On the Distribution of Young Sockeye Salmon (Oncorhynchus nerka) in Babine and Nilkitkwa Lakes, B.C.

1956 ◽  
Vol 13 (5) ◽  
pp. 695-708 ◽  
Author(s):  
W. E. Johnson

Babine Lake and connected Nilkitkwa Lake, a total lake area of 174 square miles, provide nursery facilities for progeny of the largest sockeye salmon run to the Skeena River in northern British Columbia.Based on catch per unit of fishing effort, tow-net collections in August and October, 1955, indicate that at least 67%, and possibly as much as 88%, of the total age 0 sockeye population of these lakes (estimated as 50 to 60 million) was concentrated in Nilkitkwa Lake and the North Arm of Babine Lake: that is, in 11.4% of the total lake area. Mean size of young sockeye in these areas of concentration was much smaller than in the sparsely populated remainder of Babine Lake.This unequal distribution of young sockeye, and resulting inefficient utilization of the lake nursery facilities, is apparently a result of the distribution of the spawning parent population and a limited dispersal of young sockeye from their points of entrance into the lake as fry.

1985 ◽  
Vol 63 (12) ◽  
pp. 2924-2932 ◽  
Author(s):  
R. E. Withler

Allozyme variation at the Ldh-4 locus was surveyed in 66 populations of sockeye salmon (Oncorhynchus nerka) over the North American range of this species. Two alleles, Ldh-4100 and Ldh-4115, were present in populations over the species range, but frequencies of the Ldh-4115 allele exceeding 5% were restricted to some populations in northern British Columbia and Alaska. Ldh-485 present at frequencies less than 10%, was virtually confined to populations of the Skeena River drainage. Likelihood ratio analysis revealed significant variation in Ldh-4 allelic frequencies among major geographic regions, among smaller areas within regions, and among populations within the Nass and Stikine River drainages. Selective and zoogeographic factors which may explain the distribution of the Ldh-4115 allele in North American sockeye populations are discussed.


Author(s):  
Iin Ika Wahyuni ◽  
Anhar Solichin ◽  
Suradi Wijaya Saputra

 Salah satu potensi perikanan di perairan Brebes dan Tegal adalah Udang Putih yang terancam kelestariannya akibat meningkatnya penangkapan dengan Jaring Arad. Tujuan penelitian ini untuk mengetahui aspek biologi udang P. indicus dan status sumberdayanya, seperti komposisi hasil tangkapan, struktur ukuran, sifat pertumbuhan, dan aspek reproduksi. Metode penelitian yang digunakan yaitu metode survei. Sampel udang diambil 100% dari total hasil tangkapan tiap perahu karena hasil tangkapan kurang dari 100 ekor. Pengambilan sampel enam kali dari Juli-Desember 2016. Tempat pengambilan sampel di TPI Kluwut, Kaliwlingi, Larangan dan Surodadi. Hasil penelitian nilai L50%P. indicus di sebelah utara Brebes dan Tegal memiliki panjang total 84 mm dan 85 mm, nilai ½ L∞ yaitu 97 mm (jantan) dan 121 mm (betina). L50% < ½ L∞ berarti ukuran udang yang tertangkap masih kecil sehingga dikhawatirkan terjadinya growth overfishing. Sifat pertumbuhan udang jantan dan betina di Brebes yaitu isometrik (b=2,98) dan alometrik negatif (b=2,86), di Tegal yaitu alometrik positif (b= 3,43) dan isometrik (b= 3,02). Nilai faktor kondisi P. indicus di Brebes 1,63 (jantan) dan 1,59 (betina), sedangkan di Tegal 1,81 (jantan) dan 1,57 (betina). Perbandingan nisbah kelamin P. indicus di Brebes 1: 4,4 dan di Tegal 1: 2,9. Status tingkat pemanfaatan sumberdaya udang P. indicus di sebelah utara Brebes dan Tegal perlu penyempurnaan untuk memenuhi syarat perikanan yang berkelanjutan. One of the potential fishery in the Brebes and Tegal waters is P. Indicus shrimp that has been threatened by increasing fishing effort of Arad net. The purpose of this research to know biological aspects of P. indicus and resources status, such as composition of catch, size of structure, growth, and reproduction aspects. The method used is survey method. Shrimp samples were taken at random 10% of the total catch per boat. Sampling six times from July to December 2016. The sampling at TPI Kluwut, TPI Kaliwlingi, TPI Larangan and TPI Surodadi. The results of research L50% value of P. indicus in north Brebes and Tegal has 84 mm and 85 mm TL, ½ L∞ are 97 mm (males) and 121 mm (females). L50% <½ L∞ mean size of shrimp caught are ssmall to worry about the occurrence of growth overfishing. The growth of males and females shrimp in Brebes are isometric (b = 2.98) and negative allometric (b = 2.86), in Tegal growth of males and females are positive allometrik (b = 3.43) and isometric (b = 3.02). Condition factor P. indicus in Brebes are 1.63 (males) and 1.59 (females), whereas in Tegal are 1.81 (males) and 1.57 (females). Sex ratio P. indicus in Brebes 1: 4.4 and in Tegal 1: 2.9. Status of the level of resource P. indicus need improvement to qualify sustainable fisheries.  


1975 ◽  
Vol 32 (2) ◽  
pp. 233-242 ◽  
Author(s):  
C. Groot ◽  
K. Simpson ◽  
I. Todd ◽  
P. D. Murray ◽  
G. A. Buxton

Movements of adult sockeye salmon (Oncorhynchus nerka) entering the Skeena River were examined in 1969 and 1970 by ultrasonic tracking methods. Fifteen of 18 sockeye released in the lower river seemed to move passively in and out with flood and ebb streams. Two fish moved upstream independent of tides and one salmon swam against ebb and flood currents. Ground speeds in both years of operation were 1.6 km/h during rising and 2.1 km/h during falling tides, causing the fish to be transported downstream by about 3 km per tidal cycle. Three salmon released outside the river mouth in salt water also seemed to ride the tidal flows passively. Ground speeds during ebb (3.6 km/h) were again greater than during flood (2.0 km/h), indicating a net offshore movement. We conclude that these passive movements are not an artifact but that sockeye salmon normally slow down or pause upon reaching the "home river" and drift for a period in tidal currents in the estuary and river mouth before migrating upstream.


2004 ◽  
Vol 61 (7) ◽  
pp. 1235-1246 ◽  
Author(s):  
Irene Gregory-Eaves ◽  
Bruce P Finney ◽  
Marianne SV Douglas ◽  
John P Smol

Historical and paleolimnological studies have demonstrated that environmental changes in the North Pacific can strongly affect sockeye salmon (Oncorhynchus nerka) abundances. Whether these marine shifts would be influential on sockeye salmon from all lake types, however, has not yet been studied. This study represents the first paleolimnological analysis of past sockeye salmon population dynamics in a stained nursery lake (Packers Lake, Alaska). We adopted a multiproxy approach to determine whether salmon-derived nutrients (inferred from δ15N) would be available for algal uptake (inferred from the diatom species responses) in this stained lake, as high concentrations of humics and iron are known to sequester phosphorus. The strong degree of coherency between δ15N and diatoms, however, suggests that salmon-derived nutrients were bioavailable and enhanced productivity. Overall, our indicators responded to changes in sockeye salmon abundances and volcanic ashfalls over the past ∼500 years. In a section of the core unaffected by tephras (AD ∼1770–1882), our record suggests that the number of sockeye salmon spawners fluctuated widely. Comparison of temporal shifts in inferred sockeye salmon abundances from Packers Lake with other clearwater nursery lakes reveals a broadly consistent pattern, likely influenced by past climatic changes.


1998 ◽  
Vol 55 (4) ◽  
pp. 937-948 ◽  
Author(s):  
D W Welch ◽  
Y Ishida ◽  
K Nagasawa

Ocean surveys show that extremely sharp thermal boundaries have limited the distribution of sockeye salmon (Oncorhynchus nerka) in the Pacific Ocean and adjacent seas over the past 40 years. These limits are expressed as a step function, with the temperature defining the position of the thermal limit varying between months in an annual cycle. The sharpness of the edge, the different temperatures that define the position of the edge in different months of the year, and the subtle variations in temperature with area or decade for a given month probably all occur because temperature-dependent metabolic rates exceed energy intake from feeding over large regions of otherwise acceptable habitat in the North Pacific. At current rates of greenhouse gas emissions, predicted temperature increases under a doubled CO2 climate are large enough to shift the position of the thermal limits into the Bering Sea by the middle of the next century. Such an increase would potentially exclude sockeye salmon from the entire Pacific Ocean and severely restrict the overall area of the marine environment that would support growth.


2019 ◽  
Vol 198 ◽  
pp. 3-18
Author(s):  
E. V. Golub’ ◽  
A. P. Golub’

Data on traumatization of sockeye salmon Oncorhynchus nerka spawners in the Meynypil’gyn lake-river system by lampreys are presented on results of observations in 1998– 2018. Features and localization of injuries are described comparing the injuries of males and females and biological parameters of fish with and without the injuries. In the Meynypil’gyn lake-river system, relative to other areas of Russian Far East, the portion of fish with injuries from lampreys is medium for sockeye salmon, and low for pink salmon Oncorhynchus gorbuscha and charr Salvеlinus malma. Judging by size of the wounds, the injuries were caused mostly by arctic lamprey Entosphenus tridentatus. Generally, about 68 % of sockeye spawners were attacked by lampreys during their pre-spawning migrations just before entering the fresh waters, but the percentage (P) depends on length (L) of fish: P = 1.2026 . L + 1.2192 (R2 = 0.879). So, the portion of injured fish increased from 2.7 % for the sockeye producers with length < 500 mm to 31.2 % for those with length 671–680 mm. Mean size and weight of the male and female sockeye spawners with traces of lampreys were statistically significantly higher than these parameters for the fish without injuries. The males injured by lampreys were larger than the males without injures in 18 mm and 295 g, the females — in 5 mm and 80 g, on average. Sockeye females had weaker and less numerous damages, so their portion among the fish with 1 injury was 45.4 %, among the fish with 2 injuries — 42.9 %, among the fish with 3 or more injures — 37.0 %. Besides, mean size of the injured sockeye increased with a number of injures and for the groups with 1, 2, and 3 or more injures it was for females: 604, 608, and 613 mm, for males: 655, 667, and 674 mm, respectively. Such dependencies of alive fish traumatization on their size are caused by higher mortality of small fish after lampreys attacks. There is concluded that arctic lamprey affects significantly on sexual and size composition of sockeye spawners in the Meynypil’gyn lake-river system providing selection of fish with larger size and weight, in particular males.


1990 ◽  
Vol 47 (12) ◽  
pp. 2380-2389 ◽  
Author(s):  
E. Garnick ◽  
L. Margolis

Each of four helminth parasite species, including the cestodes Eubothrium salvelini, Diphyllobothrium dendriticum, and Proteocephalus sp. and the nematode Philonema oncorhynchi, was found to influence the orientation of seaward-migrating sockeye salmon (Oncorhynchus nerka) smolts from the Great Central Lake area, Vancouver Island, British Columbia. Smolts placed in circular tanks were allowed to exit into evenly spaced bucket traps, and fish from five such runs were measured, sexed, and examined for the presence of parasites. Fish were categorized on the basis of infection status ("+" vs. "−") for each of the four parasite species found. The +/− groups did not differ for any of the parasite categories with respect to either bucket distributions or overall orientation directions. However, "−" groups did exhibit consistently greater departure from random distribution than their "+" counterparts. This finding suggests interference of parasites with smolt orientation, which could in turn have important implications for smolt survival. This finding also suggests that parasite infection may account to some extent for the considerable variability observed in the migratory behaviour of smolts.


1969 ◽  
Vol 26 (1) ◽  
pp. 15-19 ◽  
Author(s):  
H. O. Hodgins ◽  
W. E. Ames ◽  
F. M. Utter

Three phenotypes of lactate dehydrogenase (LDH) isozymes were found in sera of sockeye salmon (Oncorhynchus nerka), presumably representing B′B′, B′B, and BB genotypes. No association was obvious between LDH phenotype of sera and sex or total body length.Of 1006 sera from Asian, Bristol Bay, and Gulf of Alaska stocks, 826 were B′B′ and 180 were B′B or BB. Of 591 sera from Washington and British Columbia stocks, 589 were B′B′ and 2 were B′B; both of the B-allele phenotypes were found in fish captured at the Skeena River in northern British Columbia. These findings suggested that LDH isozymes should be useful in studies on ocean distribution of sockeye salmon and in characterizing certain Asian and Alaskan sockeye salmon populations.


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