Dietary composition of four stocks of pacific harbor seal (phoca vitulina richardii) in the northern california current large marine ecosystem as synthesized from historical data, 1931-2013.
The northern CCLME's coastal marine geography is defined by numerous bays and river inlets, as well as rocky volcanic reefs, rocky intertidal areas, and sandy shore-bottom zones. The northern CCLME is comprised of 4 genetically- and ecologically-distinct stocks of Pacific Harbor Seals: (1) the Oregon-Washington Coastal; (2) the Hood Canal; (3) the Southern Puget Sound; and (4) the Washington Northern Inland Waters stocks (Lamont and others 1996; Dishman 2011; Carretta and others 2015). The dividing northern extent of the Washington Inland Waters stock is the Salish Sea (Burg and others 1999). The Washington State region includes both estuarine and coastal habitat, as well as the 2642 [km.sup.2] Puget Sound. The Puget Sound, including the ecologically rich San Juan Islands, creates a unique inland marine ecosystem for Harbor Seals and their prey. It is home to 3 of the 4 genetically-distinct stocks Harbor Seal in the northern CCLME, including the Hood Canal stock, Southern Puget Sound stock, and Washington Northern Inland Waters (Puget Sound) stock (Carretta and others 2015). Harbor Seals are the most abundant species of pinniped in the Puget Sound with estimates of >15,000 individuals (Lance and Jeffries 2006, 2009a). Harbor Seals residing in the San Juan Islands number over 4000 and reside at more than 150 haul-out locations (Lance and Jeffries 2009a). The Oregon Coast region of the northern CCLME has more than 22 bays, many of which are locations of Harbor Seal haul-out and breeding sites (Brown and others 2005). The Columbia River, the largest river in the Pacific Northwest, hosts numerous Harbor Seal haul-out sites, including Desdemona Sands, Baker Bay, South Jetty, Grays Bay, Green Island, Miller Sands, Welch Island, and Wallace Island (Beach and others 1985).
Since 1931, a number of potentially comparative, quantitative frequency-of-occurrence (% FO) prey studies for Pacific Harbor Seals have been conducted for the northern CCLME. However, this information has not been compiled on a larger comparative scale to assess breadth of diet of the Harbor Seal populations in this overall region. The northern CCLME would particularly benefit from a synthesis of information, as marine mammal-fisheries interactions, development of marine reserves, and other management issues are becoming increasingly prevalent. For example, management of local salmon and other commercially-important fish, and sturgeon populations are of concern as they relate to local pinniped predation and management (Beach and others 1985).
Due to dietary generalism, the diets of the Harbor Seal populations in the northern CCLME are likely much more diverse and cross-regional than has been presented in individual papers that have focused on Harbor Seal diets in this region. To exam this hypothesis, I conducted a review of pertinent literature regarding Harbor Seal foraging ecology in the northern CCLME. My review reveals the broad variability of Pacific Harbor Seal diet composition within the northern CCLME, between regions, stocks and season.
I conducted a literature review for all available sources published prior to and through May 2016 on a variety of academic search platforms, including Google Scholar ([C] Google, Inc.), Academic Search Premier ([C] Thomson Reuters), Google search engines, academic archives, and agency publications and reports. I utilized keywords relating to Harbor Seal diet in the Northern CCLME, including the terms 'Harbor Seal', 'Pacific Harbor Seal', 'Phoca vitulina richardii', 'foraging', 'fecal analysis', 'dietary', 'ecology', 'predation', 'diet', 'dive or diving', dietdietary composition', 'Washington', 'Oregon' 'Columbia River', 'Salish Sea', 'Northern California Current Large Marine Ecosystem (CCLME)', 'Puget Sound', and 'Pacific Northwest'. Papers, theses, and reports containing quantitative frequency of occurrence (% FO) data with known sample sizes specifically referring to the 4 stocks of Pacific Harbor Seals (Oregon-Washington Coastal, Hood Canal, Southern Puget Sound, and Washington Northern Inland Waters) in the northern CCLME, including the Salish Sea, Oregon, Washington, and the Columbia River were collected. Methodologies included otolith and multi-part hardparts analysis of prey in scat, and examination of stomach contents. Authors of unpublished or unavailable data were contacted for permission to include data. Non-peer reviewed sources were included if they contained data that were not represented through peer-reviewed sources. Because of the variety of different methods reviewed, data were not weighted or corrected for possible bias, but rather additively reported by % FO.
Results were compiled in Microsoft Excel ([C] Microsoft Corporation). All available data pertinent to the review were recorded: current common name, scientific name (genus and species), order, family, marine zonation (Froese and Pauly 2012), location collected, season, year, sample size, and % FO. All prey species were standardized to their currently accepted scientific classification and spelling. When papers classified prey items to their nearest taxonomic groupings (including class, order, family, genus, species, subphylum or group within a subphylum such as 'shrimp'), this grouping was retained as it was presented in the literature.
In order to obtain and compare total overall FO in all samples in = 13,088), the total number of occurrences in each study (S) was calculated:
S = (n * FO)/100
where n = the number of samples per study, and FO = the frequency of occurrence reported in the study. The total frequency of occurrence ([SIGMA]FO) per prey type for all studies combined was calculated as:
[SIGMA]FO = [SIGMA]S/N * 100
where [SIGMA]S = the total occurrences per species, and N = the total number of samples in all studies combined. If data occurred in more than 1 paper, it was only included once overall.
In some cases where prey were so prevalent that they led to a % FO >100% (for example demersal fishes in Oregon equaled 150% of FO, meaning that scats on average contained 1.5 various demersal fish species), a percent composition (C) value was calculated which represented the total percentage of all identifiable scat remains that consisted of a single group or species. Percent composition was calculated as:
C= [??]/N * 100
where [??] represents the total number of occurrences (identifiable remains) within that region, or overall. Percent composition is a proportion additive up to 100%. Most results in this paper are presented as % FO.
Prey data were divided between established stocks of Pacific Harbor Seals in the northern CCLME, and compared overall. Data were also compiled per location (Oregon, Washington, Columbia River), and by season. Seasonal values were grouped by winter-spring and summer-fall due to availability of data. Prevalence of salmon predation across regions was also reported.
The results of the review yielded 48 papers, reports, or theses that were directly relevant to Harbor Seal foraging for their descriptions of spatial behavior, quantitative and qualitative dietary analysis, or examination of potential fisheries interactions within the northern CCLME. Of the papers examined, 16 contained detailed, quantitative information on dietary composition primarily through FO in fecal hard-parts analysis (Table 1). Percent frequency of occurrence, or % FO, is the relative proportions of scat samples from all samples gathered that contain an identifiable type or species of prey. Two of the papers found, Brown (1980) and Lance and Jeffries (2007), contained data that were duplicated in other publications already being utilized and were not included in the quantitative analysis. The remaining sources (Table 2) included studies describing Harbor Seal behavior by visual observation or alternative measures of prey, captive dietary studies, spatial telemetry data, technical reports assessing and summarizing Harbor Seal predation on salmonids and other commercially-important fish species, a modeled feeding experiment, and genetic or alternative methods for identifying Harbor Seal dietary composition.
The summed utilizable sample size from all papers equaled 13,088, consisting of 12,993 scats and 95 stomachs with identifiable remains in inland and marine locations (Scheffer and Sperry 1931; Roffe and Mate 1984) (Fig. 1). All prey species reported in the reviewed literature and used in this analysis are listed in the appendix. Of the prey orders representing over 20% FO, gadiform fishes were the primary-occurring prey species (FO = 51.85%), followed by Clupeiformes (51.52%) and perciform fishes (23.72%). Families of fish present in more than 20% of scats included Clupeidae (44.05%), Merlucciidae (35.20%), and Salmonidae (20.47%). The species identified above 10% FO included North Pacific Hake (Merluccius productus), Pacific Herring (Clupea pallasii), and Shiner Perch (Cymatogaster aggregata) (Table 3). Prey species were primarily categorized as Demersal (52.56%), followed by Pelagic-Neretic (46.14%) and Pelagic-Oceanic (35.34%), suggesting a high rate of bottom foraging. Salmonids were present in 23.74% of scats overall, 3.73% of these being reported as juvenile fish. Almost all salmon reported were unidentified to the species level.
Oregon-Washington Coastal Stock
For Harbor Seals of the Oregon-Washington Coastal Stock, a total of 3960 scats or stomachs contained identifiable remains. Seals consumed primarily fish of the orders Pleuronectiformes (FO = 50.32%) and Clupeiformes (48.72%). The taxonomic families present in >20% of samples included Pleuronectidae (60.80%), Clupeidae (36.18%), Osmeridae (25.57%), and Cottidae (21.31%). Prey identified to the species level that occurred in >10% of scats included Pacific Herring, Pacific Staghorn Sculpin (Leptocottus armatus), Pacific Tomcod (Microgadus proximus), North Pacific Hake, Californian Anchovy (Engraulis mordax), Eulachon (T. pacificus), and Shiner Perch (Table 3).
Dietary composition from the Coastal stock consisted heavily of Demersal species (109.56% FO, or 53.15% composition). Pelagic-Neritic prey were also present in more than half of samples (56.73% FO). Coastal Harbor Seal diet consisted primarily of schooling fish species. There was also significant predation on Pacific Staghorn Sculpin, likely due to nearshore exploitation of a highly-available nearshore resource associated with salmonids (McCabe and others 1983). Salmonid species occurred in 9.99% of samples overall, most of which were not identified to species, and 2.88% of which were listed as juveniles.
Southern Puget Sound Stock
The Southern Puget Sound stock of Pacific Harbor Seals was the least-represented stock in the collated studies, with a total sample size of 101 scats collected at Gertrude Island in 1979 (Everitt and others 1981). Sixteen prey species or genera from 9 taxonomic families in 6 orders were identified. Gadiformes was the only prey order represented at >20% (61.38% FO). The family Merlucciidae was present in 56.16% of scats, and the species occurring in >10% of samples included North Pacific Hake (56.12%) and the Plainfin Midshipman (Porichthys notatus) (13.88%). Notably, no salmon remains were found in this region, which could be due to low sample size or geographic location.
Hood Canal Stock
The Hood Canal stock of Harbor Seals predominantly consumed gadiform fishes (64.59%), clupeiform fishes (50.89%), and salmoniform fishes (30.54% adult or unspecified, 3.74% juvenile) out of a total sample size of 7235 scats or stomachs. There were a total of 68 species or genera identified from 36 families and 22 orders, as well as 3 groups not specified to order classification (Cephalopoda, Gastropoda, Crustacea). Families of prey present in >20% of scats included Merlucciidae (53.56%), Clupeidae (46.52%), and Salmonidae (30.54%). Prey identified to the species level that composed >10% of the diet were North Pacific Hake (53.56% FO) and Pacific Herring (34.29%). Prey could be categorized as Pelagic-Oceanic (53.75%), Pelagic-Neritic (38.67%), and Demersal (20.77%). The Hood Canal Stock had the highest frequency of occurrence (34.27%) of salmonids in scat of all groups studied, with 2.86% being identified as juvenile fish. Lance and Jeffries (2009a) and Lance and others (2012) used multi-part analyses, and Scheffer and Sperry (1931) used stomach content analysis, which were potentially more successful at revealing salmon in the diet than did otolith-specific studies.
Northern Inland Waters Stock
The Northern Inland Waters Stock of Harbor Seals was represented by 1792 scat samples; 64.06% of these contained clupeiform fishes, 47.04% contained perciform fishes, 44.68% contained gadiform fishes, and 21.23% contained scorpaeniform fishes. There were 62 prey species or genera present from 43 families and 27 orders. The only families representing >20% FO were Clupeidae (53.71%) and Gadidae (38.39%). Prey identified to species at >10% FO were Pacific Herring, Pacific Sand Lance (Ammodytes hexapte rus), Shiner Perch, Alaska Pollock (Theragra chalcogramma), Californian Anchovy, and Three-spined Stickleback (Gasterosteus aculeatus) (Table 3). Prey occurring in >20% of scats were 56.66% Demersal, 55.7% Pelagic-Neritic, and 54.91% Benthopelagic.
Prey Composition by Season
A majority of samples (n = 10,026) were collected in summer and fall, most likely to coincide with seasonal salmonid abundance (Fig. 2). The remainder of samples were collected in winter and spring in = 2164), or throughout the year or not defined (n = 898). In summer-fall, of 32 orders of prey identified, Gadiformes predominated (54.26% FO), followed by Clupeiformes (51.3%), Salmoniformes (24.96%), and Perciformes (22.09%) (Table 4). Prey species were primarily Demersal (48.19% FO), Pelagic-Neritic (43.63%), or Pelagic-Oceanic (41.71%). In winterspring, of 28 orders identified, Clupeiformes was most prevalent in the diet (56.62% FO), followed by Gadiformes (48.74%), Perciformes (29.67%), Pleuronectiformes (24%), and Scorpaeniformes (22.42%). As in summer-fall, winter-spring prey occurring in >20% of scats were predominantly Demersal (63.57%), followed by Pelagic Neritic (55.97%), Benthopelagic (28.97%), and PelagicOceanic (20.34%). In winter-spring, salmonids were present in 13.4% of samples, and in summer-fall this percent more than doubled (28.49%).
Notable Results by State
Harbor Seal habitat in Oregon consists exclusively of coastal bays and riverine systems, and is considered part of the Oregon-Washington Coastal stock. The diet of Oregon seals consisted heavily of pleuronectid fish, which occurred in 92.84% of scats or stomachs analyzed with identifiable remains. Demersal fish consisted of 151.80% FO or 58.77% by composition, highlighting bottom foraging and consumption of pleuronectids. Prey by FO were identified as 37.89% Pelagic-Neritic. Out of 1211 samples, seals in Oregon consumed prey from 21 taxonomic orders, 35 families (29 of which were teleost fish), and 67 prey identified to the species or genus level. Seals in Oregon consumed 6 families of non-teleost prey, including Myxinidae, Octopodidae, Rajidae, Loliginidae, Cancridae, and Crangonidae. Salmonid fish occurred in 13.3% of scats collected. In one instance, at a collection site in the upper Alsea River (Wright and others 2007), salmonids were present in 50% of samples collected (n = 6).
Washington State's overall sample size (n = 10,070) was composed primarily of samples collected in non-coastal locations (86%), representing the Hood Canal, Northern Inland Waters, and Southern Puget Sound stocks (Fig. 3). The most predominant prey by % FO were gadiform fishes (58.18%). Consumption of salmonids was relatively high (27.8%), with 24.07% identified as adults or unspecified, and 3.73% as juveniles. Of 36 orders identified, only 18 were teleost fishes. Non-teleost prey consumed included cephalopods, crustaceans, rajiform fish, hagfish or lamprey, squaliform or elasmobranch fish (such as Pacific Spiny Dogfish, Squalus suckleyi), gastropods, polychaetes, bivalves, and instances of the consumption of mammals or birds (Luxa and Acevedo-Gutierrez 2013). It is likely that some of these were secondarily consumed, but were included in the analysis as they overall may have contributed to daily caloric intake. Consumption of an aquatic bird (Harlequin Duck, Histrionicus histrionicus) was also visually observed by Tallman and others (2004) in the San Juan Islands. In total, 107 unique prey were identified to the species or genus level. Prey in Washington were most commonly Pelagic-Neritic (39.75% FO), Pelagic-Oceanic (38.89%), or Demersal (32.62%).
Samples with identifiable remains collected in Columbia River locations numbered 1821, and prey largely consisted of clupeiform fishes (57.24% FO). Overall, 25 taxonomic families of prey from 16 orders composed the diet. Nine of the 16 orders of prey represented teleost fish, but crustaceans, lamprey, hagfish, and cephalopods were also consumed. Clupeid fishes occurred at 44.97% by FO, followed by 24.95% pleuronectids, 24.57% osmerids, and 22.57% cottids. Salmon were found to occur in a total of 11.4% of scats, with 5.17% of these identified as adults or unspecified, and 6.22% as juveniles. Lamprey species occurred in 17.13% of collected samples.
This literature review examined Pacific Harbor Seal diet across the northern CCLME by stock and geographic boundary, and contained information synthesized from a literature search of peer-reviewed literature, reports, and theses containing dietary information by frequency of occurrence in Harbor Seal scats and stomach. Overall, more than 13,088 scat or stomach samples contained 37 orders, 62 families, and 121 identified genera or species of prey. These prey items primarily consisted of teleost fishes, but also included a number of invertebrates as well as mammals and birds, demonstrating the broad dietary niche of the Pacific Harbor Seal in the areas examined. Coastal stocks of Pacific Harbor Seals largely consumed pleuronectid or clupeiform fishes, while the diet of the inland stocks of seals also consisted largely of perciform, gadiform, salmoniform, and scorpaeniform fishes. Much of the diet of Harbor Seals is largely dependent on what is seasonally abundant or available (Tollit and others 1997a; Middlemas and others 2006); however, this pattern may not always be apparent without consideration of multiple factors (Thomas and others 2011).
Hard-parts-based quantitative dietary analysis, as conducted within a majority of the studies presented, is not without inherent bias (Helm 1984; Cottrell and others 1996; Tollit and others 1997b; Bowen 2000; Browne and others 2002; Laake and others 2002; Arim and Naya 2003; Deagle and Tollit 2007; Phillips and Harvey 2009). However, because of the wide historical availability of this type of data for pinnipeds, it can remain an informative method for describing prey composition and species of interest across regions. Estimation of sample representation of the overall seal population over time is difficult due to logistics of sampling (Helm 1984) and spatio-temporal changes in predator-prey dynamics. According to Trites and Joy (2005), a suggested minimum sample size of 94 Harbor Seal scat samples is required to distinguish moderate effects between areas or time periods in dietary studies. All but 2 studies in this review (Scheffer and Sperry 1931; Roffe and Mate 1984) satisfied this criterion; however, the former represented a unique study site, and the latter represented the earliest available study in this review's regions of interest.
The rate of consumption of salmonids by pinnipeds and other marine mammal predators is of long-term management interest (Adams and others 2016). Most studies contained in this review were designed to estimate the prevalence of Harbor Seal consumption of salmonids. Therefore, there may be an inherent seasonal or regional bias for salmonids or prey associated with salmonids during specific times of year (McCabe and others 1983). Estimating salmonid composition of diet is especially difficult, in part because seals often do not consume the head of large adult salmonids, precluding otolith analysis (Everitt and others 1981). Additionally, without the benefit of genetic methods, it can be difficult or impossible to identify salmonid prey to the species level (Lance and others 2012). Overall, of 23.74% FO of salmon present in scat or stomach samples, 20% were categorized specifically as adults. Juveniles could potentially be under-reported, as the bones of smaller fish may be completely digested or difficult to identify in scat analysis. Of potential significance is the consumption of prey species that are also predators of juvenile salmon, namely lamprey species. In the Columbia River studies, 11.4% of scats contained salmonid remains, while 17.13% of scats contained remains of lamprey, suggesting a more complex ecological interaction than can be determined by single prey-focused consumption studies. Location is another important aspect to consider, as demonstrated by Wright and others (2007). Fifty percent (n = 6) of scats collected at the upriver haul-out site slightly more than 2 km up the Alsea River contained salmonid remains, while only 8% (n = 111) of scats collected at the mouth of the Alsea River (the 'lower' haul-out site) contained salmonid remains. Additional studies with larger sample sizes could further illuminate these findings.
This review was predominated by studies conducted on the Hood Canal, Oregon-Washington Coastal, and Northern Inland Waters stocks, with poorer representation of the Southern Puget Sound stock. More than 75% of representative samples were collected in Washington in the summer-fall season. This highlights the need for further dietary composition studies in Oregon and the Southern Puget Sound. Future randomly-sampled, year-round studies would most likely help to reduce sampling bias in understanding Harbor Seal diet overall.
This comparative review has highlighted the broad spatial and seasonal diversity of Pacific Harbor Seal prey consumption across the northern CCLME over a time span of more than 80 y, including variable regional and seasonal consumption of salmonid species. Most papers used in this review utilized multi-part hard-part analysis of scat samples, and 2 papers reported the stomach contents of seals. Beyond hard-parts analysis, emerging methods have made dietary analysis of pinnipeds more comprehensive, including stable-isotope analysis (Newsome and others 2010), fatty-acid analysis (Bromaghin and others 2013), and genetic methods (Lamont and others 1996; Kvitrud and others 2005). The behavior and diet of marine mammals can be useful indicators of ecosystem function of the coastal marine environment, and collection of strong baseline data sets is essential for better understanding of this dynamic system.
I would like to thank the Oregon State University Hatfield Marine Science Center for support of this project, M Horning of Oregon State University for his mentorship and support through the completion of my Master's degree and continuing support for my PhD program, and my Master's degree committee members D Reese and K Benoit-Bird. I would also like to thank P Gearin (NOAA, Marine Mammal Laboratory) for allowing me to include additional data, as well as my reviewers for their valuable contributions to the improvement of this manuscript.
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Submitted 14 January 2016, accepted 24 August 2016. Corresponding Editor: Robert Hoffman.
APPENDIX. Prey species of Pacific Harbor Seals reported in the reviewed literature. C = Oregon-Washington Coastal; HC = Hood Canal; SP = Southern Puget Sound; NI = Washington Northern Inland Waters. Scientific Name Common Name Allosmerus elongatus Whitebait Smelt Alosa sapidissima American Shad Ammodytes hexapterus Pacific Sand Lance Amphistichus rhodoterus Redtail Surfperch Anarrhichthys ocellatus Wolf-eel Anoplopoma fimbria Sablefish Argentinid spp Herring Smelt Artedius spp Sculpin Atheresthes stomias Arrow-tooth Rounder Berryteuthis magister Magister Armhook Squid Berryteuthis spp Armhook Squid Brachyistius frenatus Kelp Perch Cancer spp Cancer Crab Chilara taylori Spotted Cusk-eel Chitonotus pugetensis Roughback Sculpin Citharichthys sordidus Pacific Sanddab Citharichthys spp Sanddab Citharichthys stigmaeus Speckled Sanddab Clevelatidia ios Arrow Goby Clupea pallasii Pacific Herring Crangon spp Crangon Shrimp Cryptacanthodes giganteus Giant Wrymouth Cymatogaster aggregata Shiner Perch Diaphus theta California Headlightfish Doryteuthis opalescens Opalescent Inshore Squid Embiotoca lateralis Striped Seaperch Engraulis mordax Californian Anchovy Enophrys bison Buffalo Sculpin Enophrys spp Enophrys Sculpin Entosphenus tridentatus Pacific Lamprey Eopsetta jordani Petrale Sole Eptatretus stoutii Pacific Hagfish Gadus macrocephalus Pacific Cod Gasterosteus aculeatus Three-spined Stickleback Genyonemus lineatns White Croaker Glebocarcinus oregonensis Pygmy Rock Crab Glyptocephalus zachirus Rex Sole Gonatus onyx Clawed Armhook Squid Gonatus spp Gonatus Squid Hemigrapsus oregonensis Oregon Shore Crab Hemilepidotus spinosus Brown Irish Lord Hemilepidotus spp Irish Lord Hexagrammos decagrammus Kelp Greenling Hippoglossoides elassodon Flathead Sole Hydrolagus colliei Spotted Ratfish Hyperprosopon ellipticum Silver Surfperch Hypomesus pretiosus Surf Smelt Icelinus tenuis Spotfin Sculpin Icelus spp Scaled Sculpin Isopsetta isolepis Butter Sole Lampetra ayresii River Lamprey Lampetra spp Lamprey Lepidogobius lepidus Bay Goby Lepidopsetta bilineata Rock Sole Leptocottus armatus Pacific Staghorn Sculpin Liinanda aspera Yellowfin Sole Loligo spp Loligo Squid Lumpenus lampretaeformis Snakeblenny Lumpenus sagitta Snake Prickleback Lycodes pacificus Blackbelly Eelpout Lyopsetta exilis Slender Sole Merluccius productus North Pacific Hake Metacarcinus gracilis Graceful Rock Crab Metacarcinus magister Dungeness Crab Microgadus proximus Pacific Tomcod Microstomus pacificus Dover Sole Mylocheilus caurinus Peamouth Chub Myoxocephalus spp Myoxocephalus Sculpin Nautichthys oculofasciatus Sailfin Sculpin Neotrypaea californiensis Bay Ghost Shrimp Octopus rubescens Pacific Red Octopus Octopus spp Octopus Oncorhynchus gorbuscha Pink Salmon Oncorhynchus keta Chum Salmon Oncorhynchus kisutch Coho Salmon Oncorhynchus kisutch (juv) Coho Salmon (juv) Oncorhynchus mykiss Steelhead Salmon Oncorhynchus nerka Sockeye Salmon Oncorhynchus nerka (juv) Sockeye Salmon (juv) Oncorhynchus spp Salmon spp Oncorhynchus spp (juv) Oncorhychus Salmon (juv) Oncorhynchus tshawytscha Chinook Salmon Oncorhynchus tshaivytscha (juv) Chinook Salmon (juv) Ophiodon elongatus Lingcod Pagurus spp Hermit Crab Pandalus danae Dock Shrimp Parophrys vetulus English Sole Peprilus simillimus Pacific Pompano Petrolisthes cinctipes Flat Porcelain Crab Petrolisthes eriomerus Flattop Crab Phanerodon furcatus White Seaperch Pholis orna ta Saddleback Gunnel Pinnixa schmitti Schmitt Pea Crab Platichthys stellatus Starry Hounder Plectobranchus evides Bluebarred Prickleback Pleuronichthys coenosus C-O Sole Porichthys notatus Plainfin Midshipman Poroclinus rothrocki Whitebarred Prickleback Psettichthys melanostictus Pacific Sand Sole Ptychocheilus oregonensis Northern Pikeminnow Radulinus asprellus Slim Sculpin Rhacochilus vacca Pile Perch Rhinogobiops nicholsii Blackeye Goby Ronquilus jordani Northern Ronquil Sardinops sagax Pacific Sardine Scomber japonicus Pacific Mackerel Scorpaenichthys marmoratus Cabezon Scorpaenidae spp Scorpionfish Spirinchus starksi Night Smelt Spirinchus thaleichthys Longfin Smelt Squalus suckleyi Pacific Spiny Dogfish Stenobrachius leucopsarus Northern Lampfish Syngnathus leptorhynchus Bay Pipefish Thaleichthys pacificus Eulachon Theragra chalcogramma Alaska Pollock Trachurus symmetricus Pacific Jack Mackerel Trichodon trichodon Pacific Sandfish Trichotropis spp Cap Snail Upogebia pugettensis Blue Mud Shrimp Yoldia myalis Comb Yoldia Clam Scientific Name Order Allosmerus elongatus Osmeriformes Alosa sapidissima Clupeiformes Ammodytes hexapterus Perciformes Amphistichus rhodoterus Perciformes Anarrhichthys ocellatus Perciformes Anoplopoma fimbria Scorpaeniformes Argentinid spp Argen tiniformes Artedius spp Scorpaeniformes Atheresthes stomias Pleuronectiformes Berryteuthis magister Teuthida Berryteuthis spp Teuthida Brachyistius frenatus Perciformes Cancer spp Decapoda Chilara taylori Ophidiiformes Chitonotus pugetensis Scorpaeniformes Citharichthys sordidus Pleuronectiformes Citharichthys spp Pleuronectiformes Citharichthys stigmaeus Pleuronectiformes Clevelatidia ios Perciformes Clupea pallasii Clupeiformes Crangon spp Decapoda Cryptacanthodes giganteus Perciformes Cymatogaster aggregata Perciformes Diaphus theta Myctophiformes Doryteuthis opalescens Myopsida Embiotoca lateralis Perciformes Engraulis mordax Clupeiformes Enophrys bison Scorpaeniformes Enophrys spp Scorpaeniformes Entosphenus tridentatus Petromyzontiformes Eopsetta jordani Pleuronectiformes Eptatretus stoutii Myxiniformes Gadus macrocephalus Gadiformes Gasterosteus aculeatus Gasterosteiformes Genyonemus lineatns Perciformes Glebocarcinus oregonensis Decapoda Glyptocephalus zachirus Pleuronectiformes Gonatus onyx Teuthida Gonatus spp Teuthida Hemigrapsus oregonensis Decapoda Hemilepidotus spinosus Scorpaeniformes Hemilepidotus spp Scorpaeniformes Hexagrammos decagrammus Scorpaeniformes Hippoglossoides elassodon Pleuronectiformes Hydrolagus colliei Chimaeriformes Hyperprosopon ellipticum Perciformes Hypomesus pretiosus Osmeriformes Icelinus tenuis Scorpaeniformes Icelus spp Scorpaeniformes Isopsetta isolepis Pleuronectiformes Lampetra ayresii Petromyzontiformes Lampetra spp Petromyzontiformes Lepidogobius lepidus Perciformes Lepidopsetta bilineata Pleuronectiformes Leptocottus armatus Scorpaeniformes Liinanda aspera Pleuronectiformes Loligo spp Teuthida Lumpenus lampretaeformis Perciformes Lumpenus sagitta Perciformes Lycodes pacificus Perciformes Lyopsetta exilis Pleuronectiformes Merluccius productus Gadiformes Metacarcinus gracilis Decapoda Metacarcinus magister Decapoda Microgadus proximus Gadiformes Microstomus pacificus Pleuronectiformes Mylocheilus caurinus Cypriniformes Myoxocephalus spp Scorpaeniformes Nautichthys oculofasciatus Scorpaeniformes Neotrypaea californiensis Decapoda Octopus rubescens Octopoda Octopus spp Octopoda Oncorhynchus gorbuscha Salmoniformes Oncorhynchus keta Salmoniformes Oncorhynchus kisutch Salmoniformes Oncorhynchus kisutch (juv) Salmoniformes (juv) Oncorhynchus mykiss Salmoniformes Oncorhynchus nerka Salmoniformes Oncorhynchus nerka (juv) Salmoniformes (juv) Oncorhynchus spp Salmoniformes Oncorhynchus spp (juv) Salmoniformes (juv) Oncorhynchus tshawytscha Salmoniformes Oncorhynchus tshaivytscha (juv) Salmoniformes (juv) Ophiodon elongatus Scorpaeniformes Pagurus spp Decapoda Pandalus danae Decapoda Parophrys vetulus Pleuronectiformes Peprilus simillimus Perciformes Petrolisthes cinctipes Decapoda Petrolisthes eriomerus Decapoda Phanerodon furcatus Perciformes Pholis orna ta Perciformes Pinnixa schmitti Decapoda Platichthys stellatus Pleuronectiformes Plectobranchus evides Perciformes Pleuronichthys coenosus Pleuronectiformes Porichthys notatus Batrachoidiformes Poroclinus rothrocki Perciformes Psettichthys melanostictus Pleuronectiformes Ptychocheilus oregonensis Cypriniformes Radulinus asprellus Scorpaeniformes Rhacochilus vacca Perciformes Rhinogobiops nicholsii Perciformes Ronquilus jordani Perciformes Sardinops sagax Clupeiformes Scomber japonicus Perciformes Scorpaenichthys marmoratus Scorpaeniformes Scorpaenidae spp Scorpaeniformes Spirinchus starksi Osmeriformes Spirinchus thaleichthys Osmeriformes Squalus suckleyi Squaliformes Stenobrachius leucopsarus Myctophiformes Syngnathus leptorhynchus Syngnathiformes Thaleichthys pacificus Osmeriformes Theragra chalcogramma Gadiformes Trachurus symmetricus Perciformes Trichodon trichodon Perciformes Trichotropis spp Class: Gastropoda Upogebia pugettensis Decapoda Yoldia myalis Nuculoida Scientific Name Family Stock Allosmerus elongatus Osmeridae C Alosa sapidissima Clupeidae C,HC,NI Ammodytes hexapterus Ammodytidae C,HC,NI Amphistichus rhodoterus Embiotocidae C Anarrhichthys ocellatus Anarhichadidae HC,NI Anoplopoma fimbria Anoplopomatidae C,NI Argentinid spp Argentinidae HC,NI Artedius spp Cottidae C Atheresthes stomias Pleuronectidae C,NI Berryteuthis magister Gonatidae HC,NI Berryteuthis spp Gonatidae HC Brachyistius frenatus Embiotocidae C Cancer spp Cancridae C Chilara taylori Ophidiidae c Chitonotus pugetensis Cottidae C,HC Citharichthys sordidus Paralichthyidae C,NI Citharichthys spp Paralichthyidae C Citharichthys stigmaeus Paralichthyidae C,SP,NI Clevelatidia ios Gobiidae C Clupea pallasii Clupeidae C,SP,HC,NI Crangon spp Crangonidae C,HC Cryptacanthodes giganteus Cryptacanthodidae HC Cymatogaster aggregata Embiotocidae C,SP,HC,NI Diaphus theta Myctophidae HC,NI Doryteuthis opalescens Loliginidae C,HC,NI Embiotoca lateralis Embiotocidae C Engraulis mordax Engraulidae C,HC,NI Enophrys bison Cottidae C,HC Enophrys spp Cottidae SP,NI Entosphenus tridentatus Petromyzontidae C,HC,NI Eopsetta jordani Pleuronectidae C,NI Eptatretus stoutii Myxinidae C Gadus macrocephalus Gadidae C,HC,NI Gasterosteus aculeatus Gasterosteidae C,HC,NI Genyonemus lineatns Sciaenidae C,NI Glebocarcinus oregonensis Cancridae HC Glyptocephalus zachirus Pleuronectidae C,SP,HC,NI Gonatus onyx Gonatidae HC Gonatus spp Gonatidae HC,NI Hemigrapsus oregonensis Varunidae HC Hemilepidotus spinosus Cottidae C Hemilepidotus spp Cottidae C,HC,NI Hexagrammos decagrammus Hexagrammidae C,NI Hippoglossoides elassodon Pleuronectidae C,NI Hydrolagus colliei Chimaeridae HC Hyperprosopon ellipticum Embiotocidae C Hypomesus pretiosus Osmeridae C,HC,NI Icelinus tenuis Cottidae C Icelus spp Cottidae C,HC Isopsetta isolepis Pleuronectidae C,NI Lampetra ayresii Petromyzontidae C,NI Lampetra spp Petromyzontidae C Lepidogobius lepidus Gobiidae c Lepidopsetta bilineata Pleuronectidae C,NI Leptocottus armatus Cottidae C, SP, HC, NI Liinanda aspera Pleuronectidae C Loligo spp Loliginidae C,HC Lumpenus lampretaeformis Stichaeidae HC Lumpenus sagitta Stichaeidae C,NI Lycodes pacificus Zoarcidae NI Lyopsetta exilis Pleuronectidae C,SP,HC,NI Merluccius productus Merlucciidae C,SP,HC,NI Metacarcinus gracilis Cancridae HC Metacarcinus magister Cancridae HC Microgadus proximus Gadidae C,SP,HC,NI Microstomus pacificus Pleuronectidae C,SP,HC,NI Mylocheilus caurinus Cyprinidae C Myoxocephalus spp Cottidae NI Nautichthys oculofasciatus Hemitripteridae NI Neotrypaea californiensis Callainassidae C,HC Octopus rubescens Octopodidae C,HC,NI Octopus spp Octopodidae C,HC Oncorhynchus gorbuscha Salmonidae NI Oncorhynchus keta Salmonidae HC,NI Oncorhynchus kisutch Salmonidae C,HC Oncorhynchus kisutch (juv) Salmonidae (juv) HC Oncorhynchus mykiss Salmonidae C,NI Oncorhynchus nerka Salmonidae C,HC,NI Oncorhynchus nerka (juv) Salmonidae (juv) HC Oncorhynchus spp Salmonidae C,HC Oncorhynchus spp (juv) Salmonidae (juv) C Oncorhynchus tshawytscha Salmonidae C,HC,NI Oncorhynchus tshaivytscha (juv) Salmonidae (juv) HC, NI Ophiodon elongatus Hexagrammidae C,HC,NI Pagurus spp Paguridae HC Pandalus danae Pandalidae HC Parophrys vetulus Pleuronectidae C,SP,HC,NI Peprilus simillimus Stromateidae C Petrolisthes cinctipes Porcellanidae HC Petrolisthes eriomerus Porcellanidae HC Phanerodon furcatus Embiotocidae C,SP Pholis orna ta Pholidae C Pinnixa schmitti Pinnotheridae HC Platichthys stellatus Pleuronectidae C,HC,NI Plectobranchus evides Stichaeidae C Pleuronichthys coenosus Pleuronectidae NI Porichthys notatus Batrachoididae C,SP,HC,NI Poroclinus rothrocki Stichaeidae C Psettichthys melanostictus Pleuronectidae C,HC,NI Ptychocheilus oregonensis Cyprinidae NI Radulinus asprellus Cottidae C Rhacochilus vacca Embiotocidae C,SP,HC,NI Rhinogobiops nicholsii Gobiidae C Ronquilus jordani Bathymasteridae C,HC Sardinops sagax Clupeidae C,HC,NI Scomber japonicus Scombridae C,HC,NI Scorpaenichthys marmoratus Cottidae C Scorpaenidae spp Scorpaenidae C,NI Spirinchus starksi Osmeridae C Spirinchus thaleichthys Osmeridae c Squalus suckleyi Squalidae C,HC,NI Stenobrachius leucopsarus Myctophidae HC,NI Syngnathus leptorhynchus Syngnathidae NI Thaleichthys pacificus Osmeridae C,HC,NI Theragra chalcogramma Gadidae SP,HC,NI Trachurus symmetricus Carangidae C Trichodon trichodon Trichodontidae C,NI Trichotropis spp Capulidae HC Upogebia pugettensis Upogebiidae HC Yoldia myalis Yoldiidae HC Scientific Name Region Allosmerus elongatus OR,WA,CR Alosa sapidissima OR,WA,CR Ammodytes hexapterus OR,WA,CR Amphistichus rhodoterus WA,CR Anarrhichthys ocellatus WA Anoplopoma fimbria OR,WA,CR Argentinid spp WA Artedius spp OR Atheresthes stomias OR,WA Berryteuthis magister WA Berryteuthis spp WA Brachyistius frenatus WA Cancer spp OR,WA,CR Chilara taylori OR Chitonotus pugetensis OR,WA Citharichthys sordidus OR,WA,CR Citharichthys spp OR,WA Citharichthys stigmaeus OR,WA,CR Clevelatidia ios OR Clupea pallasii OR,WA,CR Crangon spp OR,WA,CR Cryptacanthodes giganteus WA Cymatogaster aggregata OR,WA,CR Diaphus theta WA Doryteuthis opalescens WA Embiotoca lateralis OR Engraulis mordax OR,WA,CR Enophrys bison WA Enophrys spp WA Entosphenus tridentatus OR,WA,CR Eopsetta jordani OR,WA,CR Eptatretus stoutii OR,WA,CR Gadus macrocephalus OR,WA Gasterosteus aculeatus OR,WA Genyonemus lineatns WA Glebocarcinus oregonensis WA Glyptocephalus zachirus OR,WA,CR Gonatus onyx WA Gonatus spp WA Hemigrapsus oregonensis WA Hemilepidotus spinosus WA Hemilepidotus spp OR,WA,CR Hexagrammos decagrammus OR,WA Hippoglossoides elassodon OR,WA Hydrolagus colliei WA Hyperprosopon ellipticum OR Hypomesus pretiosus OR,WA,CR Icelinus tenuis WA Icelus spp CR Isopsetta isolepis OR,WA,CR Lampetra ayresii OR,WA,CR Lampetra spp OR,WA,CR Lepidogobius lepidus OR,WA Lepidopsetta bilineata OR,WA Leptocottus armatus OR,WA,CR Liinanda aspera WA Loligo spp OR,WA,CR Lumpenus lampretaeformis WA Lumpenus sagitta WA,CR Lycodes pacificus WA Lyopsetta exilis OR,WA Merluccius productus OR,WA,CR Metacarcinus gracilis WA Metacarcinus magister WA Microgadus proximus OR,WA,CR Microstomus pacificus OR,WA,CR Mylocheilus caurinus OR,CR Myoxocephalus spp WA Nautichthys oculofasciatus WA Neotrypaea californiensis OR,WA,CR Octopus rubescens OR,WA,CR Octopus spp OR,WA Oncorhynchus gorbuscha WA Oncorhynchus keta WA Oncorhynchus kisutch OR,WA Oncorhynchus kisutch (juv) WA Oncorhynchus mykiss OR,WA,CR Oncorhynchus nerka WA,CR Oncorhynchus nerka (juv) WA Oncorhynchus spp OR,WA Oncorhynchus spp (juv) OR Oncorhynchus tshawytscha OR,WA Oncorhynchus tshaivytscha (juv) WA Ophiodon elongatus OR,WA Pagurus spp WA Pandalus danae WA Parophrys vetulus OR,WA,CR Peprilus simillimus WA Petrolisthes cinctipes WA Petrolisthes eriomerus WA Phanerodon furcatus OR,WA Pholis orna ta OR Pinnixa schmitti WA Platichthys stellatus OR,WA,CR Plectobranchus evides WA Pleuronichthys coenosus WA Porichthys notatus WA Poroclinus rothrocki OR,WA,CR Psettichthys melanostictus OR,WA,CR Ptychocheilus oregonensis WA Radulinus asprellus OR,CR Rhacochilus vacca OR,WA Rhinogobiops nicholsii OR Ronquilus jordani WA Sardinops sagax OR,WA Scomber japonicus OR,WA Scorpaenichthys marmoratus OR Scorpaenidae spp WA Spirinchus starksi OR Spirinchus thaleichthys OR,WA,CR Squalus suckleyi WA Stenobrachius leucopsarus WA Syngnathus leptorhynchus WA Thaleichthys pacificus OR,WA,CR Theragra chalcogramma WA Trachurus symmetricus OR,WA Trichodon trichodon OR,WA,CR Trichotropis spp WA Upogebia pugettensis WA Yoldia myalis WA TABLE 1. Summary of reviewed papers and methods of identifying Pacific Harbor Seal prey, listed alphabetically. Stock: WOC = Washington-Oregon Coastal; SPS = Southern Puget Sound; HC = Hood Canal; NIW = Northern Inland Waters. Study location: CR = Columbia River. Evaluation seasons; W = winter; Spr = spring; S = summer; F = fall; AS = all seasons. Author(s), year Study location Beach and others 1985 Tillamook Bay OR, Grays Harbor WA, Willapa Bay WA, Desdemona Sands CR Brown and Mate 1983 Netarts Bay, OR Browne and others 2002 Desdemona Sands, CR Everitt and others 1981 Protection and Gertrude Islands, WA Gearin and others 1998 Ozette River, WA Graybill 1981 Coos Bay, OR Lance and Jeffries 2009a Puget Sound, Eastern Bays, San Juan Islands, WA Lance and others 2012 San Juan Islands, WA Luxa and Acevedo- Salish Sea Guitierrez 2013 Orr and others 2004 Umpqua River, OR Roffe and Mate 1984 Rogue River, OR Scheffer and Sperry 1931 Puget Sound, WA Thomas and others 2011 Protection Island, WA Wright and others 2007 Alsea River, OR Author(s), year Stock(s) Season Sampling Year(s) Beach and others 1985 WOC AS 1980-1982 Brown and Mate 1983 WOC S, F 1977-1979 Browne and others 2002 WOC Spr, S, F 1995-1997 Everitt and others 1981 SPS, NIW AS 1978-1979 Gearin and others 1998 WOC Spr, S 1998 Graybill 1981 WOC AS 1978-1981 Lance and Jeffries 2009a HC, NIW AS 1997-2006 Lance and others 2012 HC AS 2005-2008 Luxa and Acevedo- NIW Spr, S, F 2006 Guitierrez 2013 Orr and others 2004 WOC Spr, F 1997-1998 Roffe and Mate 1984 NIW AS 1976-1978 Scheffer and Sperry 1931 HC AS 1927-1930 Thomas and others 2011 NIW Spr, S 2009 Wright and others 2007 WOC F 2002 Author(s), year Evaluation method Beach and others 1985 Scat otoliths, teeth, beaks Brown and Mate 1983 Visual survey, scat otoliths and teeth Browne and others 2002 Scat bones, teeth, otoliths, beaks Everitt and others 1981 Scat otoliths Gearin and others 1998 Scat vertebrae, gill rakers, optic capsules, teeth and mouthparts Graybill 1981 Scat otoliths, beaks Lance and Jeffries 2009a Scat bones, otoliths, beaks Lance and others 2012 Scat bones, otoliths, beaks, cartilage Luxa and Acevedo- Scat otoliths, bones, Guitierrez 2013 beaks, cartilage Orr and others 2004 Scat otoliths, beaks, cartilage, bones, statolith Roffe and Mate 1984 Stomach bones, beaks, otoliths Scheffer and Sperry 1931 Stomach content analysis Thomas and others 2011 Scat bone, otolith, beaks Wright and others 2007 Scat otoliths, beaks, gill rakers, vertebrae, visual survey, genetic analysis Author(s), year Samples with remains ([SIGMA] = 10,868) Beach and others 1985 1086 Brown and Mate 1983 95 Browne and others 2002 1385 Everitt and others 1981 230 Gearin and others 1998 330 Graybill 1981 296 Lance and Jeffries 2009a 6796 Lance and others 2012 1683 Luxa and Acevedo- 198 Guitierrez 2013 Orr and others 2004 651 Roffe and Mate 1984 14 stomachs Scheffer and Sperry 1931 81 stomachs Thomas and others 2011 126 Wright and others 2007 117 TABLE 2. Summary of additional reviewed papers examining Pacific Harbor Seal behavior or dietary composition in the Northern CCLME using non-FO methods, listed alphabetically by method. Category Author(s), Year Method (s) Visual survey or non- Bayer 1985 Visual survey, radio FO dietary assessment telemetry, captive assessment of hard parts scatology Calambokidis and FO dietary others 1978 consumption with no total sample size London 2006 Visual survey, molecular scatology London and others Visual observation of 2003 predation, molecular and hard parts scatology Riemer and Brown 1997 Hard parts scatology Tallman and others Visual observation of 2004 predation Zamon 2001 Visual observation of predation Captive dietary Cottrell and others Captive feeding studies and modeled 1996 assessment of hard feeding experiments parts scatology methods Harvey 1989 Captive feeding assessment of hard parts scatology methods Phillips and Harvey Captive feeding 2009 assessment of hard parts scatology methods Trites and Joy 2005 Modeling and controlled feeding experiment Spatial telemetry or Berejikian and others Acoustic telemetry modeling 2016 assessment of seal- salmon interactions Brown and others 2013 Marine mammals as autonomous environmental samplers Grigg and others 2009 Satellite telemetry/ scales of predator/ prey interaction Hardee 2008 Satellite telemetry Peterson and others Satellite telemetry 2012 Wilson and others Fine-scale analysis 2014 of foraging behavior Technical reports and Carretta and others Marine mammal stock summaries 2015 assessments Courbis 2009 Summary of literature; pinniped- fisheries interactions Harvey and Weise 1997 Technical assessment Scordino 2010 Technical summary USDC 1999 Technical report to congress Emerging/alternative Balbag 2016 Molecular scatology methods of dietary assessment Bromaghin and others Quantitative fatty 2013 acid signature analysis Browne and others Multiple skeletal 2002 structure identification Howard and others in scat Bioenergetics 2013 model Laake and others 2002 Comparison of estimation models Lance and Jeffries Microsatellite 2009b analysis of prey in scat NMML 1996 Biomass consumption estimation modeling Purcell and others Molecular scatology 2004 Rhydderch and others Genetic 2004 discrimination of salmonid stocks subject to pinniped predation TABLE 3. Top prey species occurring in: (1) >10% of samples overall; (2) >10% of samples for the Oregon-Washington Coastal stock; and (3) >10% of scats of the Northern Inland Waters stock. PC = prey composition. Common name Scientific name Total FO (%) (1) SAMPLE OVERALL (n = 13,088) North Pacific Hake Merluccius productus 35.20 Pacific Herring Clupea pallasii 32.01 Shiner Perch Cymatogaster aggregate/ 11.06 (2) SAMPLE OR-WA (n = 3960) Pacific Herring Clupea pallasii 23.32 Pacific Staghorn Sculpin Leptocottus armatus 19.70 Pacific Tomcod Microgadus proximus 17.34 North Pacific Hake Merluccius productus 14.20 Californian Anchovy Engraulis mordax 12.55 Eulachon Thaleichthys pacificus 10.44 Shiner Perch Cymatogaster aggregata 10.36 (3) NORTHERN INLAND WATERS (n = 1792) Pacific Herring Clupea pallasii 43.76 Pacific Sand Lance Ammodytes hexapterus 15.75 Shiner Perch Cymatogaster aggregata 13.79 Alaska Pollock Theragra chalcogramma 13.70 Californian Anchovy Engraulis mordax 10.35 Three-spined Stickleback Gasterosteus aculeatus 10.06 Common name Total PC (%) (1) SAMPLE OVERALL North Pacific Hake 16.28 Pacific Herring 14.80 Shiner Perch 5.12 (2) SAMPLE OR-WA Pacific Herring 9.72 Pacific Staghorn Sculpin 8.21 Pacific Tomcod 7.23 North Pacific Hake 5.92 Californian Anchovy 5.23 Eulachon 4.36 Shiner Perch 4.32 (3) NORTHERN INLAND WATERS Pacific Herring 16.83 Pacific Sand Lance 6.05 Shiner Perch 5.30 Alaska Pollock 5.27 Californian Anchovy 3.98 Three-spined Stickleback 3.87 TABLE 4. Top prey by frequency of occurrence >20% for 3 seasonal groups. Summer-fall FO (%) Winter-spring FO (%) (n = 10,026) (n = 2164) Gadiformes 54.26 Clupeiformes 56.62 Clupeiformes 51.30 Gadiformes 48.74 Salmoniformes 24.96 Perciformes 29.67 Perciformes 22.09 Pleuronectiformes 24.00 Scorpaeniformes 22.42 Summer-fall All seasons FO (%) (n = 10,026) (n = 898) Gadiformes Clupeiformes 52.10 Clupeiformes Gadiformes 32.47 Salmoniformes Pleuronectiformes 30.40 Perciformes Perciformes 27.24 Scorpaeniformes 24.80
Department of Fisheries and Wildlife and Marine Mammal Institute, Oregon State University, 2030 SE Marine Science Drive, Newport, OR, USA; email@example.com
Caption: FIGURE 1. Locations represented by studies of Harbor Seal prey consumption by FO in the northern CCLME, by author and approximate location of sample collection. Duplicate markers have been removed for clarity.
Caption: FIGURE 3. Locations represented by studies of Harbor Seal prey consumption by FO in the Puget Sound, by author. Duplicate markers have been removed for clarity.
Caption: FIGURE 2. Total sample size representation by season (winter-spring, summer-fall, or all seasons; n = 13,088). ALL SEASONS 7% WINTER-SPRING 15% SUMMER-FALL 77% Note: Table made from pie chart.
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|Publication:||Northwestern Naturalist: A Journal of Vertebrate Biology|
|Date:||Mar 22, 2017|
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