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Supplemental Materials
Rarefaction Curves
We plotted rarefaction curves for each fish predator in 2010 and 2011, adding stomachs in
random order and using 1000 permutations to determine 95% confidence intervals for the curve.
Comparisons of Individual Predator Diets Using Different Metrics
Number of Prey Consumed vs. Biomass
Overall patterns in diet composition were similar for rockfish and halibut regardless of whether
we used number consumed or biomass as a metric (Figs. S2 and S3). Salmon diet composition
was different depending on the metric used, with fish prey de-emphasized when using number
consumed (Fig. S4).
Number of Prey Consumed vs. Frequency of Occurrence
Rockfish diets (55 taxa) differed in number of prey consumed between 2010 and 2011 (MRPP,
Count: A = 0.0465, p = 0.006; Occurrence: A = 0.1675, p < 0.0001). The strength of the
difference between years was greater for the frequency of occurrence metric, suggesting that the
difference may be driven by prey categories consumed frequently but in relatively small
numbers. Several prey categories appeared to be driving the differences between years. Fish
constituted a greater percentage of the black rockfish diets in the 2010, although the 2011 diets
had a more diverse invertebrate component (Table 1).
Common murre diets differed in number of prey consumed between 2010 and 2011, but not in
frequency of occurrence (MRPP, Count: A = 0.175, p = 0.0007, Occurrence: A = 0.025, p =
2
0.244). The lack of difference in frequency of occurrence between years is likely caused by
relatively few prey categories used in the analysis (n= 10), and relatively large number of
samples collected during each sampling week (n = 11-277), resulting in a diet matrix where most
prey categories were present in each week of sampling.
Comparisons of Predator length, prey length and nMDS axes
We plotted scatterplots of predator length and prey length against both nMDS axes for each year
of the study.
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Table S1. Taxonomic identity of prey species grouped to more general prey categories for analysis, shown by predator. If there
were no instances of a prey category within the diet of a predator, that entry has been left blank.
Predator
Prey Category
Small Zooplankton
Krill
Pelagic Pteropod
Gastropods
Gelatinous
Zooplankton
Mysids
Cancer crabs
Other Crab larvae
Black rockfish
Isopoda
Cumacea
Amphipoda
Gammaridae
Hyperiidae
Euphausia pacifica
Thysanoessa spinifera
Chinook salmon
Limacina helicina
Anoplopoma fimbria
Mysidae
Neomysis rayii
CANCER
Cancer spp.
CANCER
Cancer magister
MAGISTER
Shrimps
Other invertebrates
Phrixocephalus cinncinatus
LOLIGO
Loligo opalescens
OPALESCENS
Squids and Octopus
Herring, Sardine, and
Shad
Hake and cods
Smelts
Clupea pallasi
Merluccius productus
Allosmerus elongatus
Sebastes spp.
Clupea pallasi
Alosa sapidissina
Sardinops sagax
Merluccius productus
Allosmerus elongatus
Sebastes spp.
Rockfishes
Pacific sandlance
Flatfishes
Other fishes
Other
Ammodytes hexapterus
Pleuronectiformes
Citharichthys spp.
Citharichthys sordidus
Lepidopsetta bilineata
Parophrys vetulus
Psettichthys melanostictus
Cottidae
Hemilepidotus spinosus
Liparidae
Hexagrammidae
Ophiodon elongatus
Agonidae
Stellerina xyosterna
Engraulis mordax
Plantae
Cancer spp.
Cancer productus
Acantholithodes hispidus
Chorilia longipes
Lopholithodes foraminatus
Pandalus danae
Pandalus jordani
Pandalus platyceros
Shelf/Slope crabs
Caridea
Crangonidae
Crangon alaskensis
Crangon dalli
Crangon stylirostris
Pandalidae
Pandalus danae
Nemertea
Polychaeta
Loligo opalescens
Common Murre
Euphausia pacifica
Thysanoessa spinifera
Limacina helicina
Emerita analoga
Homalopoma baculum
Olivella biplicata
Cnideria
Salpa
Mysidae
Alienacanthomysis macropsis
Archaeomysis grebnitzkii
Exacanthomysis davisi
Holmesimysis sculpta
Neomysis mercedis
Neomysis rayii
Xenacanthomysis pseudomacropsis
Cancer spp.
Cancer magister
Diogenidae
Porcellanidae
Pachycheles pubescens
Petrolisthes eriomerus
Grapsidae
Hemigrapsus oregonensis
Paguridae
Pagurus spp.
Pagurus ochotensis
Pinnotheridae
Fabia subquadrata
Pacific halibut
GAMMARIDAE
Gammaridae
Ammodytes hexapterus
Pleuronectiformes
Engraulis mordax
Rossia pacifica
Loligo opalescens
Enteroctopus dofleini
Clupea pallasi
Alosa sapidissina
Sardinops sagax
Merluccius productus
Sebastes spp.
Sebastes helvomaculatus
Sebastes melanops
Sebastes zacentrus
Sebastolobus alascanus
Pleuronectiformes
Citharichthys spp.
Citharichthys sordidus
Parophrys vetulus
Atheresthes stomias
Eopsetta exilis
Glyptocephalus zachirus
Lyopsetta exilis
Microstomus pacificus
Ophiodon elongatus
Agonopsis vulsa
Hydrolagus colliei
Lampetra tridentata
Plastic
Loligo opalescens
Clupeidae
Gadiformes
Allosmerus elongatus
Sebastes spp.
Ammodytes hexapterus
Pleuronectiformes
Cottidae
Engraulis mordax
Onchorhynchus spp.
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Supplementary Figure Captions
Figure S1. Rarefaction curves of black rockfish, Chinook salmon and Pacific halibut diets in
2010 and 2011. The dark blue line represents the rarefaction curve for the number of prey
species identified, and the lighter blue shaded area shows 95% confidence intervals.
Figure S2. Black rockfish diets, shown as percent of total biomass (S2a) and number consumed
(S2b).
Figure S3. Pacific halibut diets, shown as proportion of total biomass (S3a) and number
consumed (S3b).
Figures S4. Chinook salmon diets, shown as proportion of total biomass (S4a) and number
consumed (S4b). As in Table 1, one outlier sample was excluded from 2011 in these
unstandardized data, but was retained in the statistical analyses.
Figure S5. Scatterplots of mean predator length for each sample unit of the fish predator
ordinations and their corresponding nMDS scores for Axis 1 and 2.
Figure S6. Scatterplots of mean prey length for each sample unit of the fish predator ordinations
and their corresponding nMDS scores for Axis 1 and 2.
Figure S7. Scatterplots of mean predator length for each sample unit of the all predator
ordinations and their corresponding nMDS scores for Axis 1 and 2.
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Figure S8. Scatterplots of mean prey length for each sample unit of the all predator ordinations
and their corresponding nMDS scores for Axis 1 and 2.