Survival of certain naturally acquired freshwater parasites of juvenile sockeye salmon, Oncorhynchus nerka (Walbaum), in hosts held in fresh and sea water, and implications for their use as population tags

1989 ◽  
Vol 67 (7) ◽  
pp. 1757-1766 ◽  
Author(s):  
R. E. Bailey ◽  
L. Margolis ◽  
G. D. Workman
Keyword(s):  
British Columbia ◽  
Fresh Water ◽  
Water Samples ◽  
Sockeye Salmon ◽  
Sea Water ◽  
Salt Water ◽  
Oncorhynchus Nerka ◽  
The Other ◽  
Maximum Life Span ◽  
Natural Tags

Sockeye salmon (Oncorhynchus nerka) smolts were captured from the outlet streams of Cultus Lake, British Columbia, in 1985 and 1986, and from Fraser Lake, British Columbia, in 1986. Samples collected in 1985 were reared in salt water. Samples collected from each lake in 1986 were divided equally into two groups: one group was reared in fresh water, the other was maintained in salt water. Initially biweekly, and later monthly, subsamples from each group were examined for seven parasite taxa: Myxidium salvelini, Diplostomulum sp. metacercaria, Phyllodistomum umblae, Eubothrium sp. (immature), Proteocephalus sp. (immature), Neoechinorhynchus salmonis, and Salmincola californiensis. The maximum life-span was greater than the duration of the experiments (32–40 weeks) for all species in hosts reared in fresh water (except for S. californiensis, which was removed from all freshwater hosts). Survival of M. salvelini, P. umblae, and S. californiensis was reduced in hosts reared in sea water. No differences in survival of each of Diplostomulum sp. metacercaria, Eubothrium sp., Proteocephalus sp., and N. salmonis were observed between hosts held in fresh water or salt water. Implications for the use of these parasites as natural tags are discussed.

The ontogeny of ultraviolet sensitivity, cone disappearance and regeneration in the sockeye salmon Oncorhynchus nerka

2000 ◽  
Vol 203 (7) ◽  
pp. 1161-1172 ◽  
Author(s):  
I. Novales Flamarique
Keyword(s):  
Sockeye Salmon ◽  
Adult Stage ◽  
Salt Water ◽  
Oncorhynchus Nerka ◽  
The Other ◽  
Small Fish ◽  
Adult Fish ◽  
Long Wavelength ◽  
Electrophysiological Recordings ◽  
Ultraviolet Sensitivity

This study examines the spectral sensitivity and cone topography of the sockeye salmon Oncorhynchus nerka throughout its life history with special emphasis on ultraviolet sensitivity. Electrophysiological recordings from the optic nerve show that ultraviolet sensitivity is greatly diminished at the smolt stage but reappears in adult fish weighing about 201 g. Concomitantly, light microscopy observations of the retina show that ultraviolet cones disappear from the dorsal and temporal retina at the smolt stage but reappear at the adult stage. These changes occur for sockeye salmon raised in fresh water or salt water after smoltification. In contrast to this ultraviolet cycle, the other cone mechanisms (short-, middle- and long-wavelength-sensitive) and the rod mechanism remain present throughout ontogeny. The natural appearance and disappearance of ultraviolet cones in salmonid retinas follows surges in blood thyroxine at critical developmental periods. Their presence coincides with times of prominent feeding on zooplankton and/or small fish that may be more visible under ultraviolet light. It is proposed that the primary function of ultraviolet cones in salmonids is to improve prey contrast.

Eubothrium salvelini (Cestoda: Pseudophyllidea) Impairs Seawater Adaptation of Migrant Sockeye Salmon Yearlings (Oncorhynchus nerka) from Babine Lake, British Columbia

1983 ◽  
Vol 40 (6) ◽  
pp. 821-824 ◽  
Author(s):  
N. P. Boyce ◽  
W. Craig Clarke
Keyword(s):  
British Columbia ◽  
Sockeye Salmon ◽  
Salt Water ◽  
Oncorhynchus Nerka ◽  
Challenge Test ◽  
Infected Fish ◽  
Plasma Sodium ◽  
Elevated Plasma ◽  
Seawater Adaptation ◽  
Test Fish

Migrant sockeye salmon yearlings (Oncorhynchus nerka) were captured at the outlet of Babine Lake, British Columbia, in 1979 and 1980 and transported to the laboratory for evaluation of their seawater adaptability in a 24-h challenge test. Fish infected with the cestode Eubothrium salvelini had a reduced ability to adapt to salt water, as evidenced by greater mortality and elevated plasma sodium levels after challenge. The prevalence of infection was 60% in 1979 and 30% in 1980. In 1979, mortality during challenge was significantly higher among infected than among noninfected fish; the elevation of plasma sodium levels in the infected fish was not statistically significant. In 1980, both infected and noninfected fish had improved seawater adaptability compared with the previous year; infected fish did not suffer significantly higher mortality after challenge but their plasma sodium levels were elevated significantly compared with the noninfected fish. The reduced seawater adaptability of infected fish is likely to reduce their ocean survival considerably.

Resumption of Feeding by and Survival of Adult Sockeye Salmon (Oncorhynchus nerka) Following Advanced Gonad Development

1963 ◽  
Vol 20 (1) ◽  
pp. 95-100 ◽  
Author(s):  
J. R. McBride ◽  
U. H. M. Fagerlund ◽  
M. Smith ◽  
N. Tomlinson
Keyword(s):  
Fresh Water ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Gonad Development ◽  
The Other ◽  
Green Color ◽  
Force Feeding ◽  
In Captivity ◽  
First Time

Adult, migrating, fasting sockeye salmon (Oncorhynchus nerka) were held in captivity in fresh water without spawning well beyond the time when they would normally have done so and died. A few of the fish were then gonadectomized and force feeding was begun. A few unoperated fish were fed similarly while the remainder served as unoperated, unfed controls. The gonads of the operated fish were well developed. After a period of feeding of about four months some fish in each group had survived. The fed fish had regained their green color and much of their weight and vigor, while the surviving unfed fish were extremely emaciated and listless. At this time voluntary feeding by the force-fed fish was observed for the first time, and it was then found that the five surviving unfed controls would also take food voluntarily. While two of these fish died without apparent improvement in their condition, the other three gradually regained green color, weight and vigor.

Estimating Stock Composition of Migrating Juvenile Fraser River (British Columbia) Sockeye Salmon, Oncorhynchus nerka, Using Parasites as Natural Tags

1988 ◽  
Vol 45 (4) ◽  
pp. 586-591 ◽  
Author(s):  
R. E. Bailey ◽  
L. Margolis ◽  
C. Groot
Keyword(s):  
British Columbia ◽  
Maximum Likelihood ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Fraser River ◽  
Dominant Group ◽  
Strait Of Georgia ◽  
Natural Tags ◽  
Lake Washington ◽  
The Individual

Simulated mixtures of juvenile sockeye salmon (Oncorhynchus nerka) were constructed using parasite data to represent proportionally the major component stocks of Fraser River and Lake Washington sockeye migrating within the Strait of Georgia, British Columbia, in 1982–84. Samples of migrating juveniles were also collected from Bedwell Harbour, South Pender Island, British Columbia, each year and analyzed for parasites and stock composition. The compositions of simulated and sample mixtures were estimated using a maximum likelihood stock composition model. Simulated mixture compositions were accurately estimated for most stocks for all year-classes. When significant misassignment occurred between stocks, the stocks were analyzed as a complex using the allocate-sum procedure. Sample mixture estimates correctly identified the dominant stock for each year-class, although for 1984 the dominant group was determined as a complex of three stocks because the individual stocks were not distinguishable. The results indicate that it is feasible to use parasites as natural tags to estimate stock compositions of migrating juvenile sockeye salmon in the Strait of Georgia.

Institutional Learning and Spawning Channels for Sockeye Salmon (Oncorhynchus nerka)

1992 ◽  
Vol 49 (6) ◽  
pp. 1126-1136 ◽  
Author(s):  
Ray Hilborn
Keyword(s):  
British Columbia ◽  
Fisheries Management ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Decision Makers ◽  
The Other ◽  
Institutional Learning ◽  
1960S And 1970S ◽  
The 1960S ◽  
Design Construction

In the 1960s and 1970s, six artificial spawning channels for sockeye salmon (Oncorhynchus nerka) were constructed in British Columbia. I use the evaluation of these facilities and the response to the evaluation to test the hypothesis that fisheries management agencies can learn from experience. One of the facilities was almost immediately determined to be successful, but it took approximately 20 yr for the agency to evaluate the success of the other five. The evaluation was ambiguous for three of these. Only when facilities were overwhelmingly successful or total failures did clear answers emerge. The Canadian Department of Fisheries and Oceans (DFO) has experimented, evaluated, and learned about design, construction, and operation of spawning channels. DFO appears to be less successful at using the evaluation of adult production resulting from spawning channels. Learning appears to work best when goals are well defined, experiments can be conducted and evaluated rapidly, and there is a close organizational connection between decision makers, evaluators, and operators.

Alterations in the Blood Level of Lactic Acid in Certain Salmonoid Fishes Following Muscular Activity.: III. Sockeye Salmon, Oncorhynchus nerka

1957 ◽  
Vol 14 (6) ◽  
pp. 807-814 ◽  
Author(s):  
Edgar C. Black
Keyword(s):  
Lactic Acid ◽  
Fresh Water ◽  
Blood Level ◽  
Sockeye Salmon ◽  
Sea Water ◽  
Oncorhynchus Nerka ◽  
Muscular Activity ◽  
Salmo Gairdneri

The blood level of lactic acid in hatchery-raised sockeye salmon, Oncorhynchus nerka, was studied following 15 minutes of vigorous muscular activity. Yearling salmon acclimated and exercised in fresh water showed a sevenfold increase in blood lactic acid following activity, increasing still further during the first two hours of recovery, as in the Kamloops trout, Salmo gairdneri. Yearling salmon acclimated in sea water for two days and then exercised exhibited higher immediate increase in lactic acid and showed less fatigue. The sea water appeared to aid the yearling salmon in coping with fatigue products. However, two-year-old salmon that had been acclimated a year and a half in sea water showed the same change in lactic acid following exercise as the yearlings in fresh water. Five of 19 two-year-old salmon died following the exercise.

Biochemical Studies on Sockeye Salmon During Spawning Migration: XI. The Free Histidine Content of the Tissues

1960 ◽  
Vol 17 (3) ◽  
pp. 347-351 ◽  
Author(s):  
J. D. Wood ◽  
D. W. Duncan ◽  
M. Jackson
Keyword(s):  
Amino Acid ◽  
Sockeye Salmon ◽  
Alimentary Tract ◽  
Oncorhynchus Nerka ◽  
The Other ◽  
Spawning Migration ◽  
Fraser River ◽  
Initial Value ◽  
Spawning Grounds ◽  
Biochemical Studies

During the first 250 miles (400 km) of spawning migration of Fraser River sockeye salmon (Oncorhynchus nerka) the free histidine content of the muscle, alimentary tract, and head+skin+bones+tail decreased to a small fraction of the initial value. A further decrease occurred in the levels of this amino acid in the alimentary tract during the subsequent 415-mile (657-km) migration to the spawning grounds, no change being observed with the other tissues. Comparatively small changes in free histidine were found with heart, spleen, liver, kidney and gonads during migration.

Fecundity and Egg Retention of Some Sockeye Salmon (Oncorhynchus nerka) Stocks in British Columbia

1986 ◽  
Vol 43 (8) ◽  
pp. 1643-1655 ◽  
Author(s):  
J. I. Manzer ◽  
I. Miki
Keyword(s):  
British Columbia ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Absolute Fecundity ◽  
Egg Retention ◽  
Inadequate Sample Size ◽  
Egg Number ◽  
The Mean ◽  
The Relationship ◽  
Individual Fecundity

The fecundity and egg retention of anadromous female sockeye salmon (Oncorhynchus nerka) collected during 1971–82 from several stocks in British Columbia undergoing controlled fertilization to enhance adult sockeye production were examined. The relationship between egg number and postorbital–hypural length based on 863 females representing 14 stocks was not consistent between all age-types, stocks, and years, probably because of inadequate sample size in some instances. Combined samples, however, revealed a significant positive relationship between postorbital–hypural length and egg number for age 1.2, 1.3, and 2.2 females. Mean absolute fecundity for the respective age-types was 3218, 4125, and 3544 eggs. For samples of 10 or more females, significant stock and annual differences were detected when individual mean absolute fecundity was adjusted to a postorbital–hypural length of 447 mm, but not for females of different age. A comparison of mean fecundities for coastal stocks with historical data for interior British Columbia stocks suggests that coastal stocks are 18% more fecund than interior stocks. Possible causal mechanisms for this regional difference are hypothesized. Examination of 796 carcasses (representing five stocks) for egg retention revealed a range from totally spawned to totally unspawned females, with 56% of the carcasses containing 20 eggs or less and 68% containing 50 eggs or less. The mean egg retention based on all samples combined was estimated to be 6.5% of the mean individual fecundity. This value was reduced to 3.9% when stock means were averaged.

Physiological and Growth Differences in Three Stocks of Underyearling Sockeye Salmon (Oncorhynchus nerka) on Early Entry into Seawater

1994 ◽  
Vol 51 (4) ◽  
pp. 974-980 ◽  
Author(s):  
Stanley D. Rice ◽  
Robert E. Thomas ◽  
Adam Moles
Keyword(s):  
Life History ◽  
Sockeye Salmon ◽  
Salt Water ◽  
Oncorhynchus Nerka ◽  
Early Life History ◽  
Life History Strategies ◽  
Growth Differences ◽  
The Impact ◽  
Lake Type ◽  
River Type

We compared the impact of exposure to seawater on three sockeye salmon (Oncorhynchus nerka) stocks: one that normally migrates to sea as underyearlings (sea-type) and two with the more common life history strategies of 1 (river-type) or 2 (lake-type) yr of freshwater residence prior to seaward migration. Innate differences in survival, ability to regulate tissue chlorides, and oxygen consumption when first introduced into salt water were more evident in April and May when fish were less than 50 mm in length. In fish longer than 50 mm, the only significant differences among the stocks were in saltwater growth. Between June and August, sea-type fish showed faster growth than river-type fish which in turn grew faster than lake-type fish. When introduced into salt water in October, virtually no growth occurred in any stock, regardless of fish size. River-type and lake-type sockeye, which normally overwinter 1 and 2 yr, respectively, in freshwater, can be reared in seawater if underyearlings are raised to a length of 50 mm before release into salt water, similar to the normal life history of sea-type underyearlings. Early life history appears to be influenced more by habitat than by genetics.

scholarly journals Importance of sample size for estimating prevalence: A case example of infectious hematopoietic necrosis viral RNA detection in mixed-stock Fraser River Sockeye salmon (Oncorhynchus nerka), British Columbia, Canada.

2020 ◽  
Author(s):  
Emilie Laurin ◽  
Julia Bradshaw ◽  
Laura Hawley ◽  
Ian A. Gardner ◽  
Kyle A Garver ◽  
...  
Keyword(s):  
British Columbia ◽  
Sample Size ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Small Sample ◽  
Viral Rna ◽  
Sample Sizes ◽  
Apparent Prevalence ◽  
Infectious Hematopoietic Necrosis ◽  
Mixed Stock

Proper sample size must be considered when designing infectious-agent prevalence studies for mixed-stock fisheries, because bias and uncertainty complicate interpretation of apparent (test)-prevalence estimates. Sample size varies between stocks, often smaller than expected during wild-salmonid surveys. Our case example of 2010-2016 survey data of Sockeye salmon (Oncorhynchus nerka) from different stocks of origin in British Columbia, Canada, illustrated the effect of sample size on apparent-prevalence interpretation. Molecular testing (viral RNA RT-qPCR) for infectious hematopoietic necrosis virus (IHNv) revealed large differences in apparent-prevalence across wild salmon stocks (much higher from Chilko Lake) and sampling location (freshwater or marine), indicating differences in both stock and host life-stage effects. Ten of the 13 marine non-Chilko stock-years with IHNv-positive results had small sample sizes (< 30 samples per stock-year) which, with imperfect diagnostic tests (particularly lower diagnostic sensitivity), could lead to inaccurate apparent-prevalence estimation. When calculating sample size for expected apparent prevalence using different approaches, smaller sample sizes often led to decreased confidence in apparent-prevalence results and decreased power to detect a true difference from a reference value.

Sign in / Sign up

Export Citation Format

Share Document