Spawning site selection in interior Fraser River coho salmon Oncorhynchus kisutch: an imperiled population of anadromous salmon from a snow-dominated watershed

The fitness of female Pacific salmon (Oncorhynchus spp.) with respect to breeding behavior can be partitioned into at least four fitness components: survival to reproduction, competition for breeding sites, success of egg incubation, and suitability of the local environment near breeding sites for early rearing of juveniles. We evaluated the relative influences of habitat features linked to these fitness components with respect to selection of breeding sites by coho salmon (Oncorhynchus kisutch). We also evaluated associations between breeding site selection and additions of large wood, as the latter were introduced into the study system as a means of restoring habitat conditions to benefit coho salmon. We used a model selection approach to organize specific habitat features into groupings reflecting fitness components and influences of large wood. Results of this work suggest that female coho salmon likely select breeding sites based on a wide range of habitat features linked to all four hypothesized fitness components. More specifically, model parameter estimates indicated that breeding site selection was most strongly influenced by proximity to pool-tail crests and deeper water (mean and maximum depths). Linkages between large wood and breeding site selection were less clear. Overall, our findings suggest that breeding site selection by coho salmon is influenced by a suite of fitness components in addition to the egg incubation environment, which has been the emphasis of much work in the past.

Download Full-text

Discriminating coho salmon (Oncorhynchus kisutch) populations within the Fraser River, British Columbia, using microsatellite DNA markers

Molecular Ecology ◽

10.1046/j.1365-294x.1998.00324.x ◽

1998 ◽

Vol 7 (2) ◽

pp. 141-155 ◽

Cited By ~ 123

Author(s):

M. P. SMALL ◽

T. D. BEACHAM ◽

R. E. WITHLER ◽

R. J. NELSON

Keyword(s):

British Columbia ◽

Dna Markers ◽

Microsatellite Dna ◽

Coho Salmon ◽

Oncorhynchus Kisutch ◽

Fraser River ◽

Microsatellite Dna Markers

Download Full-text

Variation in Body Morphology Among British Columbia Populations of Coho Salmon, Oncorhynchus kisutch

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f85-249 ◽

1985 ◽

Vol 42 (12) ◽

pp. 2020-2028 ◽

Cited By ~ 90

Author(s):

Eric B. Taylor ◽

J. D. McPhail

Keyword(s):

British Columbia ◽

Coho Salmon ◽

Function Analysis ◽

Oncorhynchus Kisutch ◽

Fraser River ◽

Strait Of Georgia ◽

Coastal Streams ◽

Morphological Differences ◽

Median Fins ◽

Coastal British Columbia

Ten populations of juvenile coho salmon, Oncorhynchus kisutch, from streams tributary to the upper Fraser River, the lower Fraser River, and the Strait of Georgia region were morphologically compared. Juveniles from coastal streams (Fraser River below Hell's Gate and the Strait of Georgia) were more robust (deeper bodies and caudal peduncles, shorter heads, and larger median fins) than interior Juveniles. Discriminant function analysis indicated that juvenile coho could be identified as to river of origin with 71% accuracy. Juvenile coho from coastal streams were less successfully classified as to stream of origin; however, juveniles could be successfully identified as either coastal or interior with 93% accuracy. Juvenile coho from north coastal British Columbia, Alaska, and the upper Columbia system also fitted this coastal and interior grouping. This suggests that a coastwide coastal–interior dichotomy in juvenile body form exists. Three populations (one interior and two coastal) were studied in more detail. In these populations the coastal versus interior morphology was consistent over successive years, and was also displayed in individuals reared from eggs in the laboratory. Adult coho salmon also showed some of the coastal–interior morphological differences exhibited by juveniles. We concluded that the morphological differences between coastal and interior coho salmon are at least partially inherited.

Download Full-text

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.

Download Full-text

Effect of Temperature, Season, and Fish Size on Acute Lethality of Suspended Sediments to Coho Salmon (Oncorhynchus kisutch)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f91-063 ◽

1991 ◽

Vol 48 (3) ◽

pp. 493-497 ◽

Cited By ~ 36

Author(s):

James A. Servizi ◽

Dennis W. Martens

Keyword(s):

Oxygen Transfer ◽

Coho Salmon ◽

Oncorhynchus Kisutch ◽

Suspended Sediments ◽

Effect Of Temperature ◽

Fraser River ◽

Metabolic Rates ◽

Temperature Dependent ◽

Cough Reflex ◽

The Relationship

Tolerance of underyearling coho salmon (Oncorhynchus kisutch) to Fraser River suspended sediments (SS) at 7 °C was independent of season of the year. However, coho of 0.52 g (4.0 cm) possessed only 35% of the tolerance of larger specimens. Tolerance to SS was temperature dependent, with 96-h LC50 at 1 and 18 °C being 47 and 33%, respectively, of the value at 7 °C. Tolerance was further reduced among underyearling coho which were later found to have a viral kidney infection. Cough reflex, oxygen transfer, oxygen saturation levels, metabolic rates, and capacity to do work all probably affect the relationship between SS tolerance and temperature.

Download Full-text

Sublethal Responses of Coho Salmon (Oncorhynchus kisutch) to Suspended Sediments

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f92-154 ◽

1992 ◽

Vol 49 (7) ◽

pp. 1389-1395 ◽

Cited By ~ 51

Author(s):

James A. Servizi ◽

Dennis W. Martens

Keyword(s):

Blood Sugar ◽

Sockeye Salmon ◽

Coho Salmon ◽

River Sediments ◽

Oncorhynchus Kisutch ◽

Suspended Sediments ◽

Fraser River ◽

Cough Frequency ◽

Naturally Occurring ◽

Sugar Levels

Underyearling coho salmon (Oncorhynchus kisutch) were exposed to sublethal concentrations of Fraser River suspended sediments (SS) in the laboratory. Comparisons with other rivers indicated that Fraser River sediments caused the lowest turbidity for a given SS value. Blood sugar levels (y) were elevated and directly proportional to SS exposure (x) according to y = 5.79 + 4.23(x). Published blood sugar data for adult sockeye salmon (O. nerka) exposed to Fraser River SS were in agreement with the linear relationship for underyearling coho. Cough frequency was elevated approximately eightfold over control levels at 0.24 g SS∙L−1. No increase in cough frequency was observed at 0.02 g SS∙L−1. Avoidance was defined by movement to the surface to escape higher SS at depth. Mean avoidance (y) was related to SS by y = 0.077 + 4.457(x) − 1.547(x2) + 0.202(x3). Mean avoidance was less than 5% up to the inflection point at 2.55 g SS∙L−1 but rose to approximately 25% at 7.0 g SS∙L−1. Laboratory results indicated that sublethal responses could be expected at naturally occurring SS levels in the Fraser River.

Download Full-text