Variability in Aerial Counts of Spawning Salmon

1961 ◽  
Vol 18 (3) ◽  
pp. 337-348 ◽  
Author(s):  
Donald E. Bevan
Keyword(s):  
Experimental Design ◽  
Population Size ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Spawning Ground ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Kodiak Island ◽  
Aerial Surveys ◽  
The Relationship ◽  
Made In

A study of spawning ground surveys for pink salmon (Oncorhynchus gorbuscha) was made in two streams on Kodiak Island. An experimental design is described which permits replication of observers' counts of spawning salmon. The variance in an observer's estimate was found to be proportionate to the size of the estimate. The experiments indicated that an observer will detect differences in population size of plus or minus 50%. The relationship between counts of one observer and another changes within different streams, but within each river the observations of one observer were correlated with those of another. The results of the experiments are summarized in recommendations for aerial surveys of spawning salmon.

Intrapopulation Variation in the Breeding of Male Pink Salmon (Oncorhynchus gorbuscha) from a Lake Superior Tributary

1990 ◽  
Vol 47 (1) ◽  
pp. 174-179 ◽  
Author(s):  
Douglas B. Noltie
Keyword(s):  
Lake Superior ◽  
Pink Salmon ◽  
Life History Strategies ◽  
Oncorhynchus Gorbuscha ◽  
Breeding Ground ◽  
Spawning Ground ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Intrapopulation Variation ◽  
Morphological Studies ◽  
Proximate Factors

Studies of breeding pink salmon (Oncorhynchus gorbuscha) from the Carp River, eastern Lake Superior, indicate that males seek fertilizations using two behavioural tactics. In 1985, a large run resulted in high breeding ground densities. During this run, males that resembled females were seen seeking fertilizations by sneaking rather than by competing for proximity to females. Morphological studies in 1985 confirmed the presence of males resembling females, their secondary sexual characters (hump height) being relatively less developed than in typical males. Although in poorer condition, such female-like males were reproductively mature, had returned to spawn at ages typical for this population, and had committed biomass to gonad no differently than had typical males. Furthermore, their spawning performance did not differ from typical males, as assessed both by the amount of gonad they retained unspawned at death and by their spawning ground life expectancies. In contrast, males attempting to sneak fertilizations were not observed during the small 1984 run when densities were low and males were generally in better condition than in 1985. Together, these results indicate that male pink salmon exhibit alternative breeding tactics. However, the demonstration of these tactics appears linked more to proximate factors (density and condition) than to divergent life history strategies as in other salmonid species.

Number of Circuli and Time of Annulus Formation on Scales of Pink Salmon (Oncorhynchus gorbuscha)

1966 ◽  
Vol 23 (5) ◽  
pp. 747-756 ◽  
Author(s):  
Roger E. Pearson
Keyword(s):  
North America ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Pink Salmon ◽  
Fork Length ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Annulus Formation ◽  
Relationship Of ◽  
The Relationship

Mean numbers of circuli on scales of juvenile pink salmon collected along the coast of North America in 1964 increased from 1.7 on June 23 to 17.4 on September 10. On scales of adults collected from the eastern North Pacific Ocean from 1962 to 1965, mean numbers of circuli ranged from 24.1 on January 23 (1964) to 46.9 on September 2 (1962). The fork length at time of scale formation was approximately 60 mm. Mean fork length increased with the total number of circuli. The relationship of fork length to number of scale circuli showed some variation between stocks. The winter ring was present or was being formed on the majority of scales taken in late January. The development of the annulus varied considerably among individual fish.

Efficiency of Natural Propagation of the Pink Salmon (Oncorhynchus gorbuscha) in McClinton Creek, Masset Inlet, B.C.

1948 ◽  
Vol 7b (5) ◽  
pp. 224-236 ◽  
Author(s):  
A. L. Pritchard
Keyword(s):  
Pink Salmon ◽  
Climatic Conditions ◽  
Spawning Migration ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Egg Deposition ◽  
Number Of Factors ◽  
Biological Environment ◽  
Relationship Of ◽  
The Relationship

Through the medium of specially-designed counting fences, records have been maintained of the adult pink salmon, Oncorhynchus gorbuscha, spawning in McClinton creek, Masset inlet, B.C. from 1930 to 1942, of the eggs available for deposition each season and of the fry resulting from these eggs. A loss of 76.2 to 93.1 per cent of the potential egg deposition occurs between the time of upstream spawning migration and the egress of the fry to sea. This mortality is assigned to a number of factors, some of which are briefly discussed. Within certain limits and under reasonably uniform climatic conditions smaller egg depositions provide greater efficiencies of hatch (percentage relationship of numbers of fry migrants to potential egg deposition). There thus appears a tendency toward rebuilding the run, herein termed "resilience," and believed to be closely bound up with the relationship between the fish and its physical and biological environment.

Outbreeding effect on embryo development in hybrids of allopatric pink salmon (Oncorhynchus gorbuscha) populations, a potential consequence of stock translocation

Aquaculture ◽  
2007 ◽  
Vol 272 ◽  
pp. S152-S160 ◽  
Author(s):  
Ivan A. Wang ◽  
Sara E. Gilk ◽  
William W. Smoker ◽  
Anthony J. Gharrett
Keyword(s):  
Embryo Development ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Potential Consequence ◽  
Pink Salmon Oncorhynchus Gorbuscha

Juvenile Pacific Sandfish, Trichodon trichodon, Associated with Pink Salmon, Oncorhynchus gorbuscha, Fry in the Nearshore Area, Southeastern Alaska

Copeia ◽  
1983 ◽  
Vol 1983 (2) ◽  
pp. 549 ◽  
Author(s):  
Jack E. Bailey ◽  
Bruce L. Wing ◽  
Joyce H. Landingham
Keyword(s):  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Nearshore Area

Supplementary Checks on the Scales of Pink Salmon (Oncorhynchus gorbuscha) and Chum Salmon (O. keta)

1965 ◽  
Vol 22 (6) ◽  
pp. 1477-1489 ◽  
Author(s):  
H. T. Bilton ◽  
W. E. Ricker
Keyword(s):  
British Columbia ◽  
Chum Salmon ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Commercial Fisheries ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Clear Cut ◽  
Second Year Of Life ◽  
Second Year ◽  
Similar Incidence

Among 159 central British Columbia pink salmon that had been marked by removal of two fins as fry and had been recovered in commercial fisheries after one winter in the sea, the scales of about one-third showed a supplementary or "false" check near the centre of the scale, in addition to the single clear-cut annulus. This evidence from fish of known age confirms the prevailing opinion that such extra checks do not represent annuli, hence that the fish bearing them are in their second year of life rather than their third. Unmarked pink salmon from the same area, and some from southern British Columbia, had a generally similar incidence of supplementary checks. In both marked and unmarked fish the supplementary checks varied in distinctness from faint to quite clear. In a sample of scales of 14 double-fin marked chum salmon which were known to be in their 4th year, all fish had the expected 3 annuli, and 12 fish had a supplementary check inside the first annulus.

Sign in / Sign up

Export Citation Format

Share Document