scholarly journals Migration and survival of Okanagan River Sockeye Salmon Oncorhynchus nerka, 2012–2019

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Josh Murauskas ◽  
Kim Hyatt ◽  
Jeff Fryer ◽  
Elliot Koontz ◽  
Skyeler Folks ◽  
...  

Abstract Background Okanagan River Sockeye Salmon Oncorhynchus nerka (Okanagan Sockeye) are one of two remaining self-sustaining Sockeye Salmon populations in the Columbia River Basin. We used detection histories of smolts implanted with passive integrated transponder (PIT) tags between 2012 and 2019 to estimate survival and behavioral metrics during reintroduction efforts and changing environmental conditions over the monitoring period. Results Smolts migrating to McNary Dam, whose route includes 130 km of the Okanagan River and 388 km of the Columbia River, generally had high survival (mean of 87.0% per 100 km) and fast migration speeds (up to 50 km/day) relative to other salmonids in the region. Smolt-to-adult returns (SARs) ranged from 0.4 to 6.1% and were greater for fish originating from Skaha Lake compared to cohorts tagged in Osoyoos Lake. Most adults returned after 2 years in the ocean (69%), followed by jacks (27%), and adults that spent 3 years at sea (4%), though Skaha Lake adults had a significantly younger age structure than cohorts from Osoyoos Lake. Survival of adults from Bonneville Dam (rkm 235) upstream to Wells Dam (rkm 830) was generally high (80–92%), and migration speed decreased in upstream reaches. Survival from Wells Dam to the Okanagan River was only estimable in 2018, where 64% of adults survived to the spawning grounds. The upstream migration of adult Okanagan Sockeye was significantly compromised during the drought of 2015 when less than 5% of Okanagan Sockeye that returned to the Columbia River reached spawning grounds. Conclusions Our results indicate that Okanagan Sockeye have exceptional survival and migratory ability relative to other salmonids, though poor ocean conditions combined with warming water temperatures in freshwater habitats in recent years have the potential to devastate the population. The success of reintroduction efforts to increase spatial structure and diversity of Okanagan Sockeye is, therefore, critical to maintaining the population in years to come.

1960 ◽  
Vol 17 (3) ◽  
pp. 347-351 ◽  
Author(s):  
J. D. Wood ◽  
D. W. Duncan ◽  
M. Jackson

During the first 250 miles (400 km) of spawning migration of Fraser River sockeye salmon (Oncorhynchus nerka) the free histidine content of the muscle, alimentary tract, and head+skin+bones+tail decreased to a small fraction of the initial value. A further decrease occurred in the levels of this amino acid in the alimentary tract during the subsequent 415-mile (657-km) migration to the spawning grounds, no change being observed with the other tissues. Comparatively small changes in free histidine were found with heart, spleen, liver, kidney and gonads during migration.


2009 ◽  
Vol 297 (4) ◽  
pp. R1136-R1143 ◽  
Author(s):  
Erik Sandblom ◽  
Timothy D. Clark ◽  
Scott G. Hinch ◽  
Anthony P. Farrell

Some male salmonids (e.g., rainbow trout) display profound cardiovascular adjustments during sexual maturation, including cardiac growth and hypertension, and tachycardia has been observed in free-ranging male salmonids near their spawning grounds. In the present study, we investigated cardiac control, dorsal aortic blood pressure, cardiac morphometrics, and hematological variables in wild, sexually maturing sockeye salmon ( Oncorhynchus nerka) with a particular aim to decipher any sex-specific differences. Routine heart rate ( fH) was significantly higher in females (52 vs. 43 beats/min), which was due to significantly lower cholinergic tone (28 vs. 46%), because there were no differences in adrenergic tone or intrinsic heart rate between sexes. No differences in blood pressure were observed despite males possessing an 11% greater relative ventricular mass. Concomitant with higher routine heart rates, female sockeye had significantly higher levels of cortisol, testosterone, and 17β-estradiol, whereas the level of 11-ketotestosterone was higher in males. There were no differences in hematocrit or hemoglobin concentration between the sexes. The findings of this study highlight the importance of considering sex as a variable in research fields such as conservation biology and when modeling the consequences of local and global climate change. Indeed, this study helps to provide a mechanistic basis for the significantly higher rates of female mortality observed in previous studies of wild-caught sockeye salmon.


2012 ◽  
Vol 69 (2) ◽  
pp. 330-342 ◽  
Author(s):  
Eduardo G. Martins ◽  
Scott G. Hinch ◽  
David A. Patterson ◽  
Merran J. Hague ◽  
Steven J. Cooke ◽  
...  

Recent studies have shown that warm temperatures reduce survival of adult migrating sockeye salmon ( Oncorhynchus nerka ), but knowledge gaps exist on where high-temperature-related mortality occurs along the migration and whether females and males are differentially impacted by river temperature. In this study, we monitored 437 radio-tagged Fraser River sockeye salmon and used capture–mark–recapture modelling approaches to investigate whether river thermal conditions differentially influence (i) spatial patterns of survival along a 413-km stretch of migration and (ii) survival of the sexes. Regardless of water temperature, survival decreased in the river section containing the most hydraulically difficult passages of the migration. However, when water temperature was warm (19 °C), survival decreased even further in the final 186 km of the migration prior to reaching the spawning grounds, particularly in females. Female and male survival differed but only when they experienced warm river temperatures. Under such conditions, the overall freshwater migration survival of males was 1.6 times higher (0.79 ± 0.09 standard error, SE) than that of females (0.50 ± 0.11 SE). As maturing female sockeye salmon maintain higher levels of plasma cortisol compared with males, we suspect that females could be immuno-compromised and thus less resistant to pathogens whose rates of development are accelerated by warm temperatures.


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.


2000 ◽  
Vol 78 (6) ◽  
pp. 974-981 ◽  
Author(s):  
Gregory T Ruggerone ◽  
Renn Hanson ◽  
Donald E Rogers

Selective predation by and predation rates of brown bears (Ursus arctos) foraging on spawning sockeye salmon (Oncorhynchus nerka) in a small shallow creek in the Wood River lake system near Bristol Bay, Alaska, were quantified during 1986 and 1990–1992. Bears killed a high proportion of spawning salmon when few salmon entered the creek (92% of 505 fish) and a much smaller proportion when the spawning population reached a historical high (16% of 15 631 fish). Selective predation on salmon that differed in length, sex, and spawning condition was measured by tagging salmon at the mouth of the creek immediately prior to upstream migration and then recovering dead tagged fish during daily surveys of the entire creek. The relative frequencies of large, medium-sized, and small salmon killed by bears indicated that the risk of predation was more than 150% greater for large than for small salmon. A higher proportion of the male salmon population was killed and a greater proportion of male bodies were consumed than female salmon. Selectivity for male salmon increased as the spawning season progressed, possibly because male salmon weakened earlier and lived longer in a weakened state than female salmon. Male salmon were attacked mostly along the dorsal hump area, whereas female salmon tended to be attacked along the abdomen, where eggs could be exposed. Bears selectively killed female salmon prior to spawning during 1 of the 3 years, but only 6.1–7.8% of the female spawning populations were killed prior to spawning. These data support the hypothesis that selective predation by bears may influence the body morphology of spawning salmon.


1997 ◽  
Vol 54 (6) ◽  
pp. 1349-1360 ◽  
Author(s):  
Thomas P Quinn ◽  
Sayre Hodgson ◽  
Charles Peven

We related the arrival timing of adult sockeye salmon (Oncorhynchus nerka) at a series of dams on the Columbia River (Bonneville, McNary, and Rock Island) and Snake River (Ice Harbor) to the changing flow and temperature regimes over the last several decades. The temperatures experienced by sockeye salmon have increased in the lower but not upper reaches of the system, and the flows experienced by the fish have decreased. The Bonneville-McNary travel rate increased from about 22 to 49 km/day, and sockeye salmon now pass McNary Dam about 11 days earlier than in 1954. Both travel rate and arrival date were correlated with temperature increases and flow decreases at McNary during that period. Sockeye salmon arrival at Rock Island Dam (14 days earlier from 1933 to 1994) was also correlated with temperature and flow there. However, the travel rate between McNary and Rock Island dams did not change from 1955 to 1994, despite a decrease in estimated water velocity from 85 to 23 km/day. Sockeye salmon arrival at Ice Harbor Dam has sometimes been bimodal; the first mode's date has not changed, but annual mean dates have been positively correlated with flow and negatively with temperature.


2019 ◽  
pp. 44-45
Author(s):  
Erika Anderson ◽  
Jackie King ◽  
Chrys Neville ◽  
Strahan Tucker ◽  
Terry Beacham

1959 ◽  
Vol 16 (2) ◽  
pp. 235-241 ◽  
Author(s):  
D. R. Idler ◽  
I. Bitners

The absolute changes in fat, protein, water and free and esterified cholesterol for the entire body of standard male and female sockeye salmon (Oncorhynchus nerka) during the Fraser River spawning migration are discussed.The data were obtained for twelve groups of males and twelve groups of females, totalling 216 fish. The fish were caught at three locations: before entering the river, 250 miles up the river, and at one of the spawning grounds 715 miles from the first sampling station.


1994 ◽  
Vol 72 (3) ◽  
pp. 397-405 ◽  
Author(s):  
Chris J. Foote ◽  
Ian Mayer ◽  
Chris C. Wood ◽  
W. Craig Clarke ◽  
J. Blackburn

The evolution of nonanadromous forms of salmonids has been linked to adaptive similarities between migration to the sea and migration to lakes, and to inhibition of smoltification by rapid development rates and early maturation. We examined the seasonal cycle of seawater adaptability in a landlocked (10 000 years) population of kokanee, Oncorhynchus nerka, to determine if the typical anadromous cycle persists in the absence of recent gene flow from sockeye salmon, as would be expected if components of smoltification are beneficial to a lacustrine existence. We also monitored the effects of maturation on seawater adaptability, to determine if they had an inhibitory effect on smoltification, as would be expected if a developmental conflict was responsible for the evolution of nonanadromous forms. Maturation was measured through the growth of gonadal tissue and the increase in circulating testosterone and 11-ketotestosterone. Landlocked kokanee showed the seawater adaptability cycle typical of sockeye salmon, and maturation had no inhibitory effect on seawater adaptability until near, or at, full maturity. We conclude that at least some components of smoltification must be beneficial to a life in lakes to account for the continued maintenance of the cycle. Further, rapid development and maturation on their own do not appear to account for the evolution of nonanadromous populations of O. nerka.


1976 ◽  
Vol 33 (11) ◽  
pp. 2629-2633 ◽  
Author(s):  
Alan V. Nebeker ◽  
Donald G. Stevens ◽  
Richard K. Stroud

Adult sockeye salmon (Oncorhynchus nerka) were exposed to air-supersaturated water in the laboratory from July 8 to August 13, 1974, approximately the same time period that they are exposed to supersaturated water during their movement through the lower and middle sections of the Columbia River. The first mortality occurred after 77 h exposure at 120% saturation; 40% of the fish were dead after 127 h. At 115% saturation the first mortality occurred after 523 h (21 days) and 40% were dead after 835 h (35 days). No further mortality occurred at 120 or 115%. However, at 120 and 115% saturation, survivors exhibited many sublethal lesions such as hemorrhaging and emphysema (bubbles) in the mouth, on the gill arches, body surface, and fins, etc. No deaths or signs of gas bubble disease occurred in fish held at 110% saturation in water 2 ft (60 cm) deep. The lethal threshold was near 114% saturation.


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