Analysis of straying variation in Alaskan hatchery chinook salmon (Oncorhynchus tshawytscha) following transplantation

1999 ◽  
Vol 56 (4) ◽  
pp. 578-589 ◽  
Author(s):  
Jeffrey J Hard ◽  
William R Heard

In 1976 chinook salmon (Oncorhynchus tshawytscha) gametes from the Chickamin and Unuk rivers in southeastern Alaska were transplanted 250 km to establish hatchery runs at Little Port Walter (LPW), Baranof Island. From 1977 to 1989, 1 862 058 marked smolts from 12 broods were released from LPW. Homing and straying were estimated from adult recoveries at 25 locations in Alaska and British Columbia between 1981 and 1989. Of 22 198 LPW fish recovered over this period, 21 934 (98.8%) were collected at LPW. Of 264 fish recovered elsewhere, 38.3% were within 7 km of LPW; 64.4% were within 25 km of LPW. No LPW fish were recovered from the ancestral rivers, but nine fish were recovered from rivers supporting wild chinook salmon. Straying declined with distance from the release site but varied between hatcheries and streams. Straying declined with increasing age and run size. Straying was similar between the populations but varied among broods, and analysis of straying in experimental groups provided evidence for a heritable component. Males strayed more often than females. Population, gender, run size, and recovery age interacted to produce substantial variation in straying, indicating that run composition can produce complex straying responses.

1997 ◽  
Vol 54 (7) ◽  
pp. 1585-1592 ◽  
Author(s):  
M J Bradford ◽  
G C Taylor

Immediately after emergence from spawning gravels, fry of stream-type chinook salmon (Oncorhynchus tshawytscha) populations from tributaries of the upper Fraser River, British Columbia, distribute themselves downstream from the spawning areas, throughout the natal stream, and into the Fraser River. We tested the hypothesis that this range in dispersal distances is caused by innate differences in nocturnal migratory tendency among individuals. Using an experimental stream channel, we found repeatable differences in downstream movement behaviour among newly emerged chinook fry. Fish that moved downstream were larger than those that held position in the channel. However, the incidence of downstream movement behaviours decreased over the first 2 weeks after emergence. We propose that the variation among individuals in downstream movement behaviour we observed leads to the dispersal of newly emerged fry throughout all available rearing habitats. Thus, between- and within-population variation in the freshwater life history observed in these populations may be caused by small differences in the behaviour of individuals.


1994 ◽  
Vol 51 (8) ◽  
pp. 1737-1751 ◽  
Author(s):  
Clifford L. K. Robinson ◽  
Daniel M. Ware

A trophodynamics model is used to estimate annual plankton and fish production for the southern British Columbia continental shelf during 1985–89. The model describes the feeding interactions among diatoms, copepods, euphausiids, juvenile and adult Pacific herring (Clupea pallasi), Pacific hake (Merluccius productus), chinook salmon (Oncorhynchus tshawytscha), and spiny dogfish (Squalus acanthias) and is forced by empirical seasonal patterns in upwelling, sea surface temperature, and solar radiation. The most important simulation results are that (1) there is an imbalance between fish consumption and euphausiid production during the summer upwelling season, (2) the biomass and arrival timing of migratory hake significantly influence plankton and fish production, and (3) about 11% of the 332 g C∙m−2∙yr−1 annual diatom production is transferred to copepods and euphausiids and 1.0% of the diatom production to fish, while 27.5% of the 11.9 g C∙m−2∙yr−1 euphausiid production is consumed by herring and hake. The high plankton and fish production on the southern British Columbia shelf is comparable with other productive coastal upwelling regions.


1971 ◽  
Vol 28 (12) ◽  
pp. 1921-1921 ◽  
Author(s):  
Jun Ito ◽  
R. R. Parker

An occurrence of Pacific herring (Clupea harengus pallasi) predation on juvenile chinook salmon (Oncorhynchus tshawytscha) is described. This is the first recorded incidence of this particular predator–prey relation.


1994 ◽  
Vol 51 (S1) ◽  
pp. 267-276 ◽  
Author(s):  
R. E. Withler ◽  
T. D. Beacham ◽  
R. F. Watkins ◽  
T. A. Stevens

The chinook salmon DNA probe B2-2 was used to distinguish farm-reared (from two commercial farms) and native chinook salmon (Oncorhynchus tshawytscha) that were sampled from five populations on the west coast of Vancouver island. The Big Qualicum River population (east coast of Vancouver Island), which is believed to be the main progenitor of domesticated broodstocks used for aquaculture in British Columbia, was also sampled. The presence or absence and integrated optical densities (IODs) of three DNA fragments at 8.3 kilo base pairs (kbp) (band 1), 6.5 kbp (band 2), and 5.6 kbp (band 3) in the hybridization patterns of B2-2 on BamHI-restricted DNA were recorded for 269 chinook salmon. The frequency of occurrence of bands 2 and 3, and all seven measurements made of the relative and absolute values of the IODs of the three bands, varied significantly among populations. The IOD of band 3 provided the best discrimination among populations. The Big Qualicum and two fish farm populations were differentiated from all five west coast native populations. Discriminant analysis and a neural network were used independently to classify correctly to type an average of 97% of the native and 83% of the farm west coast DNA patterns used as test samples.


1986 ◽  
Vol 28 (4) ◽  
pp. 587-594 ◽  
Author(s):  
R. E. Withler

Inheritance of the ability to deposit coloured dietary carotenoid pigments in muscle tissue was examined in 16 seapen-reared families of chinook salmon (Oncorhynchus tshawytscha) from the Quesnel River, British Columbia. The progeny red:white ratio varied significantly among families in two sample periods but not between sample periods for individual families. There was no difference between the sexes in proportions of red and white individuals. Total carotenoid extraction of muscle tissue samples from 152 progeny revealed that white individuals contained less carotenoid per gram of tissue (0.24 ± 0.04 μg) than did red ones (3.37 ± 0.14 μg). Estimates of the heritability of flesh colour, when treated as a threshold trait, were 0.93 (sire component) and 0.71 (dam component). A genetic model that invokes two genetic loci, each with two alleles, was proposed to explain the inheritance of flesh colour in Quesnel River chinook salmon. At each locus, one copy of a "red-determining" allele is required for coloured carotenoid pigments to be deposited in muscle tissue. The anomalous red:white ratios among the progeny of one male parent could not be accounted for by tetrasomy or pseudolinkage in conjunction with the proposed model.Key words: Oncorhynchus, salmon, carotenoids, heritability.


1985 ◽  
Vol 42 (2) ◽  
pp. 287-291 ◽  
Author(s):  
Peter J. Rombough

Eggs of chinook salmon (Oncorhynchus tshawytscha) were segregated into eight size groups (range 163–437 mg) and incubated at 5, 7.5, 10, and 12.5 °C. The time required to reach maximum alevin wet weight (MAWW) varied significantly (p < 0.01) both with mean incubation temperature (T °C) and with initial egg weight (W mg). A good (R2 = 98.4%, n = 21) prediction of days postfertilization to MAWW (D) is given by[Formula: see text]Optimal ponding times are closely associated with the attainment of MAWW and can be estimated using this equation. Data relating mean incubation temperatures (T) to actual ponding time were collected from 17 hatcheries throughout British Columbia. The equation[Formula: see text]where D′ is days postfertilization to ponding, provided the best fit to the data (R2 = 97.5%, n = 85). Hatchery ponding times were not significantly different from times to MAWW predicted for 200-mg eggs.


2018 ◽  
Vol 24 (2) ◽  
pp. 189 ◽  
Author(s):  
Monika W. Shields ◽  
Jimmie Lindell ◽  
Julie Woodruff

The salmon-eating Southern Resident killer whales (Orcinus orca) of the north-eastern Pacific Ocean are listed as endangered both in the United States and Canada. Their critical habitat has been defined as the region of the inland waters of Washington State and British Columbia known as the Salish Sea, where they have traditionally spent much of their time from spring through fall. Using reports from experienced observers to sightings networks, we tracked the daily presence of the Southern Residents in these waters from 1 April to 30 June from 1994 through 2016. We found that the escapement estimates of spring Chinook salmon (Oncorhynchus tshawytscha) on the Fraser River in British Columbia were a significant predictor of the cumulative presence/absence of the whales throughout the spring season. There was also a difference in both whale presence and salmon abundance before and after 2005, suggesting that the crash in Chinook salmon numbers has fallen below threshold where it is worthwhile for the whales to spend as much time in the Salish Sea. The use of the Salish Sea by the Southern Residents has declined in the spring months as they are either foraging for Chinook salmon elsewhere or are shifting to another prey species. In order to continue providing necessary protections to this endangered species, critical habitat designations must be re-evaluated as this population of killer whales shifts its range in response to prey availability.


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