Late-season mortality during migration of radio-tagged adult sockeye salmon (Oncorhynchus nerka) in the Columbia River

2005 ◽  
Vol 62 (1) ◽  
pp. 30-47 ◽  
Author(s):  
George P Naughton ◽  
Christopher C Caudill ◽  
Matthew L Keefer ◽  
Theodore C Bjornn ◽  
Lowell C Stuehrenberg ◽  
...  

We radio-tagged 577 adult sockeye salmon (Oncorhynchus nerka) returning to the Columbia River in 1997 to determine how migration behaviors were related to migration success in an altered river system. The probability of successful migration declined dramatically for late-entry individuals, concomitant with declines in discharge and the onset of stressful temperatures. Long dam passage times were not related to unsuccessful migration at most dams. However, when migration histories were analyzed across multiple dams or reservoirs, relatively slow migration was significantly associated with unsuccessful migration, suggesting potential cumulative effects. Median passage times at dams were rapid (7.9–33.4 h), although 0.2%–8% of salmon took more than 5 days to pass. Reservoir passage was also rapid, averaging 36.8–61.3 km·day–1, and appeared to compensate for slowed migration at dams. Rates observed in the unimpounded Hanford Reach suggest that total predam migration rates may have been similar to current rates. Overall, our results suggest that cumulative effects may be more important than negative effects of passage at single dams and that hydrosystem alteration of temperature regimes in the migration corridor may have an important indirect negative impact on adults.

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.


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.


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.


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.


1997 ◽  
Vol 54 (4) ◽  
pp. 847-858 ◽  
Author(s):  
E E Walter ◽  
J P Scandol ◽  
M C Healey

Although sockeye salmon (Oncorhynchus nerka) spend 1-4 years in the ocean and accumulate 99% of adult body weight during this period, their migratory patterns in the Northeast Pacific are not yet well understood. A model of ocean migration based on conjecture from limited catch and tagging data has influenced work in sockeye ecology for the past 20 years. To evaluate this model, we constructed a spatially explicit individual-based model that used ocean surface currents and simple behavioural rules to simulate migration patterns for sockeye from the Fraser River system. We explored several modelled behaviours, including random swimming and swimming with a directional bias during some months. The simulations begin at the time when juveniles leave inside coastal waters and end when return migration begins (a few months before river reentry). We determined that simple undirected swimming for most of the ocean phase (except the first 4 months when smolts are near the coast) provided results that challenged the prevailing model but did not require complex assumptions. The migration patterns generated by these rules compare well both qualitatively and quantitatively with the existing empirical data on British Columbia sockeye distribution and migrations in the ocean.


2009 ◽  
Vol 66 (2) ◽  
pp. 238-246 ◽  
Author(s):  
Harry B. Rich, ◽  
Thomas P. Quinn ◽  
Mark D. Scheuerell ◽  
Daniel E. Schindler

Recent climate changes have had marked effects on the ice-free season and thermal conditions in many high-latitude lakes, but their ecological effects combine with density-dependent processes to affect fish growth and life history. To better understand the relative roles of climate and intraspecific density, we applied Gaussian state–space models to long-term data (1962–2006) on growth of juvenile sockeye salmon ( Oncorhynchus nerka ) in Iliamna Lake, Alaska, USA. Both temperature and density influenced fry size at the end of their first growing season, but the positive effect of temperature exceeded the negative effects of density. Fry growth was affected by the magnitude of their own cohort more strongly than by the previous brood (i.e., yearlings). In contrast, density was more important than temperature in Lake Aleknagik, also in Bristol Bay, over the same period of record, probably because Iliamna Lake is cooler and has generally lower densities of juvenile sockeye salmon than Lake Aleknagik. In both lakes, the size of the fish at the end of the first growing season affects smolt size and age at seaward migration, hence survival at sea and age at maturity, so the relative effects of climate and density depend on the ecological context.


2019 ◽  
Vol 76 (12) ◽  
pp. 2390-2395 ◽  
Author(s):  
Matthew J. Smukall ◽  
Amy Shaw ◽  
Donald C. Behringer

Catch-and-release angling of salmonids is a widely implemented fisheries management strategy intended to provide recreational fishing opportunities while limiting harvest. Previous research has indicated mortality may be low, but the extent of sublethal impacts, including inability to reach spawning grounds or decreased spawning effectiveness, is relatively under-studied. Sockeye salmon (Oncorhynchus nerka) were subjected to simulated catch-and-release events, with a subset also enduring air exposure, to determine how physiological stress influences the ability of sockeye salmon to reach spawning grounds and the viability of eggs produced. Short-term postrelease mortality was highest for fish that were subjected to air exposure, but once recovered, neither simulated catch-and-release nor air exposure had a major impact on their ability to reach spawning grounds. Egg viability was similar between treatment groups, indicating physiological stress associated with the trials did not have a negative impact on reproduction. These results suggest that handling, especially air exposure, is the primary concern and substantially impacts the short-term postrelease mortality of sockeye salmon, which has important implications for management.


2009 ◽  
Vol 66 (6) ◽  
pp. 896-908 ◽  
Author(s):  
Neala W. Kendall ◽  
Thomas P. Quinn

Conspecific salmonid populations often differ in age and body size at maturity, and these differences can cause fishery exploitation rates and patterns of directional selection on size to vary among populations. Based on age and length data on five representative spawning populations of sockeye salmon ( Oncorhynchus nerka ) in the Wood River system, Bristol Bay, Alaska, USA, we estimated exploitation rates and population-specific patterns of selection from a gillnet fishery between 1963 and 2007. Exploitation rates have differed among age groups and have varied greatly over time, likely due to changes in fishery selectivity. Populations with older, larger fish were more heavily exploited than populations with small, young fish. Differential fishery selection was detected among the populations, linked to persistent differences in size and age of fish among the populations. Specifically, we found evidence of stronger size selectivity on populations with smaller-bodied fish and less directional selection on populations dominated by larger-bodied fish. These results reveal the complex variation in the intensity and selectivity of fishing that can result from exploitation of populations that differ in age and size at maturity and shape. Evolutionary responses to this selection may be taking place, but natural processes provide countervailing selection.


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