The behavior and ecology of Pacific salmon and trout

“Although movement at different spatial scales has been intensively studied in salmonid fishes (Elliott 1994; Hendry and Stearns 2004; Quinn 2005), the detailed dynamics of dispersal at small spatial scales are not well understood.”

“Populations are defined by their natal streams as well as the seasonal “run” timing of adult freshwater entry and migration to spawning grounds (Quinn, 2018).”

“Because younger Pacific salmon often spawn later in the season than do older salmon (Quinn, 2018), we analyzed these ages separately.”

“…has been long deprived of its annual influx of nutrients from spawning salmon will likely be much less rich in invertebrates and other food needed to support large numbers of juvenile salmon than it was historically, based on studies of streams with and without spawning salmon (see Quinn 2005).”

“Because the amount and energy content of consumed prey affect juvenile salmon growth (Beauchamp 2009; Quinn 2005; Willette et al. 2001), high rates of prey (and energy) acquisition in the estuarine environment can be critical for survival (Levings 1994).”

“Migration in the dense medium of water is energetically costly, especially when migration occurs in streams and rivers, as is the case for many salmonids and cyprinids (Quinn 2005; Brodersen et al. 2008a; Skov et al. 2008; Hulth en et al. 2014a).”

“However, we have also identified the ongoing role of sperm competition and the need to minimize variance in reproductive success by true one-to-one matings or factorial design, although such breeding systems fail to capture the natural processes of selection and competition (Quinn 2005b).”

“Due to their relatively small population sizes and lower commercial value, steelhead populations are not as wellstudied as more common Pacific salmon species (Quinn 2005).”

“In the North Atlantic, the use of the magnetic field together with a genetic component may explain their ability to return from high seas to the vicinity of their natal river, followed by the olfactory identification of their natal river (e.g. see Hasler 1966; Nordeng 1977; Saglio 1983; Quinn 2005).”

“Coastal streams often support populations of both summer-run and winter-run steelhead, whereas interior populations east of the Cascades Mountain range are exclusively summer-run (Myers, Aydin, Walker, Fowler, & Dahlberg, 1996).”

“…relatively few natural origin SRFC smolts (as opposed to hatchery) enter the Gulf of the Faral-lones generally between March and July, with the bulk arriving to sea during April through May (Lindley et al. 2009); presumably this timing matches the peak of prey availability in spring (Quinn 2005).”

“Salmon spend 50–90 % of their lives in the ocean (Quinn 2005).”

“Female salmon bury their eggs in the gravel of streams, rivers, and beaches by digging nests (redds) that protect their embryos from predators and scour (Quinn 2005).”

“Though the PST is an important developmental period for imprinting, freshwater migratory patterns of wild juvenile salmon suggest that the process and timing of imprinting may be much more complex (Quinn 2005).”

“We aimed the DIDSON so as to “bury” the beam into the substrate, thus ensonifying the stream bottom, as we assumed steelhead were migrating close to the bottom to reduce drag and take advantage of reduced current velocities (Quinn 2005).”

“…versus intraspecific competition Competition between species (interspecific) in native assemblages of anadromous salmonids is minimized because the species occupy somewhat different ecological niches (habitats within a common river system) either spatially or temporally (Hearn 1987; Quinn 2005).”

“Studies on patterns of age and size at maturity in salmonids have a long history (Ricker, 1972; Gardner, 1976), with many examples of population-specific variation (reviewed in Groot and Margolis, 1991; Quinn, 2005; Garcia de Leaniz et al., 2007).”

“Additionally, pathogens can cause significant mortality events, while juveniles are rearing in their natal habitat (Quinn 2005).”

“keta) spawn and rear in the lowest reaches of watersheds and migrate a few weeks after they emerge from the gravel (April–May) [36], and may therefore be less vulnerable to scouring where floodplains are intact.”

“Although swimming depth of Pacific salmon in estuarine habitats is not known, in marine waters they exhibit species-specific variation, with steelhead closest to the surface and Chinook the deepest (Quinn 2005).”

“Between 1 and 3% of returning adult salmonids stray from their natal streams to spawn (Stabell, 1984; Quinn, 2005) with an 11% rate of straying in fish of hatchery origin (Quinn, 2005).”

“Marine life is now known to be an important period in the life history of Pacific salmon (Pearcy 1992; Beamish and Mahnken 2001; Quinn 2005).”

“Because spring Chinook generally spawn at higher elevations than fall Chinook (Quinn 2005; Myers et al. 2006), the lower extent coincided with the intersection of each river with the 100-m elevation contour.”

“In general, it is thought that temperature is not an important driver of survival in natural salmon populations based on the observation that salmon embryos are rarely exposed to temperatures that exceed the laboratory-derived ‘lethal’ values across their distribution [11].”

“…this phase are uncertain, and indeed may change from year to year, but likely have to do with distributions and abundances of prey and predators, as well as the size and condition of smolts when entering the sea and the timing of seawater entry (Pearcy, 1992; Koenings et al., 1993; Quinn, 2005).”

“…fishes (genera Oncorhynchus and Salmo ) are renowned for returning to their natal spawning habitats with high accuracy and precision after years at sea [17,29,30], some individuals disperse (termed ‘straying’ and used synony-mously with dispersal hereafter) to non-natal sites to spawn [31,32].”

“…natal freshwater habitat, and a migratory “anadromous” life history where, after a period of juvenile growth and development in freshwater, individuals migrate out to sea to take advantage of productive marine environments before returning to their natal freshwater habitat to spawn (Quinn 2005).”

“Since the publication of these studies, the mechanisms of olfactory imprinting and homing abilities in salmon have been intensively researched in behavioral, electrophysiological, biochemical, and neurobiological studies seeking to clarify the nature of natal river odors (Døving, 1989; Stabell, 1992; Dittman and Quinn…”

“…scenario is possible, given the observed general pattern that Diversity and Distributions, 17, 566–579, ª 2011 Blackwell Publishing Ltd 575 some watersheds serve as ‘magnets’ to straying salmonid species, though why some rivers are more attractive than others is not known (reviewed in Quinn, 2005).”

“Given the intensive migrations these fish must endure to reach optimal feeding grounds in the ocean, and their need to evade predators along the way (Quinn, 2005), if exposure to low DO results in reduced swimming performance, as demonstrated by Bjornn and Reiser (1991), it could have dire indirect consequences on sur…”

“Many researchers have supported this hypothesis [4–7], and artificial chemicals (e.”

“Given the physiological and environmental challenges of migration, it is natural for some death to occur before spawning (Gauthreaux 1980; *Corresponding author: sbenda14@gmail.com Received February 19, 2015; accepted July 13, 2015 1159 D ow nl oa de d by [ O re go n St at e U ni ve Quinn 2005).”

“…or “ocean-maturing” steelhead, Oncorhynchus mykiss (Walbaum, 1792), that optimizes feeding and growth opportunities in the open ocean for a few years before entering fresh water during the late winter or early spring and spawning relatively low in the river system shortly afterwards (Quinn 2005).”

“Behavioral diversity and resilience Salmon have evolved a wide range of behaviors and life history strategies that enable them to persist in spite of considerable variation in environmental conditions (Quinn 2005).”

“The bull trout had δ(15)N values between those of coho and Chinook salmon, two species that tend to be most piscivorous (Quinn 2005), indicating that they fed at a high trophic level.”

“tion of natural stocks with captively bred juveniles [1-4].”

“Redband trout can be found in diverse habitats that include small montane headwater streams, large rivers, desert streams, reservoirs and lakes, and marine waters (Behnke 1992; Muhlfeld 2002; Quinn 2005; Walters et al. 2005).”

“Pink salmon have a strict 2-year life cycle, and in the Puget Sound region, are only available as prey during the odd years (Quinn 2005).”

“Trout also fulfill key 16 ecological roles such as being major predators in their native and introduced range 17 (Quinn, 2011) and linking terrestrial and aquatic food webs and nutrient flows 18 through interactions with riparian zone species (Baxter et al., 2004; Epanchin, Knapp 19 & Lawler, 2010;…”

“Individual 361 mating success therefore decreases because of increased competition among males (Quinn 2011).”

“Data were collected from April 2007 through August of 2008.”

“…other tributaries to the North Pacific, are a species of concern across much of their range (http://www.nmfs.noaa.gov/ pr/species/fish/cohosalmon.htm), and their extended freshwater rearing period (;12–18 months) is representative of Pacific salmon species with a similar life history (Quinn 2005).”

“Over the broad range of latitudes, elevations, and other features that characterize their habitats, growth rates of juveniles and the date and size of seaward migration differ greatly, with a mix of environmental and genetic regulation (Quinn, 2005).”

“…which are valuable in natural populations (Birkeland and Dayton 2005; Law 2007; Hsieh et al. 2010) because of the higher reproductive potential (e.g., greater fecundity and larger eggs) of these fish (Beacham and Murray 1993; Quinn 2005) and their ability to dig deeper redds (Steen and Quinn 1999).”

“Pink salmon are aggressive on spawning grounds (Figure 6-3; Quinn, 2018).”

“For example, Chinook, sockeye, and chum salmon, have variation in age at maturity such that returns from a single brood year are dispersed across several years [75].”

“In general, salmon populations are highly productive at low densities because they are released from competition for breeding sites and, in the case of coho and to a lesser extent ocean-type Chinook salmon, competition for rearing space in streams (Quinn 2005).”

“In streams dominated by cold-water fish assemblages, elevated water temperatures are known to limit the longitudinal distribution of fish, force changes in migration patterns, influence growth rates and even cause mortality (Quinn, 2005).”

“…[1939; cited Correspondence: Anthony J. Gharrett, Fax: 907 796 5445; E-mail: a.gharrett@alaska.edu © 2013 John Wiley & Sons Ltd in Ricker (1972) and Quinn (2005)] recognized that Pacific salmon (Oncorhynchus spp.) conservation requires an understanding of local population structure and cited…”

“Open ocean environments typically have lower food availability, and food sources are more patchily distributed compared to neritic environments ( 40 ).”

“The timing and locations of adult in-migration, spawning aggregations, and smolt out-migration of anadromous fish, and the spatiotemporal availability of other fish, varies extensively among species and among populations in different locations but are generally predictable year to year [16, 17].”

“Individuals that migrate to the marine environment face increased risks associated with predation and other factors, but benefit from increased feeding opportunities, growth and fecundity, especially for females (reviewed by Quinn 2005).”

“In fact, if there is a genetic basis for home angle, this might be one explanatory factor for the generally poor record of transplanting anadromous versus nonanadromous salmonids (Quinn, 2005).”

“…use estuaries for growth (Healey, 1982; Thorpe, 1994), as a physiological transition zone to prepare for migration from freshwater to the sea (Quinn, 2018; Taylor, 1922) and are hypothesized to use estuaries as a refuge from predation (Munsch, Cordell, & Toft, 2016; Quinn, 2018; Thorpe, 1994).”

“Pink salmon, Oncorhynchus gorbuscha (Walbaum 1792), differ from other Pacific salmonids in that they typically spawn in freshwater near the ocean, juveniles migrate to the sea shortly after emerging from gravel nests, they spend a relatively brief period in the ocean (12–16 months) prior to returning to their natal si…”

“The presence of ponds may influence the life history of Chinook, resulting in some Chinook rearing in fresh water for longer than the typical 0–1 summers (Quinn, 2005).”

“Adaptation occurs through selection of successful traits within a locally reproducing population, isolated from other populations by geography or homing behavior (Ricker 1972; Taylor 1991; Quinn 2005; Fraser et al. 2011).”

“This also corresponds to a period of relatively high growth for juvenile salmonids in boreal regions (Huusko et al. 2007), which is likely influenced by stream water chemistry (Quinn 2005).”

“Habitat selection by salmonid species, segregated populations (stocks) and life stages vary widely because the salmonid genotype is very plastic, allowing populations of all species to adapt to a wide range of environmental variation (Quinn, 2005).”