnson F C 1974 Hatch A model of fish hatchery analysis National Bureau of Standards Applied Mathematics Division Institute for Basic Standards Washington D C Rept No NMBSIR 74 521 52 p plus Appendices

Johnson F C 1977 Salmon enhancement analysis National Bureau of Standards Institute for Basic Standards Washington D C Unpuhl 39 Rept to Wash Dept Fish Olympia Washington p plus Appendices 45

of Sound Kirkness W 1948 Food of the chinook and silver salmon Puget 1948 Wash Dept Fish Annual Rept pp 28 31

Merkel T J 1957 Food habits of king salmon Oncorhynchus tshawytscha Wa1baum in the vicinity of San Francisco Calif Fish Game 43 249 270

B S C A Simenstad L L Moulton K L Fresh F C Funk I Miller W A Karp and S F Borton 1977 Puget Sound baseline program 1974 June 1977 Univ near shore fish survey Final Rept July of Wash Fish Res Inst FRI UW 7710 220 p

1971 of a1ba Pinkas L M S Oliphant and I L K Iverson Food habits Calif Fish core b1uefin and bonito in California waters Dept Bull 152 1 105

Prakash A 1962 Seasonal changes in feeding of coho and chinook spring Bd Can salmon in southern British Columbia waters J Fish Res 19 851 866

Silliman R P 1941 Fluctuations in the diet of chinook and silver related to the Oncorhynchus tshawytscha and O kisutch of Washington as troll catch of salmon Copeia2 80 87

Simenstad C A and W Kinney 1978 Trophic relationships of outmigrating chum salmon in Hood Canal Washington 1977 Final Rept Univ of Wash Res Inst FRI 7715 75 p t Fish UW

Simenstad C A W J Kinney S S Parker E O Sa10 J R Cordell and H Buechner 1980 Prey community structure and trophic ecology of out A migrating juvenile chum and pink salmon in Hood Canal Washington 1979 Final Univ of Wash synthesis of three years studies 1977 Rept Fish Res Inst FRI UW 8026 113 p

still lots of Terry C 1977 Stomach analysis methodology questions eds Pages 87 92 In C A Simenstad and S J Lipovsky Proceedings First PacifiCNorthwest Technical Workshop on Fish Food Habits Studies Washington Sea Grant WDG W077 2

Walters C J R Hilborn R M Peterman and M J Staley 1978 Model J for examing early ocean limitation of Pacific salmon production Fish Res Bd Can 35 1303 1315 46

APPENDIX 1

Scientific Classification of Invertebrates Recorded 4 Contents From Zooplankton Samples and Stomach I II 47

Appendix 1 Taxonomic list of invertebrates identified from zooplankton samples and stomach contents

Scientific Classification Common Name

Cnidaria Coelenterates 6 Phylum i Class Hydrozoa Genus Velella purple sailor I Class Scyphozoa Class Anthozoa Phylum Ctenophora Round worms Phylum Nematoda Phylum Class Gastropoda Order Mesogastropoda Snail s Genus Littorina Order Thecosomata Sea butterfl i es Class Bivalvia Clams Class Cephalopoda Subclass Coleoidea Genus Loligo Genus Octopus worms Phylum Annelida Segmented Class Polychaeta Subclass Errantia Fami i dae I ly Syll Genus Autolytus r Family Nerei dae Genus Platynereis Subclass Sedentaria Family Spionidae Family Ophe1iidae Phylum Arthropoda Class Arachnida Spiders mites Order Araneae Spiders Class Crustacea Subclass Branchiopoda Order C1adocera Water fleas Genus Podon Subclass Ostracoda or seed Order Myodocopa Subclass Copepoda Copepods Order Calanoida Calanoids Genus Calanus Genus Euca1anus Genus Paracalanus Genus Aetidius Genus Metridia Genus Epilabidocera Genus Acartia Genus Candacia 48

Order Harpacticoida Harpacticoids Order Cyclopoida Genus Oncaea Genus Coricaeus Order Monstrilloida Order Caligoida I Subclass Cirripedia Barnacles Suborder Balanomorpha Sessile barnacles Genus Balanus Subclass Malacostraca Order Mysidacea Family Mysi dae Opossum shrimp Genus Boreomysis Order Cumacea Genus Cumella Order Tanaidacea Order Isopoda Suborder Epicaridea Suborder Flabellifera Order Amphipoda Suborder Hyperiidea Genus Parathemisto Genus Hyperra fleas Suborder Gammaridea Sand J Genus Calliopius Genus Corophium Genus sogammarus Genus Paraphoxus Genus Accedomoerra Suborder Caprellidea Genus Caprella Superorder Eucaridia Order Euphausiacea Family Euphausiidae Genus Euphausia Genus Thysanoessa Order Decapoda Suborder Natantia crabs Section Penaeidea Shrimps Section Pleocyemata Caridea Family Hippolytidae Genus Heptacarpus Fami ly PandaITdae Genus Pandalus Genus Pandalopsis Family Crangonidae Genus Crangon Sand shrimps Section Anomura Crabs Family Callianassidae Genus Callianassia 4q

Family Paguridae Hermit crabs Genus pagurus Section Brachyura True crabs Infrasubsection Brachyrhyncha Family Cancridae Cancer crab Genus Cancer I Pinnotheridae Pea crabs I Family Decorator crabs I Infrasubsection Oxyrhyncha Fami ly Maj i dae Insects Class Insecta i es Order Ephemeroptera Mayfl I Termites Order Isoptera Stone fl i es Order Plecoptera Lice Order Psocoptera Order Homoptera Aphids Family Psyllidae Alder f1 i es Order Neuroptera True f1 i es Order Di ptera Family Ants bees Order Hymenoptera wasps Phylum Chaetognatha Genus Sagitta Arrow worms Phylum Chordata Subphylum Urochordata Class Larvacea Genus Oikopleura Tunicates J 50

I 1 APPENDIX 2

Prey Spectra of Other Marine Fish Species From puget Sound

I

j J

PINK SALMON ADJUSTED SAMPLE SIZE 16 LENGTH MM X 337 6 5 0 87 0 WT GMS X 511 81 5 0 164 84 100 r UJ i 80 I

60

CD

40

20 u

U lL 0 LJ

20 UJ 0 x 0 Co

CD u OJ 40 OJ Cl 0 OJ U I OJ OJ OJ 0 c E 0 OJ 0 t 0 0 u l C J l 0 c 60 u c OJ E u c Co u Co 0 OJ 5i l l C x c u x 0 t r lJ u

80 u lL

100 o 50 100 150 200 250 300 350 400

CUMULATIVE FREQUENCY OF OCCURRENCE

in Sound Appendix Fig 2 A Prey spectrum of pink salmon caught Auget broken down by percent numeric and gravimetric composition and prey frequency of occurrence Feb ruary June 1979 52

t

J

CUTTHROAT TROUT AoJUSTEO SAMPLE SIZE 21 LFNrHH MM 3 8 S D 87 1 WT GI1S X 3fl3 l3 S n 2mL47 lUll X

w u z a 80 a z l m a 60

m

z 0

I 40

f 0 a c 0 20 u

I U a 0 LJ I

l 1 tS 20 W 3 Vl QJ

lD ta au 04 Z 40 s or 0 0 a QJ QJ 0 aa I c o f uu 0 60 I I Vl Vl QJ a I Cl c Vl I cQJ E a 0 QJ QJ QJ E EO QJ u QJ 0 u u 00 0 QJ U QJ a c E 60 Vl c QJ u O c 0 u u a en QJQJ 0 u u U 0 QJ a aaE a E 0 c OJ 0 c I u u I UU V 100 o 20 40 60 80 100 120 140 160 180 200

CUMULATIVE FREQUENCY OF OCCURRENCE

Appendix Fig 2 B Prey spectrum of cutthroat trout caught in Puget Sound broken down by percent numeric and gravi metric composition and prey frequency of occurrence February August 1979 1 51

RAINBOW TROUT ADJUSTED SAMPLE SIZE 18 LENOTH MM X 259 1 5 0 124 8 WT GMs X 351 00 5 0 761 100 2 1 I

I eo

60 I0 lD

40 18

20

0

e 20

0 lD 40 0 0 0

U

1 cu 60 U I cu cu cu u cu 0 0 CU 0 0 Vl 0 0 cu 0 0 C J 0 0 uo 00 0 0 J O I u oS cu o c 0 U 0 r ow c o 80 J 8cu J U o cu cu V ut 2 ocel r

100 0 50 100 150 200 250 300 350

ClI1ULATIVE FREQUENCY OF OCCURRENCE

Appendix Fig 2 C Prey spectrum of steel head caught in Puget Sound broken down by percent numeric and gravimetric composition and prey frequency of oc currence February August 1979

I 54

PACIFIC COD ADJUSTED SAMPLE SIZE 12 LENGTH MM X 533 6 5 0 69 2 WT GMS X 1725 87 S 0 a37 89 100 r l

80

I 60 CD

Z o

I 40

en o

o 20 u

I U l o

I lS 20

CD 40 I C1l li J 0 Ul J a I 0 0 C1l C1l u Gi C1l 0 J e C1l 60 J u s Ul C1l l e a s r taOQJCU u u s 0 0 0 s e Ul tn C1l Ul 0 e OOlu I e u u ci a I 80 u l

100 o 50 O 50 200 250 300

ct frJ F 9 Y OF OCCURRENCE

Sound Appendix Fig 2 D Prey sp trum of Pacific cod caught in Puget brok n 9q Dqy er ent numeric and gravimetric com P t19n pq pr y frequency of occurrence February JU r 979

i 55

r PACIFIC HAKE ADJUSTED SAMPLE SIZE 16 S D WT GMS 456 4 S D I LENOTH MM X 424 9 34 1 X 128 4 100

W j Z a 80 Cl z

co a 60

co

z I

I 40

co I CL I I j 20

I j CL o I

I l3 20 w t

co 40 z I

I

co I 60 CL VI OJ t 0 u OJ I j u Qj E VI I OJ l c I 80 OJ u en U s s C 0 0 CL VI en OJ 0 l c LU u o 100 o 20 40 60 80 100 120 140

CUMULATIVE FREQUENCY OF OCCURRENCE

Appendix Fig 2 E Prey spectrum of Pacific hake caught in Puget Sound broken down by percent numeric and gravimetric comp osition and prey frequency of occurrence February Ausust 1979 56

PACIFIC TOMCOO AOJUSTSAMPl f SILl If

LENGTII r r X 175 1 S O 58 2 T GMS X 62 63 S O 60 15 100

W LJ z 80 a Cl z l In a 60 In

z o

I 40

J o a 1 o LJ 20

I LJ a o y J Lp

c I u ei c 20 r W 3 C U In rcl

z 40 co J o I rcl ClJ I 0 0 a J rcl rcl X o 60 rcl u rclQ rcl Q Q rcl rcl U Q Cl rcl o Q rcl 0 rcl 4 I LJ 0 Q Q rcl Q Q Q E 0 rcl U 0 rcl Ill Q III rcl J I 80 J 4i 0 4i u 0 QJ C U LJ u E 0 QJ roc 0 0 a c 0 a III rcl u 00E Q rcl rcl c rcl J 0 4i l W o w L w a I a

0 100 o 50 190 150 200 250 300 350

C T VE F QU NCY OF OCCURRENCE

Appendix Fig 2 F Prey sp ctrum Plf Paci fi c tomcod caught in PUfJet Sound bro t rll 001 11I 0Y p er cerlt numeri c and gravimetri c comp os i qOIl 1II d pllIeY frequency of occurrence February I JugWt 1 917 9 rs7

WRLLEYE POLLOCK ADJUSTED SAMPLE SIZE Sl 135 0 WT GMS X 415 51 5 0 434 49 LENGTH MM i 349 1 5 0 100

11 80

I 60 ID

I 40

o 20 u

I U a o

l

e 20

ID

40 fCl 0 0 a l 1 fCl V J fCllJ VI fCl f 60 lJ fCl J Cl 0 fCl fCl V J lJ fCl l lJ fCl fCl lJ fCl 0 lJ 0 lJ c OJ 0 IT C 0 VI lJ UOl1 t ra c r I o JC c L fCl V O CUlOs t 80 fCl v lJ s 0 L s VlttlUCO VI c a a lJ lJ 1 Co C fCl fCl c UlJJ Cl u U I LU a

100 200 250 0 50 100 lS0

CUMULATIVE FREQUENCY OF OCCURRENCE

Appendix Fig 2 G Prey spectrum of walleye pollock caught in Puget Sound broken down by percent numeric and gravimetric composition and prey frequency of occurrence Feb ruary August 1979

4

i f 58

1 I

31

PRC STRGHDRN SCULPN RDJUSTED SRMPLE SIZE 15 64 c LENGTH MM X 177 1 5 0 27 6 WT GM5 X 140 73 5 0 100

w u z IT 80 o z J lD IT 60

J

1

f J rL

cO U

U lL o

i

l I rs 20 W 3

Ql 0 eD Ql f 0 o z 40 u 0 o Ql au I u 0 e r r u VI if or VI Ql OJ ton COi r 1J cu t 60 Cl E QlQla lL U Ql EO Ql 0 e s 0 4 0S ai nsO ou c E 0 54 0 u VI 0 Qj C en o OJ cu U J CLQ UO 0 EU CD Ql O U o I 80 CQ rOrtJ c Qj 2 U uu a 0 q c uco Q w f

L L 1 1 OD IJn so 100 150

LUMULHIIVE FREQUlNCY O OlCUkktNlL

in Appendix Fig 2 H Prey spectrum of Pa ific staghorn sculpin caught in PU9 t ouqd broken down by percent numeric and grqvimetric compostion and prey frequency of occur r nce February August 1979