Determinants of stream life, spawning efficiency, and spawning habitat in pink salmon in the Auke Lake system, Alaska

1997 ◽  
Vol 54 (1) ◽  
pp. 96-104 ◽  
Author(s):  
M Fukushima ◽  
W W Smoker
Keyword(s):  
Linear Models ◽  
Pink Salmon ◽  
Stream Temperature ◽  
Oncorhynchus Gorbuscha ◽  
Spawning Habitat ◽  
Stream Discharge ◽  
Lake System ◽  
Inlet Stream ◽  
Lake Outlet ◽  
Outlet Stream

Variation in stream life, spawning efficiency, and spawning habitat among adult pink salmon (Oncorhynchus gorbuscha) in the Auke Lake system, southeastern Alaska, was best explained by stream discharge, stream temperature, and a combination of stream temperature and discharge. We estimated these attributes of female pink salmon spawners in samples of daily cohorts tagged as they entered fresh water and used generalized linear models to analyze variation in the attributes with respect to environmental factors. Spawners varied in stream life (5-11 days), spawning efficiency (30-70% of females in daily entry cohorts retained less than 500 eggs at death), and spawning habitat (30-70% spawned in the lake outlet stream rather than the lake inlet stream). Observed variation of habitat (proportionately more use of the cooler inlet stream early in the spawning season when stream temperatures are warm and development is rapid) would contribute to synchronicity of fry emigration, which is known to be positively correlated with subsequent survival in Auke Lake pink salmon.

Results for Three Generations from Transfers of Pink Salmon (Oncorhynchus gorbuscha) Spawn to the Qualicum River in 1963 and 1964

1971 ◽  
Vol 28 (5) ◽  
pp. 647-654 ◽  
Author(s):  
C. E. Walker ◽  
D. B. Lister
Keyword(s):  
Chum Salmon ◽  
Pink Salmon ◽  
Stream Temperature ◽  
Rate Of Return ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Three Generations ◽  
Salmon Eggs ◽  
Bear River

Transfers of pink salmon (Oncorhynchus gorbuscha) eggs were made to the Qualicum River in two years, utilizing 5.79 million eggs from Cheakamus River stock in 1963 and 6.85 million eggs from Bear River stock in 1964. Adult returns to the Qualicum River were 100 spawners in 1965, 1967, and 1969; 11,940 in 1966; 3000 in 1968; and 300 in 1970. Differences between the odd- and even-year plants were noted in times of egg-take (equivalent to time of spawning of donor stock), incubation, and fry emigration, lengths of emigrating fry, possibility of losses through predation by herring on estuarine fry, and direction of orientation to the recipient (Qualicum River) stream. Pronounced differences between donor stock in rate of return are thought to be primarily related to differences in spawning times and stream temperature. The decrease in numbers of adults in the even-year generation may have been due to lower freshwater survival during incubation as a result of suspected superimposition of chum salmon on the earlier deposited pink salmon eggs; the loss was estimated to be in the order of 46%.

Estimation of eggs lost from superimposed pink salmon (Oncorhynchus gorbuscha) redds

1998 ◽  
Vol 55 (3) ◽  
pp. 618-625 ◽  
Author(s):  
M Fukushima ◽  
T J Quinn ◽  
W W Smoker
Keyword(s):  
Maximum Likelihood ◽  
Pink Salmon ◽  
Oncorhynchus Gorbuscha ◽  
Pink Salmon Oncorhynchus Gorbuscha ◽  
Male And Female ◽  
Stream Discharge ◽  
Density Dependent Mortality ◽  
Repeated Use ◽  
Redd Superimposition ◽  
Dependent Mortality

This study investigated whether repeated use of limited spawning grounds (i.e., redd superimposition) by pink salmon (Oncorhynchus gorbuscha) can cause density-dependent mortality. Loss of eggs from part of Auke Creek, Alaska, was estimated from a series of mark-recapture experiments and maximum likelihood models. The number of eggs lost per day during the 5-week spawning season and for 2 weeks afterward was roughly proportional to spawner abundance and weakly related to stream discharge. Freshets after cessation of spawning induced negligible egg loss. The maximum daily egg loss estimated by one model was 398 000 eggs (80% CI = 267 000 - 1 581 000) or equivalently a loss of about 300 female spawners when the daily spawner abundance (both male and female) in the study area was at most 1000.

A hump-shaped relationship between migration distance and adult pink salmon morphology suggests interactive effects of migration costs and bear predation

2016 ◽  
Vol 73 (3) ◽  
pp. 427-435 ◽  
Author(s):  
Genki Sahashi ◽  
Taku Yoshiyama
Keyword(s):  
Body Shape ◽  
Pink Salmon ◽  
Interactive Effects ◽  
Head Size ◽  
Oncorhynchus Gorbuscha ◽  
Spawning Habitat ◽  
Selective Predation ◽  
Body Depth ◽  
Shape Selective ◽  
Migration Costs

We examined the relationship between environmental factors of a spawning habitat and body shape at maturity in 16 pink salmon (Oncorhynchus gorbuscha) populations. The divergence vector (indicator of body depth and head size development) in both sexes was significantly correlated with distance from the sea and was described by a hump-shaped relationship. An exaggerated body shape was most developed at mid-distance from the sea and less developed both near and far from the sea. The observed frequency of bears decreased significantly with distance from the sea, implying that bear predation on salmon is most intense near the sea. Therefore, our results imply that shape-selective predation by bears affects the shape of pink salmon in rivers where the spawning habitat is near the sea and that migration costs inhibit development of an exaggerated body depth and head size in salmon in rivers where the spawning habitat is far from the sea.

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.

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