On conducting management-relevant mechanistic science for upriver migrating adult Pacific salmon

Pacific salmon undertake iconic homeward migrations where they move from ocean feeding grounds to coastal rivers where they return to natal spawning sites. However, this migration is physiologically challenging as fish have to navigate past predators, nets, hooks, and dams while dealing with variable flows, warm water temperatures, and pathogens. These challenges often interact in synergistic ways that can sometimes lead to migration failure. The conservation physiology toolbox has led to new understanding of how salmon deal with different challenges with a goal of generating management-relevant science. Given the sensitivity of Pacific salmon to warm temperatures, much research has focused on identifying thermal thresholds. In addition, physiology has informed the development of methods for recovering fish that are exhausted from fisheries interactions and for enhancing passage success at fishways. These successes have arisen in part due to the extent to which we partnered with fisheries managers and other stakeholders to ensure that we were conducting relevant research.

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An Electrophysiological Basis for Olfactory Discrimination in Homing Salmon: A Review

Journal of the Fisheries Research Board of Canada ◽

10.1139/f70-059 ◽

1970 ◽

Vol 27 (3) ◽

pp. 565-586 ◽

Cited By ~ 32

Author(s):

Toshiaki J. Hara

Keyword(s):

Pacific Salmon ◽

Electrical Response ◽

High Amplitude ◽

Polluted Water ◽

Sensitive Period ◽

Young Fish ◽

Spawning Site ◽

Short Period ◽

Sign Stimulus ◽

Spawning Sites

Past and current researches relating to olfactory acuity and discrimination in fishes, with special reference to homing salmon, are reviewed.When the nasal sac of spawning Pacific salmon is stimulated with water from the spawning site a high amplitude electroencephalographic response of characteristic pattern is recorded from the olfactory bulb. This electrical response is specific in the sense that it cannot be evoked by water from spawning sites of other groups of breeding salmon. Further, the salmon respond clearly to water taken from places along their migratory routes below the spawning sites. These findings suggest that olfaction is an important factor in guidance during the final phases of homeward migration of salmon. It is also possible that salmon retrace sequentially a trail of stimuli that is the reverse of that imprinted in the young fish on their seaward migration.Although the available data do not delineate the sensitive period, or the duration of the imprinting process, there is accumulating evidence that only a short period is necessary for imprinting, which may occur when the smolts are in their freshwater life.Recent study on the effect of antimetabolites (puromycin, actinomycin D, or cycloheximide) on olfactory bulbar discrimination in homing salmon suggests that long-term olfactory memory in these fish depends upon continued metabolism of RNA and continued protein synthesis. The possibility that the imprinting process in young fish may be affected by polluted water, which has recently become a serious problem in fisheries, is discussed. The need for electrophysiological as well as biochemical studies at a macromolecular level of the imprinting process is emphasized.Finally, the hypothesis is discussed that a home stream odour may act most effectively as a simple "sign stimulus," which, through the release of a positive rheotropic response, induces the fish to move upstream toward home. This is largely based on the recent experimental observations of the orientation mechanism in several species of teleost fishes.

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VARIATION IN PACIFIC SALMON REPRODUCTIVE BEHAVIOUR ASSOCIATED WITH SPECIES, SEX AND LEVELS OF COMPETITION

Behaviour ◽

10.1163/156853999501270 ◽

1999 ◽

Vol 136 (2) ◽

pp. 179-204 ◽

Cited By ~ 32

Author(s):

Thomas Quinn

Keyword(s):

Pacific Salmon ◽

Local Area ◽

Reproductive Behaviour ◽

Male Aggression ◽

Male And Female ◽

Sexual Display ◽

Resource Space ◽

Intensity Of Competition ◽

Satellite Males ◽

Spawning Sites

AbstractMale and female Pacific salmon compete for different resources; females for suitable spawning sites and males for access to ripe females. Aggression should thus be primarily intra-sexual rather than inter-sexual. When different species are sympatric, males should primarily attack conspecifics whereas females should attack all females, regardless of species because they all compete for the same resource-space. The level of aggression should be a function of density, being relatively low at low densities and peaking at either intermediate or high densities. These predictions were supported in most respects by data collected on the behaviour of adult sockeye (Oncorhynchus nerka), chum (O. keta) and pink (O. gorbuscha) salmon in a large, relatively homogeneous spawning channel. Males almost exclusively attacked other males, especially conspecifics. Females were more likely to attack female heterospecifics than males but still tended to attack conspecifics most often, and also directed many attacks at males. Male aggression and digging, apparently a form of intra-sexual display, were related to density of male conspecifics in the local area, and the intensity of competition from satellite males courting the female.

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Conservation physiology in practice: how physiological knowledge has improved our ability to sustainably manage Pacific salmon during up-river migration

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2012.0022 ◽

2012 ◽

Vol 367 (1596) ◽

pp. 1757-1769 ◽

Cited By ~ 70

Author(s):

Steven J. Cooke ◽

Scott G. Hinch ◽

Michael R. Donaldson ◽

Timothy D. Clark ◽

Erika J. Eliason ◽

...

Keyword(s):

Functional Genomics ◽

Sockeye Salmon ◽

Pacific Salmon ◽

Population Level ◽

Mechanistic Explanation ◽

Conservation Physiology ◽

In The Wild ◽

Capture And Release ◽

Novel Applications ◽

River Migration

Despite growing interest in conservation physiology, practical examples of how physiology has helped to understand or to solve conservation problems remain scarce. Over the past decade, an interdisciplinary research team has used a conservation physiology approach to address topical conservation concerns for Pacific salmon. Here, we review how novel applications of tools such as physiological telemetry, functional genomics and laboratory experiments on cardiorespiratory physiology have shed light on the effect of fisheries capture and release, disease and individual condition, and stock-specific consequences of warming river temperatures, respectively, and discuss how these findings have or have not benefited Pacific salmon management. Overall, physiological tools have provided remarkable insights into the effects of fisheries capture and have helped to enhance techniques for facilitating recovery from fisheries capture. Stock-specific cardiorespiratory thresholds for thermal tolerances have been identified for sockeye salmon and can be used by managers to better predict migration success, representing a rare example that links a physiological scope to fitness in the wild population. Functional genomics approaches have identified physiological signatures predictive of individual migration mortality. Although fisheries managers are primarily concerned with population-level processes, understanding the causes of en route mortality provides a mechanistic explanation and can be used to refine management models. We discuss the challenges that we have overcome, as well as those that we continue to face, in making conservation physiology relevant to managers of Pacific salmon.

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Evaluation of isotopic fractionation error on calculations of marine-derived nitrogen in terrestrial ecosystems

Canadian Journal of Forest Research ◽

10.1139/x05-094 ◽

2005 ◽

Vol 35 (7) ◽

pp. 1604-1616 ◽

Cited By ~ 6

Author(s):

Arthur EL Morris ◽

John M Stark ◽

Barrie K Gilbert

Keyword(s):

Isotope Fractionation ◽

Pacific Salmon ◽

Model Simulation ◽

Isotopic Fractionation ◽

Terrestrial Ecosystems ◽

Riparian Ecosystems ◽

Terrestrial Plants ◽

N Losses ◽

Riparian Plant ◽

Spawning Sites

Pacific salmon (Oncorhynchus spp.) transport nitrogen (N) from oceans to inland ecosystems. Salmon δ15N is higher than δ15N expected in terrestrial plants, so linear two-source mixing models have commonly been used to quantify contributions of marine-derived N (MDN) to riparian ecosystems based on riparian plant δ15N. However, isotopic fractionation potentially contributes to error in MDN estimates by changing δ15N of salmon-derived N appearing in soil and plants. We used a simulation model to examine potential effects of fractionation on MDN estimates. We also measured changes in δ15N and δ13C as N and carbon (C) moved from bear feces into soil, and compared MDN estimates using three different estimates for the marine endmember of a linear mixing model. Simulation demonstrated that fractionation during soil N losses could lead to large overestimations of MDN when δ15N of salmon tissue is used as the marine endmember. δ15N of bear feces was significantly enriched (by 1.9) relative to salmon tissue, but did not change during movement of feces-derived N into soil. In contrast, δ13C decreased by 1.9 between salmon and bear feces and declined an additional 4.2 during movement into soil. We propose a new method for estimating the δ15N of the marine endmember that accounts for isotope fractionation occurring as marine N is cycled in soil. This method uses the proportional difference in soil 15N content between reference and spawning sites to calculate the marine endmember δ15N.

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Movements of adult coho salmon (Oncorhynchus kisutch) during colonization of newly accessible habitat

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f07-087 ◽

2007 ◽

Vol 64 (8) ◽

pp. 1143-1154 ◽

Cited By ~ 50

Author(s):

Joseph H Anderson ◽

Thomas P Quinn

Keyword(s):

Coho Salmon ◽

Pacific Salmon ◽

Oncorhynchus Kisutch ◽

Conservation Strategy ◽

Breeding Behavior ◽

Spawning Site ◽

Radio Transmitters ◽

Accessible Habitat ◽

Initial Process ◽

Spawning Sites

Pacific salmon (Oncorhynchus spp.) have repeatedly exploited new habitat following glacial recession and some artificial introductions, yet the initial process of colonization is poorly understood. Landsburg Diversion Dam on the Cedar River, Washington, excluded salmon from 33 km of habitat for over a century until it was modified to allow passage in 2003. Adult coho salmon (Oncorhynchus kisutch) were sampled as they entered the newly accessible habitat in the first 3 years and a subset received radio transmitters to assess spawning site selection and movement. Annual counts of coho colonists increased over time, and in 2 of 3 years, daily dam passage was positively correlated with river discharge. Contrary to our prediction that coho would spawn in tributaries, all identified spawning sites were in the mainstem Cedar River, though 38% of radio-tagged salmon entered a tributary at least temporarily. Females moved little within the new habitat (average = 5.8 km), whereas males moved extensively (average = 34.8 km), especially when females were scarce. The immediate use of the new habitat by colonists and their widespread movements suggest that exploration is an innate component of salmon breeding behavior, and restoring access to lost habitat merits prioritization as a conservation strategy.

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A veterinary perspective on the conservation physiology and rehabilitation of sea turtles

Conservation Physiology ◽

10.1093/oso/9780198843610.003.0014 ◽

2020 ◽

pp. 241-254

Author(s):

Charles Innis ◽

Kara Dodge

Keyword(s):

Climate Change ◽

Habitat Loss ◽

Sea Turtles ◽

Sea Turtle ◽

Severe Weather ◽

Conservation Physiology ◽

Wildlife Rehabilitation ◽

Life Threatening ◽

Physiological Evaluation ◽

Fisheries Interactions

Sea turtle populations are threatened globally due to anthropogenic and natural factors, including fisheries interactions, watercraft strike, hunting, habitat loss, pollution, climate change, and severe weather. Injured and ill sea turtles are often evaluated by wildlife rehabilitation centres, and many sea turtles can be returned to the wild after rehabilitation. Physiological evaluation of injured and ill sea turtles has revealed life-threatening physiological dysfunction such as acidosis, hypoxia, hypercarbia, dehydration, and hyperkalaemia. Recognition and management of such conditions has improved the outcome for these patients. In addition to clinical advancement, veterinary evaluation has improved our understanding of general sea turtle biology, and increased the safety of procedures such as anaesthesia and laparoscopy. These modalities, combined with emerging biotelemetry technologies, will continue to improve our understanding of sea turtle ecology and conservation physiology.

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Homing in Pacific salmon: mechanisms and ecological basis

Journal of Experimental Biology ◽

10.1242/jeb.199.1.83 ◽

1996 ◽

Vol 199 (1) ◽

pp. 83-91 ◽

Cited By ~ 6

Author(s):

A Dittman ◽

T Quinn

Keyword(s):

Pacific Salmon ◽

Juvenile Salmon ◽

Olfactory Recognition ◽

Seaward Migration ◽

Natal Habitat ◽

Ecological Basis ◽

Feeding Grounds

Pacific salmon (Oncorhynchus spp.) are famous for their homing migrations from oceanic feeding grounds to their natal river to spawn. During these migrations, salmon travel through diverse habitats (e.g. oceans, lakes, rivers), each offering distinct orientation clues and, perhaps, requiring distinct sensory capabilities for navigation. Despite these challenges, homing is generally precise and this philopatry has resulted in reproductively isolated spawning populations with specialized adaptations for their natal habitat. This paper reviews the mechanisms underlying all aspects of salmon homing but emphasizes the final, freshwater phase governed by olfactory recognition of homestream water. Prior to their seaward migration, juvenile salmon learn (imprint on) odors associated with their natal site and later, as adults, use these odor memories for homing. Our understanding of this imprinting process is derived primarily from studies using artificial odorants and hatchery-reared salmon. Recent findings suggest, however, that such studies may underestimate the complexity of the imprinting process in nature.

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