The timing of adult sockeye salmon migration into fresh water: adaptations by populations to prevailing thermal regimes

2002 ◽  
Vol 80 (3) ◽  
pp. 542-555 ◽  
Author(s):  
Sayre Hodgson ◽  
Thomas P Quinn

Anadromous fishes migrate to sea, apparently to take advantage of growing conditions, and return to fresh water to spawn. Despite favorable growing conditions at sea in summer, some populations leave the ocean in spring, many months prior to spawning. We hypothesized that this premature migration is a consequence of the fish having to avoid stressful summer temperatures in order to access certain suitable areas for spawning in the fall. We tested this idea in sockeye salmon, Oncorhynchus nerka, by compiling data on the timing of migration and spawning and the freshwater temperature regime along the migration route in populations throughout the species' North American range. The timing of migration varied among populations and was primarily related to temperature regime during migration and the timing of spawning. When temperatures were moderate (<19°C), sockeye salmon tended to migrate to the vicinity of the spawning grounds about 1 month prior to spawning, regardless of the length of the freshwater migration. However, populations on whose migration route the average temperature exceeded 19°C displayed two basic patterns. Some populations entered fresh water prior to the warmest period, months before spawning, whereas others migrated after the period of highest temperatures had occurred.

2016 ◽  
Vol 184 (1) ◽  
pp. 23-40
Author(s):  
Oleg M. Zaporozhets ◽  
Galina V. Zaporozhets ◽  
Zhanna Kh. Zorbidi

Dynamics of biological parameters for adults of chum, sockeye, pink, coho, and chinook salmons in the rivers of the Avachinsky Bay is analyzed. There is shown for three populations of sockeye salmon that general age of the returned adults correlates positively with duration of their fresh-water life but negatively with timing of their approach for spawning. Tendency to decreasing of weight is revealed for chinook females, but weight of their males is stable. Dynamics of weight and timing of spawning run is significantly different for pink and chum salmons of the rivers Avacha and Nalycheva. Weight of coho females has negative trend, in spite of stable fecundity and age of return.


2011 ◽  
Vol 112 (1-2) ◽  
pp. 85-95 ◽  
Author(s):  
Marika Kirstin Gale ◽  
Scott G. Hinch ◽  
Erika J. Eliason ◽  
Steven J. Cooke ◽  
David A. Patterson

1958 ◽  
Vol 36 (8) ◽  
pp. 783-791 ◽  
Author(s):  
D. R. Idler ◽  
H. Tsuyuki

Physical measurements have been made on all major organs and tissues of a pure race of migrating adult Oncorhynchus nerka. The data show that the population was sufficiently uniform in size that average weights and measurements performed on fish taken at three locations on the migration route quite accurately represented a standard fish of both sexes. The results will enable chemical analyses to be interpreted as changes in absolute amounts of a given tissue component rather than only on a percentage basis. The merits of this approach to an evaluation of changes in migrating salmon is demonstrated by the magnitude of the weight changes in many tissues during the 715-mile migration. A standard male lost only 11% of its body flesh whereas a standard female lost 30%. The alimentary tract decreased to one sixth of the initial weight. The milt increased by 51% w hile the roe increased by 272%. Thus, it is apparent that percentage composition data cannot show quantitative changes in a fish as it moves up the river. The results are discussed in relation to the findings of others on Salmonidae.Plasma cholesterol, magnesium, calcium, sulphate, and urea levels were measured on pooled blood samples from the 216 fish.


1960 ◽  
Vol 17 (3) ◽  
pp. 295-322 ◽  
Author(s):  
Bertha Baggerman

In juvenile Pacific salmon the changes in salinity preference associated with seaward migration and thyroid activity were studied and used as criteria for the induction of the physiological condition required for migration (migration-disposition).Four species of Oncorhynchus (chum, pink, coho and sockeye) changed preference from fresh to salt water at the onset of seaward migration and maintained this preference throughout the migration season. At the end of this migration period coho and sockeye salmon changed preference from salt to fresh water if retained in fresh water, indicating a re-adaptation to this medium in which they may survive for several years. Chum and pink fry did not show this change in preference and usually died when retained in fresh water. They were apparently unable to re-adapt to this environment.The increasing day length in spring controls the time at which the change in preference from fresh to salt water takes place, and is thus involved in timing the induction of migration-disposition.The photoperiod seems to affect particularly the pituitary-thyroid system. Thyroid activity increases shortly before the onset of migration, remains high during the migration season, and decreases towards its end. The level of thyroid hormone in the blood influences salinity tolerance and preference and, thus, the induction of migration-disposition. Metamorphosis, osmotic "stress" and iodine content of the water may have some additional effect on thyroid activity, but are not the only factors responsible for thyroid hyperactivity during migration.Animals in which migration-disposition has been induced are thought to have become susceptible to appropriate external stimuli "releasing" migration.


2009 ◽  
Vol 87 (6) ◽  
pp. 480-490 ◽  
Author(s):  
M. R. Donaldson ◽  
S. J. Cooke ◽  
D. A. Patterson ◽  
S. G. Hinch ◽  
D. Robichaud ◽  
...  

The objective of this study was to combine radio telemetry with individual thermal loggers to assess the extent to which adult migrating sockeye salmon ( Oncorhynchus nerka (Walbaum in Artedi, 1792)) behaviourally thermoregulate during their migration through the Fraser River mainstem, British Columbia. The Fraser mainstem represents a region of the migration route that contains some of the highest mean temperatures encountered by sockeye salmon during their life history. We found that throughout the study area, individual sockeye salmon body temperatures occasionally deviated from ambient temperatures (ΔT), yet individuals maintained a ΔT of –1 °C or cooler for only 5% of their migration through the study region. There were moderate mean deviations of ΔT in two segments that are known to contain thermally stratified waters. In one of the study segments with the greatest ΔT, mean body temperatures decreased as river temperatures increased and ΔT became increasingly positive with higher river discharge rates, but these relationships were not observed in any of the other study segments. No relationship existed between ΔT and migration rate. While periodic associations with cool water were evident, mean body temperatures were not significantly different than mean river temperatures throughout the lower Fraser mainstem. This finding raises further conservation concerns for vulnerable Fraser River sockeye stocks that are predicted to encounter increasing peak summer river temperatures in the coming decades.


1979 ◽  
Vol 51 (1) ◽  
pp. 197-209
Author(s):  
Seppo Pulli ◽  
P. M. A. Tigerstedt ◽  
Osmo Kara

Trials with maize varieties from various places in the world were started in 1975. In preliminary trials in 1975, 280 varieties were tested. Between 19 and 23 varieties were selected for ordinary variety tests in 1976—78 at the University farm in Siuntio. Weather conditions, particularly average daily temperatures in 1975 were better than the long term averages, and in 1976—78 far below the average growing conditions. Dry matter yields of the seven harvested silage varieties in 1975 varied between 5.8 and 11.5 tons/ha. In 1976—78 the variation in DM yields was 3.8—8.0 tons/ha among 19—23 varieties. In 1975, 44 varieties out of 280 produced mature seed. Only one variety matured in 1978, but none in 1976—77. The developmental stage of silage maize is primarily determined by ear percentage and secondarily by DM %. In 1975 the average ear % of seven varieties was 49.1 %, in 1978 18.1 % and in 1976—77 only 4.0—5.7 % in DM. As a result of the variety tests promising varieties from Yugoslavia, France and Germany could be found. It can be concluded from the long term temperature data that with very early hybrid varieties a mature grain yield can be harvested twice in ten years. Good quality silage material can be harvested six times in ten years and a satisfactory crop can be obtained eight times in then years. The limiting factor for the growth and development of maize in Finland is the low average temperature of the growing season. Important but less significant is the length of the vegetative period, which is determined by the first killing frost in the fall. The temperature deficit is particularly critical at the beginning of the growing season.


Author(s):  
Lucieta Guerreiro Martorano ◽  
Wanny Barbosa Soares ◽  
José Reinaldo da Silva Cabral de Moraes ◽  
Werlleson Nascimento ◽  
Lucas Eduardo de Oliveira Aparecido ◽  
...  

Abstract The Tapajós National Forest (Flona Tapajós) has been providing important ecosystem services to society since the creation of this Conservation Unit in the Amazon. This study analyzed two climatic series from Belterra to identify possible effects on the thermal regime in the municipality as a function of the proximity of the Flona Tapajós and the consolidated grain production center in western Pará. Two climatological normal datasets from the National Institute of Meteorology (INMET) were analyzed (1961-1990 and 1981-2010). Analysis of variance was used to compare averages, extremes (minimums and maximums), and thermal amplitudes. Average temperature was 24.6 °C in the first semester (1961-1990) and 25.2 °C (1981-2010), with maximums of 29.4 °C and 29.9 °C, and minimums of 20.6 and 21.2 °C, respectively. There were no statistical differences in these comparisons. In the second semester the averages increased to 25.2 °C and 26.0 °C, and were statistically different, with maximums of 31.2 °C and 31.6 °C and minimums of 20.4 °C and 21.2 °C, indicating different thermal regimes during 1981-2010. Additionally, from October to December the nights were warmer. The Flona Tapajós may have experienced a reduction in provision of ecosystem services, and the increase in minimum temperatures could be associated with grain production activities in the region.


1958 ◽  
Vol 36 (1) ◽  
pp. 783-791 ◽  
Author(s):  
D. R. Idler ◽  
H. Tsuyuki

Physical measurements have been made on all major organs and tissues of a pure race of migrating adult Oncorhynchus nerka. The data show that the population was sufficiently uniform in size that average weights and measurements performed on fish taken at three locations on the migration route quite accurately represented a standard fish of both sexes. The results will enable chemical analyses to be interpreted as changes in absolute amounts of a given tissue component rather than only on a percentage basis. The merits of this approach to an evaluation of changes in migrating salmon is demonstrated by the magnitude of the weight changes in many tissues during the 715-mile migration. A standard male lost only 11% of its body flesh whereas a standard female lost 30%. The alimentary tract decreased to one sixth of the initial weight. The milt increased by 51% w hile the roe increased by 272%. Thus, it is apparent that percentage composition data cannot show quantitative changes in a fish as it moves up the river. The results are discussed in relation to the findings of others on Salmonidae.Plasma cholesterol, magnesium, calcium, sulphate, and urea levels were measured on pooled blood samples from the 216 fish.


Author(s):  
M. B. Ellis

Abstract A description is provided for Leptosphaeria salvinii[Magnaporthe salvinii]. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Oryza sativa. DISEASE: Stem rot of rice (Oryza sativa). Symptoms are usually first seen at the later growth stages. Necrotic lesions begin on the outer leaf sheath near the water line; these spread gradually to the inner sheaths and the stem base. At about maturity lodging may occur and sclerotia will be found within the tissues. Partial sterility is caused and grain becomes light and chalky. Late infection can lead to small tillers but whether the pathogen caused excessive tillering, as earlier reports stated, is in doubt. Sclerotia form conidia when floating free or detached on moist substrata. Symptoms seem to vary with the growing conditions. GEOGRAPHICAL DISTRIBUTION: Widespread with host (CMI Map 448, ed. 1, 1968). Additional records not mapped are: Costa Rica, Indonesia, Laos, Panama, Peru. TRANSMISSION: Probably largely through the sclerotia; the role of the conidium and ascospore has been little studied. Viability of the sclerotium is variable, depending on temperature and substratum conditions (11: 599; 47, 182), and a period of 6 yr has been reported (20: 381). Both sclerotia and perithecia survive high summer temperatures (46, 1574).


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