Use of Biochemical Genetic Variants for Identification of Sockeye Salmon (Oncorhynchus nerka) Stocks in Cook Inlet, Alaska

1980 ◽  
Vol 37 (8) ◽  
pp. 1236-1247 ◽  
Author(s):  
W. S. Grant ◽  
G. B. Milner ◽  
P. Krasnowski ◽  
F. M. Utter

We used the geographic distributions of biochemical genetic variants in sockeye salmon (Oncorhynchus nerka) to describe features of its population structure and to identify stocks in commercial catches from the central fishing district of Cook Inlet, Alaska. Allelic frequencies for 6 polymorphic loci were determined for samples of 13 spawning areas using starch gel electrophoresis and were used as the basis of stock classification. The level of genetic variation, estimated by average heterozygosity, was 4.6%. Likelihood ratio tests for heterogeneity among allelic frequencies indicated a significant degree of heterogeneity among spawning areas within the Susitna and Kenai rivers, but not among the spawning areas within the Kasilof River. These tests also indicated that for the Kasilof River, where multi-year samples were taken, allelic frequencies were not significantly different for two consecutive years. Cluster analysis of genetic similarities between samples indicated that the samples from the Kasilof River were distinct from samples of the Kenai and Susitna rivers, but that Kenai and Susitna River samples were not distinct from one another. Maximum likelihood estimates of the stock composition of samples collected from the set- and drift-gillnet fisheries were made on a weekly basis during the commercial fishing season. These estimates indicated that Susitna River fish predominated in the 1976 run into Cook Inlet.Key words: sockeye salmon, Oncorhynchus nerka; stock identification, biochemical genetic variation, population genetics, Cook Inlet, electrophoresis

2006 ◽  
Vol 63 (7) ◽  
pp. 1469-1480 ◽  
Author(s):  
Steven J Cooke ◽  
Scott G Hinch ◽  
Glenn T Crossin ◽  
David A Patterson ◽  
Karl K English ◽  
...  

Beginning in 1995, segments of the late-run sockeye salmon (Oncorhynchus nerka) stocks from the Fraser River, British Columbia, have initiated upriver spawning migration up to 6 weeks earlier than historical records; and those fish have experienced high rates of en route mortality. We examined the correlations between physiological and energetic status prior to river entry with subsequent migratory performance of individual salmon using telemetry and noninvasive biopsies for Adams–Thompson–Shuswap (Adams) and Weaver–Harrison (W–H) stocks. Salmon that failed to reach the river were characterized by a tendency to have elevated levels of chronic and acute stress indicators. For one stock of fish (i.e., Adams) that entered the river, those that died before reaching spawning grounds were individuals with low gross somatic energy. Furthermore, females tended to have elevated plasma estradiol levels. When contrasting fish with different behaviours and fates, fish that did not hold in the estuary and subsequently died tended to have less energy than fish that held and reached spawning areas. Females from the former group also had higher 11-ketotestosterone and estradiol levels relative to those from the later group. These data suggest that differences in physiological and energetic status may be associated with high en route mortality in late-run sockeye salmon.


1933 ◽  
Vol 8 (1) ◽  
pp. 345-355
Author(s):  
R. E. FOERSTER

Eggs spawned naturally by 3,883 females in 1925 were estimated as amounting to 17,470,000. Approximately 12,500 fry (0.07% of eggs) migrated to sea in 1926, 183,272 yearlings (1.05%) in 1927, and 1,722 two-year-olds (0.01%) in 1928, making 1.13% in all. Returning fish consisted of no three-year (32 group), 4,463 four-year (42 group), and 1,112 five-year fish (no 52 group, all being of the 53 group). None of the fish was reported returning to other spawning areas.


1982 ◽  
Vol 39 (11) ◽  
pp. 1444-1452 ◽  
Author(s):  
Randall M. Peterman

A method is derived to determine whether ocean abundance of a salmon stock affects either the survival rate between particular ages or the proportion of the ocean population which migrates back to freshwater spawning areas. The approach, similar to Fredin's smolt indices method, uses data on brood-year contributions to adult returns in successive years. Survival rate and proportion maturing are found to be independent of stock abundance after age 3, except in Naknek River sockeye (Oncorhynchus nerka) data. In cases such as Babine Lake sockeye salmon, where nonlinearity has been identified previously in the relation between smolt abundance and total adult returns, this lack of density dependence in the older ages means that the mortality processes which cause that nonlinearity act early in smolt life. The relations between abundance of adult returns of age n in year t and returns of age n + 1 from the same brood class in year t + 1 are useful as preseason forecasting techniques. The method derived here, which uses logarithms of abundances, improves upon the existing forecasting method. Deviations from the relation between abundances of brood-year returns can in some cases be explained by smolt weight, which is shown to affect mean age at return.Key words: salmon age structure, marine survival, age-at-return, smolt weight, preseason forecasting


1980 ◽  
Vol 37 (7) ◽  
pp. 1093-1100 ◽  
Author(s):  
W. S. Grant ◽  
F. M. Utter

The distributions of biochemical genetic variants were used to examine the genetic relationships among populations of walleye pollock, Theragra chalcogramma, located in the southeastern Bering Sea and the Gulf of Alaska. Enzymatic proteins in tissue samples of fish collected from 14 locations were assayed for electrophoretically detectable variants. Twenty-eight loci were tentatively identified, 8 (28%) of which were polymorphic. Only two loci, ME-2 and 6PG, had variants in great enough frequencies to be of use in distinguishing populations. Significant differences between regions were detected using a log-likelihood test for heterogeneity. Variation in allelic frequencies within each region was minimal. Cluster analysis of genetic similarities between sample pairs revealed two major clusters roughly corresponding to the Bering Sea and the Gulf of Alaska. Our biochemical genetic data suggest that there are no distinct stocks within the southeastern Bering Sea nor within the Gulf of Alaska, but that there are minor genetic differences between fish in these two regions.Key words: Walleye pollock, Theragra chalcogramma; biochemical genetic variation, population structure, eastern Bering Sea, Gulf of Alaska, starch gel electrophoresis


1964 ◽  
Vol 21 (3) ◽  
pp. 485-504 ◽  
Author(s):  
Wilbur L. Hartman ◽  
Robert F. Raleigh

The degree of preference of sockeye salmon (Oncorhynchus nerka) for spawning in specific tributaries to Brooks and Karluk Lakes, Alaska, was studied in 1960 and 1961. Adult sockeye salmon begin to congregate around stream mouths soon after entering these lakes. At Brooks Lake, groups of fish were seined from various stream mouths and marked with distinctive tag color combinations. One group of tagged fish from each seine haul was released back into the original donor congregation as a control, and one or more groups were transported and released into congregations around other tributary mouths. Strength of tributary preference was determined by comparing the number of fish from each group distributed on the various spawning grounds. Eighty-three per cent of the 958 fish tagged were recovered at weirs and on stream and lake surveys. Distribution to spawning areas of sockeye salmon in control and transported groups was virtually identical. The study at Brooks Lake was followed by a study at Karluk Lake to explore further the strength of tributary preference. Very few sockeye salmon experimentally prevented from entering their preferred tributary chose an alternative spawning area. Most continued to attempt to enter their blocked tributary until death. A final study at Karluk Lake confirmed the fact that sockeye salmon entering the lake were predisposed to spawn in a particular tributary and could not be conditioned to enter an alternative tributary. We conclude that sockeye salmon are indeed homing to particular tributaries in these small lakes. The biological and management implications of these findings are discussed.


1989 ◽  
Vol 46 (1) ◽  
pp. 149-158 ◽  
Author(s):  
Chris J. Foote ◽  
Chris C. Wood ◽  
Ruth E. Withler

Twenty-three anadromous (sockeye salmon) and nonanadromous (kokanee) Oncorhynchus nerka populations were sampled from throughout British Columbia and examined electrophoretically at three to five polymorphic loci to test whether the forms represent distinct genetic lineages or whether they are polyphyletic. Sockeye and kokanee which spawn sympatrically in three different lake systems were also examined to determine whether the two forms belong to a single panmictic population. Our results support the hypothesis that sockeye and kokanee are polyphyletic. No genetic characters were found by which the forms could be separated consistently. Greater differences exist among O. nerka populations from different drainages than between sockeye and kokanee forms. Sympatric sockeye and kokanee were significantly different in all systems examined, demonstrating that genetic differences can persist in the absence of geographic barriers to gene flow. While sympatric sockeye and kokanee were genetically divergent, they showed greater genetic similarity to one another (in allele frequency and/or allele types) than they did to their own forms in neighbouring lakes. We argue that this genetic similarity between sympatric forms is the result of sympatric divergence of sockeye and kokanee.


1976 ◽  
Vol 33 (1) ◽  
pp. 186-188 ◽  
Author(s):  
Roger S. Grischkowsky ◽  
Donald F. Amend

Infectious hematopoietic necrosis (IHN) virus is reported for the first time in Alaskan sockeye salmon (Oncorhynchus nerka). The virus was isolated from moribund juveniles at Kitoi Bay and from adults of 16 spawning stocks throughout the Bristol Bay, Kodiak Island, Cook Inlet, and the Gulf of Alaska areas.


Author(s):  
Thomas P. Quinn ◽  
George R. Pess ◽  
Ben J.G. Sutherland ◽  
Samuel J. Brenkman ◽  
Ruth E. Withler ◽  
...  

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